Russell’s vipers (Daboia russelii and D. siamensis) are found in 10 South and Southeast Asian countries. Daboia russelii is found west of the Bay of Bengal and D. siamensis is found east of the Bay of Bengal (Thorpe et al. 2007). Bites from Russell's Vipers are the leading cause of fatal snake bite in India, Pakistan, Sri Lanka, Burma, Thailand, and parts of Indonesia. Humans envenomed by these snakes suffer coagulopathy, bleeding, shock, neurotoxicity, acute kidney injury and local tissue damage leading to severe morbidity and mortality. An unusual complication of Russell’s viper bite envenoming known from Burma (D. siamensis) and southern India (D. russelii) is hypopituitarism. Antonypillai et al. (2011) reported this complication from Sri Lanka as well, reviewed the literature on this phenomenon (which may develop years after recovery from acute effects of the snakebite) , and made recommendations for endocrine investigation and management.
The dangerously venomous Russell's Viper (Daboia russelii) is one of several species in the genus Daboia, which includes one or two North African species (mauritanica, deserti) formery included in Macrovipera, the Levantine D. palaestinae (formerly Vipera palaestinae), and the South Asian (Daboia russelii), which reaches the Middle East only peripherally in Pakistan. Daboia is characterized by a raised numbers of body scales. (Stümpel and Joger 2009 and references therein)
According to Leviton et al. (2003), Russell's Viper (Daboia russelii) occurs in Myanmar (Ayeyarwady, Bago, Magway, Mandalay, Sagaing , and Yangon Divisions and Shan State), as well as southern China, Taiwan, India, Pakistan, Sri Lanka, Bangladesh, Thailand, and Indonesia (Java east to Lomblen Island [=Lembata]). This species has not been recorded from Malaysia or Sumatra.. It primarily inhabits lowland areas. Thorpe et al. (2007) studied the phylogeography of Russell's Viper (using a combination of mitochondrial genetic data, morphometrics, and color pattern) and concluded that two distinct species should be recognized: D. russelii throughout South Asia, west of the Bay of Bengal, and D. siamensis in Southeast Asia, east of the Bay of Bengal.
In Myanmar, Russell's Vipers are common throughout the central dry zone and Ayeyarwady (= Irrawaddy) Delta, where they are often encountered in agricultural areas and paddies as well as in open grasslands.These snakes are active at night.
This may be the most common of the dangerously venomous snakes in southern Asia, where it accounts for more than half of all reported snakebites. Hiremath et al. (2014) note that Russell's Viper is one of the four snake species long believed to account for the large majority of snakebite cases in India, often known as "the Big Four"--the other three species being another viper, Saw-scaled Viper (Echis carinatus), and two elapids, Indian Cobra (Naja naja) and Common Krait (Bungarus caeruleus) (with bites from other dangerously venomous snakes such as King Cobra, Ophiophagus hannah, being relatively rare). Hiremath et al. compare the impacts of the venoms of these four types of snakes on blood coagulation. (Note, however, that Simpson et al [2007] have argued that the "Big Four" concept has resulted in significantly misdirected epidemiological and treatment efforts, e.g., through the misdiagnosis of envenomations actually attributable to the Hump-nosed Pit Viper (Hypnale hypnale). Hung et al. (2002) reviewed Russel's Viper snakebites in Taiwan and noted that symptoms appear to differ from those reported from some other parts of Asia.
Several color pattern variants have been recognized as subspecies:D. r. siamensis from southern China, central and southern Myanmar, and central Thailand; D. r. formosensis from eastern China and Taiwan; and the nominate form from India, Pakistan, and Bangladesh. Its unusual distribution (eespecially its erratic distribution in Indonesia) suggests that it has been moved over long distances in the course of commercial exchange, likely during the 18th and 19th centuries. Russell’s Viper is a prolific breeder and young could plausibly have been moved along with plants or other goods in the early days of colonial expansion.
Although this species was named in honor of Patrick Russell, the original description used just one “l” in the specific epithet, which Leviton et al. (2003) therefore consider to be the correct spelling. Mallow et al. (2003) provide additional information on this species.
(Leviton et al. 2003 and references therein)
Kularatne et al. (2014a) reported on the problem of Russell's Viper snakebites in Sri Lanka, including a discussion of diagnosis and treatment.
Tun-Pe et al. (1995) studied the properties of the venom of Russell’s Vipers of varying ages.
Kavitha et al. (2014a) reported on the presence of Sparganum cestode larvae parasitizing two Russell's Vipers in southern India. Kavitha et al. (2014b) reported the presence of Kalicephalus hookworms (Nematoda: Diaphanocephalidae) in the stomach and intestine of a captive Russell's Viper.
Patel and Tank (2014) describe both the typical body coloration, as well as that of a rare whitish color morph.
Leviton et al. (2003) provide a technical description of Russell's Viper: No sensory pit between nostril and eye. Head very distinct from neck, above covered by small, keeled, imbricate scales, 6-9 between narrow supraoculars; nostril large, in large nasal shield which, below is fused to the rostral; eye, with vertically elliptic pupil, is surrounded by 10-15 small scales, 3-4 rows of small scales separatingthe circumocular scales from the upper labials; temporals small; 10-12 upper labials; 27-33 longitudinal rows of scales at midbody, all except outermost row strongly keeled; ventrals 153-180; subcaudals 41-64, all paired; color above light brown with three longitudinal seriesof large black-margined brown spots or blotches, the vertebral series often merging to form a chain-like longitudinal strip, occasionally an additional longitudinal series of small dark spots between the vertebral and lateral series. Yellowish white below occasionally with dark brown markings. Total length to 1600 mm not uncommon.
Daboia is a monotypic genus of venomous Old World viper. The single species, D. russelii (Russel's viper) is found in Asia throughout the Indian subcontinent, much of Southeast Asia, southern China and Taiwan. The species was named in honor of Patrick Russell (1726–1805), a Scottish herpetologist who first described many of India's snakes; and the name of the genus is from the Hindi word meaning "that lies hid," or "the lurker."Daboia russelii is one of the "big four" snakes responsible for causing the most snakebite incidents and deaths in South Asia (mostly India).They have a wide distribution and occur frequently in highly-populated areas. Two subspecies are currently recognized, D. r. siamensis and D. r. russelii.
(Modified from Wikipedia 2013)
Zmije řetízková (Daboia russelli) je jedovatý had z jižní a jihovýchodní Asie, jediný z rodu Daboia. Areál jejího rozšíření obsahuje oblast od Pákistánu, přes Indii, Bangladéš, Nepál, jižní Čínu, Srí Lanku, Taiwan, Myanmar, Kambodžu, Thajsko, až po Indonésii, kde se vyskytuje na východní Jávě, ostrovech Lomben, Komodo, Endeh a Flores. Populace v Laosu, Vietnamu a na Sumatře není prokázána.
Ještě před nedávnem bylo uznáváno několik poddruhů, dnes jsou uznávány již jen dva:[zdroj?]
Zmije má klasické zmijí tělo, oválné, tlusté, a s oválnou hlavou. Dosahuje až 120 cm délky, ale největší údaje hovoří až o 185 cm. Občas jsou k nalezení jedinci dlouzí 160 cm, ale to už je vzácné. Had má výrazný nasální štítek. Zbarvení je různorodé, od šedé, přes hnědou až po pískově žlutou. Výraznou dominantou jsou oválné skvrny uspořádané pravidelně na hřbetu a bocích. Díky nim dostala své české jméno, připomínají totiž řetěz. Okraje skvrn jsou často bíle lemované, někdy se i navzájem dotýkají. Pro svou krásnou kůži bývá často lovena.
Had se vyskytuje v různorodém prostředí, od nížin až po hory, od deštných lesů až po horské lesy. Dosahuje výšky i 3000 m n. m. Stejně různorodé je i spektrum potravy. Loví vše od hmyzu, obojživelníků, plazů, až po ptáky a savce. Samice rodí živá mláďata, většinou 20 až 40 kusů, ale občas i přes 60!
Zmije řetízková je jeden z nejnebezpečnějších hadů světa. Pro její velké rozšíření a silný jed má na svědomí mnoho úmrtí především v Indii. Navíc je aktivní hlavně v noci, takže se občas stane, že leze do lidských příbytků, kde je nebezpečí uštknutí ještě větší. Ročně způsobí smrt několika tisíc lidí. Její jed se sice nedá srovnávat s jedy kober, ale zmije ho má daleko větší množství. V jihovýchodní Asii je známá jako zabiják, tři čtvrtiny všech úmrtí po uštknutí hadem v oblasti jsou způsobeny právě zmijí řetízkovou. Uštknutí je provázeno prudkou bolestí, otoky, krvácením a nakonec kolapsem dýchacího ústrojí. V Indii je známa "Velká indická čtyřka": kobra indická, bungar modravý, zmije řetízková a zmije paví. Nejvíc úmrtí způsobí právě zmije řetízková.
Obrázky, zvuky či videa k tématu zmije řetízková ve Wikimedia Commons
Tento článek není dostatečně ozdrojován a může tedy obsahovat informace, které je třeba ověřit.Zmije řetízková (Daboia russelli) je jedovatý had z jižní a jihovýchodní Asie, jediný z rodu Daboia. Areál jejího rozšíření obsahuje oblast od Pákistánu, přes Indii, Bangladéš, Nepál, jižní Čínu, Srí Lanku, Taiwan, Myanmar, Kambodžu, Thajsko, až po Indonésii, kde se vyskytuje na východní Jávě, ostrovech Lomben, Komodo, Endeh a Flores. Populace v Laosu, Vietnamu a na Sumatře není prokázána.
Die Kettenviper (Daboia russelii) ist eine Art der Orientalischen Vipern (Daboia). Sie ist in zwei Unterarten in Asien von Indien über Teile Chinas bis nach Südostasien und Indonesien verbreitet. Die Kettenviper gilt wegen ihres extrem wirksamen Gifts und ihres häufigen Auftretens im Siedlungsbereich als gefährlichste Schlange Südostasiens; pro Jahr werden dieser Art etwa 900 Todesfälle zugeschrieben.
Die Länge der Kettenviper variiert regional sehr stark. Inselpopulationen auf Sri Lanka bleiben im Regelfall relativ klein mit Durchschnittslängen von 0,90 m und Maximallängen von 1,5 m.[1] In China werden die Schlangen im Mittel etwa 1,0 bis 1,20 m lang mit einer Maximallänge von 1,67 m[2], und in Indien liegt die mittlere Länge bei 1,20 m und die Maximallänge bei 1,85 m.[3] Auf den relativ kurzen Schwanz entfällt dabei etwa ein Sechstel der Körperlänge, der Kopf einer 1,20 m langen Schlange ist etwa 5 Zentimeter lang. Der Körperbau ist im Vergleich zu anderen Vipern etwas schlanker. Der Kopf ist abgeflacht und annähernd dreieckig, er setzt sich deutlich vom Körper ab.
Die Schnauzenspitze ist aufgewölbt und vorn abgerundet, die darüberliegenden Nasenlöcher sind relativ groß und mit einem einzelnen, großen Nasenschild (Nasale) abgedeckt. Am vorderen Ende liegt das Nasorostrale an, welches wiederum über dem beinah quadratischen Rostrale am Vorderende der Schnauze liegt, die Supranasalia sind stark gebogen und mondsichelartig geformt. Der Oberkopf selbst ist mit kleinen und ungleichmäßigen Schuppen bedeckt. Die Überaugenschilde (Supraocularia) sind sehr schmal und ungeteilt, sie werden durch sechs bis neun Schuppen voneinander getrennt. Die Augen sind groß und jeweils von 10 bis 15 Schuppen umgrenzt. Die Iris ist goldgelb, die Pupille ist senkrecht. Unterhalb der Augen liegen drei bis vier Reihen von Unteraugenschilden (Subocularia) und darunter schließen sich die zehn bis zwölf Oberlippenschilde (Supralabialia) an, von denen der vierte und fünfte signifikant größer als die restlichen sind. An der Kopfunterseite befinden sich zwei Paar Kinnschilder, von denen der vordere deutlich vergrößert ist.
Die für Vipern typischen vorn im Oberkiefer stehenden Giftzähne sind ausklappbar und mit einem inneren Giftkanal ausgestattet (solenoglyphe Giftzähne). Sie sind bis zu 16 Millimeter lang, wobei mindestens zwei und maximal sechs Zahnpaare vorhanden sind. Die vordersten Zähne sind besonders stark ausgebildet und enthalten den eigentlichen Giftapparat. Sie werden bei Verlust durch die dahinterstehenden Zahnpaare, die ebenfalls mit einem Giftkanal ausgestattet sind, ersetzt. Außerdem besitzt die Art beidseitig 9 bis 10 Zähne auf dem Flügelbein (Pterygoid), 12 bis 13 auf der Mandibula und 3 Zähne auf dem Palatinum.
Der Körper ist flach gebaut und wird in der Mitte zylindrisch. Die Rückenschuppen sind stark gekielt, nur die unterste Reihe ist glatt ausgebildet. Der Rücken wird in der Körpermitte von 27 bis 33 Schuppenreihen abgedeckt, wobei die Anzahl regional unterschiedlich ist. Der Bauch zeigt 153–180 Bauchschuppen (Ventralia), der daran anschließende Analschild ist ungeteilt. Der kurze Schwanz hat 41 bis 68 paarige Subcaudalia.
Die Färbung variiert von einem dunklen Gelb über hellbraun bis erdbraun. Über den Rücken ziehen sich vom Kopf bis zum Schwanz drei Reihen von Fleckenbändern, wobei die beiden seitlichen Reihen in Einzelflecken aufgelöst sind. Dabei hat jeder Fleck eine dunkle Umrandung, die wiederum von einer Reihe heller Schuppen umrandet wird. Auf dem Kopf befinden sich zwei dunklere Flecken oberhalb der Augen, von denen sich eine V- oder X-förmige hellbraune bis rosafarbene Zeichnung zur Schnauzenspitze zieht. An den Kopfseiten zieht sich hinter den Augen ein bräunlicher Augenstreif nach hinten. Der Bauch ist weiß, gelblich oder rosafarben und kann ungleichmäßig dunkel gefleckt sein.
Insgesamt kann die Färbung und vor allem die Zeichnung der Tiere regional sehr unterschiedlich sein, daher wurden in der Vergangenheit fünf bis sieben Unterarten beschrieben. Nach einer umfassenden Untersuchung wurde diese Anzahl 1992 auf zwei derzeit anerkannte Unterarten reduziert, die westliche D. russelii russelii und die südöstliche D. russelii sublimitis.[4][5]
Die Kettenviper ist über ein sehr großes Gebiet im zentralen und südlichen Asien verbreitet. Sie kommt auf dem indischen Subkontinent mit Indien, Pakistan und Bangladesch, auf Sri Lanka, im südlichen China und auf Taiwan, in Myanmar, in Thailand sowie auf einigen Inseln Indonesiens vor. Dabei gibt es sowohl große, zusammenhängende Vorkommensgebiete als auch Regionen mit eher lückenhafter und isolierter Verbreitung. Besonders isoliert von anderen Vorkommen sind die Kettenvipern der indonesischen Inseln Komodo, Flores, Lembata und des südlichen Java, die mehr als 2000 Kilometer von den nächsten Festlandpopulationen in Thailand entfernt sind. Sumatra, Borneo, der größte Teil Javas und auch die malayische Halbinsel weisen keine Kettenvipern auf.[5]
Als Lebensraum bevorzugt die Art vor allem mäßig feuchte Habitate in niedrigeren Höhenlagen. Sie ist vor allem im Grasland und in Buschlandschaften zu finden, häufig zudem in Ruderalflächen, Randvegetation am Ufer von Flüssen sowie in Agrarflächen und Gärten. Dadurch findet man sie vor allem in Indien und einigen anderen Ländern häufig im Bereich menschlicher Ansiedlungen und landwirtschaftlich genutzter Gebiete. Die Art kommt auch in Gebieten mit dichtem Gebüsch vor, meidet jedoch geschlossene Waldgebiete mit dichter Vegetation, außerdem Sumpfland und permanent feuchte Gebiete. Die maximal besiedelten Höhenlagen liegen bei etwa 2300 bis 3000 Metern NN, meistens jedoch deutlich niedriger.
Die Kettenviper ist im Normalfall nachtaktiv und hat ihre Hauptaktivitätszeit in der Zeit nach Sonnenuntergang, bei besonders kalter Witterung kann sich die Aktivität jedoch auch in den Tag verschieben. Sie ist primär bodenlebend und hält sich meistens in Gebüschen oder hohem Gras auf, wo sie durch ihre Zeichnung gut getarnt ist. Ihre Fortbewegung wird als träge und gleitend beschrieben, wobei besonders junge Tiere deutlich aktiver sind.
Bei Bedrohung rollt sich die Schlange zusammen und hebt den Oberkörper an, dabei zischt sie laut und deutlich hörbar. Aus dieser Position heraus stößt sie beim Biss mit großer Kraft vorwärts, wobei fast der gesamte Körper Bodenkontakt verlieren kann. Im Regelfall sind ausgewachsene Schlangen deutlich ruhiger und weniger reizbar als Jungschlangen.
Die Nahrung der Kettenviper besteht vor allem aus Kleinsäugern wie verschiedenen Ratten oder Mäusen sowie aus Vögeln. Vor allem für Südindien wird eine Spezialisierung auf die Indische Rennmaus beschrieben. Ansonsten reicht das sehr breite Spektrum an potentiellen Beutetieren von den bereits genannten Kleinsäugern bis hin zu Hauskatzen, Skorpionen und anderen Gliederfüßern. Jungtiere jagen hauptsächlich Eidechsen und auch Insekten. Vor allem aufgrund der dort häufig vorkommenden Mäuse leben die Schlangen oft auf Feldern und in der Nähe menschlicher Behausungen, wodurch es vergleichsweise häufig zum Aufeinandertreffen von Mensch und Kettenviper kommt.
Die Schlange pirscht sich an ein potenzielles Beutetier an und stößt dann in einem geeigneten Moment zu. Nach dem Biss zieht sie sich sofort wieder zurück und wartet, bis das Beutetier verendet ist. Die Beute wird dann mit dem Kopf voran verschlungen.
Die Paarung der Kettenviper erfolgt im Regelfall von April bis Juli. Die Jungtiere werden von Mai bis November geboren, wobei die meisten Geburten im Juni und im Juli zu verzeichnen sind. Die Schlange ist lebendgebärend (ovovivipar) und bringt 20 bis 40 Jungschlangen zur Welt, die größten dokumentierten Würfe bestanden aus etwa 65 Jungschlangen. Die Jungtiere sind bei der Geburt zwischen 215 und 260 Millimeter lang. Die Geschlechtsreife wird nach zwei bis drei Jahren mit etwa einem Meter Körperlänge erreicht.
→ Hauptartikel: Orientalische Vipern#Systematik
Die Kettenviper wurde von George Shaw und Frederick Polydore Nodder 1797 erstmals wissenschaftlich als Coluber russelii beschrieben und damit zu den damals bekannten Nattern gestellt. Namensgeber war der Herpetologe Patrick Russell (1726–1805), der als Autor der Bücher An Account of Indian Serpents (1796) und A Continuation of an Account of Indian Serpents (1801) bekannt wurde. In ihrer Erstbeschreibung kam es allerdings zu einem Schreibfehler, da sie den Namen nur mit einem „l“ statt zweien schrieben. Kurz darauf kam die korrigierte Bezeichnung russelli, später zusätzlich russellii – beide sind jedoch nach der Prioritätsregel des International Code of Zoological Nomenclature (ICZN) ungültig. 1803 wurde die Art erstmals durch François Marie Daudin als Vipera daboia in die Gattung der Echten Ottern und Vipern eingeordnet und verblieb dort unter verschiedenen Synonymen bis in die 1990er Jahre, wobei sie auch mehrfach von verschiedenen Autoren der Gattung Daboia zugeschlagen wurde.
1992 erfolgte eine Revision der Gattung Vipera, bei der sie auf der Basis von biochemischen Merkmalen endgültig als einzige Art der Gattung Daboia zugeordnet wurde, dabei wurde außerdem die Gattung der Großvipern (Macrovipera) gebildet.[6]
Durch Lenk et al. 2001 wurde diese Zusammenstellung allerdings angezweifelt.[7] Auf molekularbiologischer Basis wurde die Zuordnung der afrikanischen Macrovipera sowie der Palästinaviper zur Gattung Daboia vorgeschlagen. Diese Ansicht wird bestätigt durch Garrigues et al. 2004: Wie bei Lenk et al. 2001 ist die Gattung der Großvipern in der aktuellen Zusammenstellung paraphyletisch, die Kettenviper bildet ein Taxon mit der Palästinaviper und den ehemaligen afrikanischen Großvipernarten.[8] Mallow et al. 2003 ordnete entsprechend die Palästinaotter in die Gattung ein,[9] die Atlasotter wurde 2008 von Wüster et al. auf Basis der Ergebnisse von Lenk et al. zu Daboia gestellt.[10]
Wie die meisten Viperngifte ist auch das Gift der Kettenviper vor allem hämotoxisch, es zerstört also vor allem Zellen des Bluts und die sie umgebenden Gewebe durch verschiedene Proteasen. Hämotoxine führen zu umfassenden Gewebezerstörungen, inneren Blutungen und Schwellungen sowie Nekrosen und sind sehr schmerzhaft. Zu den wirksamsten Bestandteilen des Gifts gehören bei der Kettenviper allerdings Proteine, die die Blutgerinnung unterdrücken und damit gemeinsam mit den gewebezerstörenden Anteilen innere Blutungen verursachen. Blutungen treten dabei unter der Haut, in Nasen- und Mundhöhle und vor allem auch in Darm und Gehirn des Opfers auf. Neben Gehirnblutungen ist ein akutes Nierenversagen durch Nierenblutungen die Hauptursache für den Tod der Opfer.
Die Zusammensetzung des Gifts ist je nach Population der Kettenviper sehr variabel und daher ist auch die Wirkung je nach Lokalität teilweise sehr unterschiedlich. Das Gift besteht zu etwa 57 bis 70 Prozent aus Proteinen, davon wiederum entfallen etwa 70 Prozent auf Phospholipase A2, von der allerdings sieben unterschiedliche Isoenzyme bestimmt werden konnten. Die Zusammensetzung des Gifts korreliert nach unterschiedlichen Untersuchungen weder mit der Lokalität noch mit dem Aussehen der Tiere. Bei Untersuchungen mit Antiveninen wurde festgestellt, dass diese durchaus bei weit auseinanderlebenden Populationen beider Unterarten wirken können, andererseits können die Antivenine bei einer Population wirksam sein und bei einer dicht benachbarten Populationen unwirksam.[5]
Die Wirkung des Kettenvipergifts ist sehr stark. Die letale Dosis LD50 bei Mäusen, denen das Gift intravenös gespritzt wurde, liegt bei nur 0,08 bis 0,31 Mikrogramm pro Gramm Körpergewicht. Wird das Gift in die Bauchhöhle gespritzt (intraperitoneal), reichen 0,4 Mikrogramm pro Kilogramm Körpergewicht als LD50. Bei den meisten Menschen sind Giftmengen von 40 bis 70 mg tödlich, wodurch das Gift im Vergleich zu fast allen landlebenden Schlangen wie den Kobras, Klapperschlangen, Kraits, Lanzenottern oder auch Mambas deutlich wirksamer ist. Bei einem durchschnittlichen Erstbiss gibt die Kettenviper etwa 72 mg Gift ab, bei Einzelexemplaren konnten jedoch auch 150 bis 250 mg Gift pro Biss festgestellt werden, dies entspricht dem Gesamtinhalt der Giftdrüsen der Tiere.[11]
Das Gift der Kettenviper (eng. Russell's viper venom) wird zur Diagnostik eines Antiphospholipid-Syndroms eingesetzt.[12] Hierbei aktiviert im Diluted Russel-Viper-Venom-Time-Test (dRVVT) das Schlangengift in-vitro die Gerinnung zum Nachweis eines Lupus-Antikoagulans.[13]
Entsprechend der Wirkung des Gifts und der häufigen Zusammentreffen zwischen Mensch und Kettenviper vor allem in der Nähe von Siedlungen oder auf landwirtschaftlich genutzten Flächen wird die Kettenviper als die gefährlichste Giftschlange Indiens und Südostasiens eingeschätzt. Pro Jahr werden der Kettenviper etwa 2000 Bisse und etwa 900 Todesfälle zugeschrieben.
In Indien wird die Art gemeinsam mit der Brillenschlange (Naja naja), der Sandrasselotter (Echis carinatus) und dem Indischen Krait (Bungarus caeruleus) zu den Big Four gestellt, den vier Schlangenarten, die allein fast 100 Prozent der Todesfälle Indiens durch Schlangenbisse verursachen. Hier stammen etwa 34 Prozent aller Schlangenbisse von der Kettenviper, und etwa 30 Prozent dieser Begegnungen enden tödlich. In Südchina dagegen stammt im Durchschnitt nur ein Biss unter 640 von der Kettenviper.[11]
Die Kettenviper ist nur in Teilen ihres Verbreitungsgebietes durch aktive Jagd bedroht, im größten Teil ist sie regelmäßig bis häufig anzutreffen. Die Jagd erfolgt dabei vor allem in den Gebieten, in denen ihre Haut zu Schlangenleder verarbeitet wird oder in denen sie wie andere Schlangen auch gegessen wird. Durch Lebensraumzerstörung ist die Kettenviper dagegen kaum betroffen, da sie sich auch in landwirtschaftlich genutzten Gebieten oder Gärten ansiedelt und nur in enger besiedelten Stadtgebieten keinen Lebensraum findet.
Die Informationen dieses Artikels entstammen zum größten Teil den unter Literatur angegebenen Quellen, darüber hinaus werden folgende Quellen zitiert:
Die Kettenviper (Daboia russelii) ist eine Art der Orientalischen Vipern (Daboia). Sie ist in zwei Unterarten in Asien von Indien über Teile Chinas bis nach Südostasien und Indonesien verbreitet. Die Kettenviper gilt wegen ihres extrem wirksamen Gifts und ihres häufigen Auftretens im Siedlungsbereich als gefährlichste Schlange Südostasiens; pro Jahr werden dieser Art etwa 900 Todesfälle zugeschrieben.
घोणस (शास्त्रीय नाव : Daboia, उच्चार: डाबोया; इंग्लिश: Russell's viper) हा आशिया खंडातील भारतीय उपखंड, आग्नेय आशिया, दक्षिण चीन, तैवान या भूप्रदेशांमध्ये आढळणारा विषारी साप आहे. हा महाराष्ट्रामधील चार प्रमुख विषारी सापांपैकी एक साप आहे.
घोणस मुख्यत्वे जंगले तसेच ग्रामीण भाग पसंत करतो.
घोणसाला ओळखण्याची मुख्य खूण म्हणजे त्याच्या अंगावरील साखळीसारख्या दिसणार्या तीन समांतर रेषा असतात. घोणस हिरवा, पिवळा, हलका, करडा रंग व इतर अनेक रंगछटांमध्ये आढळतात. या सापाचे वैशिष्ट्य म्हणजे याचे विषाचे दात तोंडात दुमडू शकतो. सावजाला एकदा विषाने मारल्यानंतर बहुतेक सापांना शिकार खाताना विषाचे दात अडचण बनतात. परंतु उत्क्रांतीमध्ये या सापाने आपले विषाचे दात दुमडून घेण्याची कला अवगत केली आहे. त्यामुळे कधीकधी हा साप चावताना विषारी दातांचा उपयोग करीत नाही. याला कोरडा चावा असे म्हणतात.
घोणसाचे फुत्कार एखाद्या कुकराच्या शिट्टीप्रमाणे असतात.
घोणसाचे वैशिष्ट्य म्हणजे तो पोटामध्ये अंडी उबवतो व पिल्ले अंड्यांतून बाहेर आल्यानंतर बाहेर काढतो. त्यामुळे कित्येकांचा असा अपसमज आहे, की घोणस सस्तन प्राण्यांप्रमाणे पिल्लांना जन्माला घालतात.
घोणसाचे विष अतिशय जहाल असते.त्याचे विष Vasculotoxic प्रकारचे आहे. हे विष मुख्यत्वे रक्ताभिसरण संस्थेवर हल्ला चढवते. विषाच्या या गुणधर्मामुळे चाव्यानंतर रक्तातील गुठळ्या करू शकणार्या प्रथिनांचा नाश होऊ लागतो. त्यामुळे चाव्यानंतर जखमेतून भळाभळा वाहणारे रक्त लवकर थांबत नाही. थोड्या वेळाने नाकपुड्या, कानांतून व गुदद्वारातून रक्त स्रवू लागते. विषावरती प्रतिविषाचे औषध न मिळाल्यास एका दिवसात मृत्यू ओढवू शकतो.
घोणस चावल्यानंतर जखमेभोवती कोणत्याही प्रकारची पट्टी लावू नये; असे केल्यास रक्त साखळून चावलेला भाग कायमचा निकामी होण्याची शक्यता असते. घोणस चावल्यानंतर लवकरात लवकर व्यक्तीला प्रतिविषाचे औषध देणे, हाच सर्वोत्तम उपाय आहे.रुग्णास धीर द्यावा. अनेक वेळेस साप विषारी आहे की नाही हे माहीत नसते. अनेक वेळा घाबरून रुग्णाचा मृत्यू होतो. म्हणून रुग्णास मानसिक धीर देणे गरजेच आहे. त्या व्यक्तीस पाणी प्यायला देऊ नये.
घोणस (शास्त्रीय नाव : Daboia, उच्चार: डाबोया; इंग्लिश: Russell's viper) हा आशिया खंडातील भारतीय उपखंड, आग्नेय आशिया, दक्षिण चीन, तैवान या भूप्रदेशांमध्ये आढळणारा विषारी साप आहे. हा महाराष्ट्रामधील चार प्रमुख विषारी सापांपैकी एक साप आहे.
रसेल की सांप (Daboia russelii ) है एक प्रजाति का विषैला सांप में परिवार Daboia एक Monotypic प्रतिरूपी Viperidae जीनस का विषैला दुनिया के पुराने वाइपर। एकल सदस्य प्रजातियों, डी russelii, में पाया जाता है Asia एशिया भर में Indian_subcontinent भारतीय उपमहाद्वीपमें ज्यादा के Southeast_Asia दक्षिण पूर्व एशिया, दक्षिणी China चीन और Taiwan ताइवान. प्रजातियों में नामित किया गया था के सम्मान Patrick_Russell_(herpetologist) पैट्रिक रसेल (1726-1805), एक Scotland स्कॉटिश Herpetologist herpetologist जो पहले वर्णित कई के India भारत's सांप, और नाम के जीनस से है Hindi हिंदी शब्द का अर्थ है "निहित है कि छिपा", या "lurker". से अलग किया जा रहा एक सदस्य के Big_Four_(Indian_snakes) चार बड़े सांप भारत में, Daboia भी एक पीढ़ी पैदा करने के लिए जिम्मेदार सबसे Snakebite सर्पदंश की घटनाओं और मौतों के बीच सभी विषैला सांप के खाते में कई कारकों, इस तरह के रूप में उनके व्यापक वितरण, आम तौर पर आक्रामक व्यवहार, और अक्सर घटना में अत्यधिक आबादी वाले क्षेत्रों में।
D. russelii विकसित कर सकते हैं करने के लिए एक अधिकतम कुल लंबाई (शरीर + पूंछ) के 166 सेमी (5.5 फीट) है और औसत के बारे में 120 सेमी (4 फीट) पर मुख्यभूमि एशियाई आबादी, हालांकि, द्वीप की आबादी हो सकता है थोड़ा छोटे औसत पर. यह अधिक slenderly निर्मित की तुलना में सबसे अन्य वाइपर.Ditmars (1937) ने निम्नलिखित आयाम के लिए एक "उचित आकार के वयस्क नमूना"
कुल लंबाई 4 ft., 1 इंच 124 सेमी लंबाई की पूंछ 7 इंच 18 सेमी परिधि 6 इंच 15 सेमी चौड़ाई के सिर 2 इंच 5 सेमी लंबाई के सिर 2 इंच 5 सेमीसिर चपटा है, त्रिकोणीय, और अलग से गर्दन. थूथन कुंद है, गोल है, और उठाया है। नाक बड़ा कर रहे हैं, प्रत्येक के बीच में एक बड़ा, एकल नाक पैमाने परहै। के निचले छोर नाक छू लेती है nasorostral. के supranasal एक मजबूत वर्धमान आकार और अलग नाक से nasorostral anteriorly. के व्याख्यान चबूतरे वाला है के रूप में व्यापक रूप में यह अधिक है।
सिर के ताज के साथ कवर किया जाता है अनियमित, दृढ़ता से खंडित तराजू. के supraocular तराजू कर रहे हैं, संकीर्ण, एक, और द्वारा अलग छह से नौ तराजू सिर के पार है। आंखों बड़े के साथ flecked, पीले या सोने के लिए, और से घिरा हुआ 10-15 circumorbital तराजू. साँप 10-12 supralabials, चौथे और पांचवें कर रहे हैं जो की काफी बड़ा है। आंख से अलग है supralabials से तीन या चार पंक्तियों के suboculars. के दो जोड़े की ठोड़ी ढाल, सामने की जोड़ी है, विशेष रूप से बढ़ी हुई है। दो दाढ़ की हड्डी का हड्डियों का समर्थन कम से कम दो और ज्यादा से ज्यादा पांच या छह जोड़े के नुकीले एक समय में: पहले से सक्रिय हैं और बाकी के प्रतिस्थापन. नुकीले प्राप्त की लंबाई 16.5 मि॰मी॰ (0.65 इंच) में औसत नमूना है। शरीर मोटा है, के पार अनुभाग है, जो के लिए गोल गोल है। के पृष्ठीय तराजू दृढ़ता से कर रहे हैं keeled; केवल सबसे कम पंक्ति चिकनी है। के मध्य शरीर, पृष्ठीय तराजू संख्या 27-33. के उदर तराजू संख्या 153-180. के , थाली विभाजित नहीं है। पूंछ कम है — के बारे में 14% की कुल लंबाई के साथ बनती subcaudals नंबर 41-68.
Dorsally, रंग पैटर्न के होते हैं, एक गहरे पीले, भूरे, लाल या भूरे रंग की जमीन का रंग, के साथ तीन श्रृंखला के गहरे भूरे रंग के धब्बे चला कि शरीर की लंबाई है। इन स्थानों में से हर एक के चारों ओर रिंग, बाहरी सीमा का जो तेज है के साथ एक रिम के साथ सफेद या पीले रंग की है। पृष्ठीय धब्बे, जो आम तौर पर संख्या 23-30, हो सकता है एक साथ हो जाना है, जबकि पक्ष के धब्बे हो सकता है। सिर की एक जोड़ी है, विशिष्ट काले धब्बे, एक पर प्रत्येक मंदिर के साथ एक साथ, एक गुलाबी, सामन, या भूरा वी या एक्स अंकन है कि रूपों एक शीर्ष की ओर थूथन. आँख के पीछे एक अंधेरे लकीर में उल्लिखित सफेद, गुलाबी, या शौकीन है। के वेंटर है सफेद, सफेद, पीले या गुलाबी, अक्सर के साथ एक अनियमित बिखरने के काले धब्बे.
, अंग्रेजी में आम नाम के डी russelii शामिल रसेल की सांप, श्रृंखला सांप, भारतीय रसेल की सांप, आम रसेल की सांप, सात तेज गेंदबाज, श्रृंखला सांप, और कैंची साँप। इससे पहले, एक अन्य आम नाम इस्तेमाल किया गया था का वर्णन करने के लिए एक उप-प्रजाति है कि अब भाग के synonymy के इस फार्म: श्रीलंकाई रसेल की सांप के लिए डी. आर. pulchella.
में भारतीय उपमहाद्वीप, यह जाना जाता है के रूप में daboia (दबौया) में हिंदी, पंजाबी, और हिंदुस्तानी; बोरा (বোড়া), चन्द्र बोरा (চন্দ্রবোড়া), या uloo बोरा (উলূবোড়া) में बांग्ला; chitalo या khadchitalo में गुजराती; kolakumandala या mandaladha haavu (ಮಂಡಲದ ಹಾವು) में कन्नड़; गुणों पर कश्मीरी; raktamandali, chenathandan, vattakoora, रक्त anali, या thavitta (അണലി) में मलयालम; ghonas (घोणस, घोण्या), tawarya में मराठी; चंदन boda(ଚନ୍ଦନ ବୋଡା) में Odia; koraile में सिंधी; thith polonga (තිත් පොලඟා) में सिंहली; retha aunali या kannadi viriyan (கண்ணாடி விரியன்) में तमिल; కాటుక రేకుల పాము (katuka rekula paamu) या రక్తపింజర (raktha penjara/penjari) में तेलुगू; और पिली kandhodi में तुलुहै।
D. russelii में पाया जाता है, भारत, श्रीलंका, बांग्लादेश, नेपाल, म्यांमार, थाईलैंड, पाकिस्तान, कम्बोडिया, तिब्बत, चीन (Guangxi, गुआंग्डोंग), ताइवान और इंडोनेशिया (Endeh, Flores, पश्चिम जावा, Komodo, और Lomblen द्वीप समूह). इस प्रकार इलाके के रूप में सूचीबद्ध है "भारत" है। अधिक विशेष रूप से, यह होगा कोरोमंडल तट, द्वारा अनुमान के रसेल (1796).
ब्राउन (1973) का उल्लेख है कि यह भी कर सकते हैं में पाया वियतनाम, लाओस, और पर के इंडोनेशियाई द्वीप सुमात्रा. Ditmars (1937) कथित प्राप्त एक नमूना से सुमात्रा, के रूप में अच्छी तरह से. हालांकि, वितरण की इस प्रजाति में इन्डोनेशियाई द्वीपसमूह है अभी भी जा रहा है elucidated.
रसेल की सांप (Daboia russelii ) है एक प्रजाति का विषैला सांप में परिवार Daboia एक Monotypic प्रतिरूपी Viperidae जीनस का विषैला दुनिया के पुराने वाइपर। एकल सदस्य प्रजातियों, डी russelii, में पाया जाता है Asia एशिया भर में Indian_subcontinent भारतीय उपमहाद्वीपमें ज्यादा के Southeast_Asia दक्षिण पूर्व एशिया, दक्षिणी China चीन और Taiwan ताइवान. प्रजातियों में नामित किया गया था के सम्मान Patrick_Russell_(herpetologist) पैट्रिक रसेल (1726-1805), एक Scotland स्कॉटिश Herpetologist herpetologist जो पहले वर्णित कई के India भारत's सांप, और नाम के जीनस से है Hindi हिंदी शब्द का अर्थ है "निहित है कि छिपा", या "lurker". से अलग किया जा रहा एक सदस्य के Big_Four_(Indian_snakes) चार बड़े सांप भारत में, Daboia भी एक पीढ़ी पैदा करने के लिए जिम्मेदार सबसे Snakebite सर्पदंश की घटनाओं और मौतों के बीच सभी विषैला सांप के खाते में कई कारकों, इस तरह के रूप में उनके व्यापक वितरण, आम तौर पर आक्रामक व्यवहार, और अक्सर घटना में अत्यधिक आबादी वाले क्षेत्रों में।
ଚନ୍ଦନ ବୋଡ଼ା ବା ଚନ୍ଦ୍ର ବୋଡ଼ା ବା ମହାମଣ୍ଡଳ ସାପ (ଇଂରାଜୀ ଭାଷାରେ Russell's viper, ଜୀବବିଜ୍ଞାନ ନାମ Daboia russelii) ହେଉଛି ଭାଇପରିଡାଏ ପରିବାରର ଏକ ବିଷାକ୍ତ ସାପ ।[୧] ଏସିଆ ମହାଦେଶର ଭାରତୀୟ ଉପମହାଦେଶ, ଦକ୍ଷିଣ-ପୂର୍ବ ଏସିଆ, ଚୀନ ଓ ତାଇୱାନରେ ଏହି ସାପ ଦେଖିବାକୁ ମିଳନ୍ତି ।[୨] ଏହି ସାପର ଇଂରାଜୀ ନାମ ସ୍କଟ୍ ସର୍ପବିଜ୍ଞାନୀ ପ୍ୟାଟ୍ରିକ୍ ରସେଲ୍ଙ୍କ (୧୭୨୬-୧୮୦୫) ନାମାନୁସାରେ ରଖାଯାଇଛି ।[୩] ରସେଲ୍ ଭାରତର ବହୁ ସାପଙ୍କ ଜୀବବିଜ୍ଞାନ ବିବରଣୀ ପ୍ରଦାନ କରିଥିଲେ । ଚନ୍ଦନ ବୋଡ଼ା ପ୍ରଜାତିର ହିନ୍ଦୀ ଶବ୍ଦର ଅର୍ଥ ହେଲା – “ଲୁଚି ରହିଥିବା” ବା “ଲୁକ୍କାୟିତ ବିଚରଣ କରୁଥିବା” ।[୪] ଚନ୍ଦନ ବୋଡ଼ାର ଇଂରାଜୀ ଭାଷାରେ ରହିଥିବା ଆଉ ଏକ ସ୍ଥାନୀୟ ନାମ ହେଲା ଚେନ୍ ଭାଇପର୍ (chain viper) ।[୫][୬] ପୂର୍ଣ୍ଣଚନ୍ଦ୍ର ଓଡ଼ିଆ ଭାଷାକୋଷ ଅନୁସାରେ ହଳଦିଆ ଦେହରେ ତିନି ଧାଡ଼ି ବଡ଼ ବଡ଼ କଳା ଗୋଲ ଚିହ୍ନଥିବା ଭୟାନକ ବିଷଧର ସାପକୁ ଚନ୍ଦନବୋଡ଼ା ବା ଚନ୍ଦ୍ର ବୋଡ଼ା କୁହାଯାଏ ।[୭] ଦେହରେ ଚନ୍ଦ୍ର ପରି ଚିହ୍ନ ରହିଥିବାରୁ ବଙ୍ଗଳା ଭାଷାରେ ମଧ୍ୟ ଏହି ସାପକୁ ଚନ୍ଦ୍ରୋବୋଡ଼ା ବୋଲି କୁହାଯାଏ । ମରାଠୀ ଭାଷାରେ ଏହି ସାପ ଘୋଣସ ନାମରେ ପରିଚିତ । ଭାରତରେ ଯେଉଁ ୪ ସାପଙ୍କ ଯୋଗୁଁ ସର୍ବାଧିକ ସାପକାମୁଡ଼ା ଦୁର୍ଘଟଣା ଘଟେ, ତା’ ମଧ୍ୟରେ ଚନ୍ଦନ ବୋଡ଼ା ଅନ୍ୟତମ । ନିଜ ଭୌଗୋଳିକ ବ୍ୟାପକତା, ଆକ୍ରମଣାତ୍ମକ ସ୍ୱଭାବ, ଜନବସତିପୂର୍ଣ୍ଣ ଅଞ୍ଚଳରେ ବାସ କରିବା ଇତ୍ୟାଦି କାରଣରୁ ଚନ୍ଦନ ବୋଡ଼ା ଅନ୍ୟ ବିଷାକ୍ତ ସାପଙ୍କ ତୁଳନାରେ ଅଧିକ ମାରାତ୍ମକ ।[୮]
ଇଂରାଜୀ ଭାଷାରେ ବ୍ୟବହୃତ ସାଧାରଣ ନାମ D. russelii ଚନ୍ଦନ ବୋଡ଼ା,[୫][୯][୧୦] ଶିକୁଳି ବୋଡ଼ା,[୬][୧୦] ଭାରତୀୟ ଚନ୍ଦନ ବୋଡ଼ା,[୧୧][୧୨] ସାଧାରଣ ଚନ୍ଦନ ବୋଡ଼ା,[୧୩] ସେଭେନ୍ ପେସର୍,[୧୪] ଶିକୁଳି ସାପ ଓ କଇଁଚି ସାପ ଆଦି ସମସ୍ତ ନାମଙ୍କୁ ବୁଝାଏ ।[୧୫] ପୂର୍ବେ ସିଂହଳୀ ଚନ୍ଦନ ବୋଡ଼ାକୁ ଏକ ଉପପ୍ରଜାତି D. r. pulchella ରୂପେ ବିବେଚିତ କରାଯାଉଥିଲା କିନ୍ତୁ ବର୍ତ୍ତମାନ ଏହାକୁ ଚନ୍ଦନ ବୋଡ଼ା ପ୍ରଜାତି ବୋଲି କୁହାଯାଉଛି ।[୧୩]
ଚନ୍ଦନ ବୋଡ଼ା ସାପ ଭାରତ, ଶ୍ରୀଲଙ୍କା, ବଙ୍ଗଳାଦେଶ, ନେପାଳ, ବ୍ରହ୍ମଦେଶ, ପାକିସ୍ତାନ, ଥାଇଲାଣ୍ଡ, କାମ୍ବୋଡ଼ିଆ, ତିବ୍ବତ, ଚୀନ, ଇଣ୍ଡୋନେସିଆ, ତାଇୱାନ ପ୍ରଭୃତି ଦେଶରେ ଦେଖିବାକୁ ମିଳନ୍ତି । ପ୍ୟାଟ୍ରିକ୍ ରସେଲ୍ଙ୍କ ଲେଖା (୧୭୯୬) ଅନୁସାରେ ଭାରତର କରମଣ୍ଡଳ ଉପକୂଳକୁ ଏହି ସାପଙ୍କ ମୂଳ ବାସସ୍ଥାନ (type locality) ବୋଲି କୁହାଯାଇଛି ।[୨]
୧୯୭୩ ମସିହାରେ ବ୍ରାଉନ୍ଙ୍କ ମତାନୁସାରେ ଭିଏତନାମ, ଲାଓସ ଓ ଇଣ୍ଡୋନେସିଆର ସୁମାତ୍ରା ଦ୍ୱୀପରେ ମଧ୍ୟ ଏହି ସାପ ଦେଖାଯାଉଥିଲେ ।[୧୪] ୧୯୩୭ ମସିହାରେ ରେମଣ୍ଡ୍ ଡିଟ୍ମାର୍ସ୍ ସୁମାତ୍ରାରୁ ଏକ ଚନ୍ଦନ ବୋଡ଼ାର ନମୁନା ପ୍ରାପ୍ତ କରିଥିବାର ଉଲ୍ଲେଖ ରହିଛି ।[୧୬] କିନ୍ତୁ ଇଣ୍ଡୋନେସୀୟ ଦ୍ୱୀପସମୂହରେ ଏହି ସାପର ଉପସ୍ଥିତି ଏପର୍ଯ୍ୟନ୍ତ ଅସ୍ପଷ୍ଟ ରହିଛି ।[୧୭]
ନିଜ ଭୌଗୋଳିକ ବ୍ୟାପ୍ତିରେ ଏହି ସାପଙ୍କ ସଂଖ୍ୟା କେଉଁଠି ଅଧିକ ତ କେଉଁଠି କମ୍ ।[୧୮] ଭାରତର ପଞ୍ଜାବ ଅଞ୍ଚଳ, ପଶ୍ଚିମ ଉପକୂଳ (ବିଶେଷ କରି କର୍ଣ୍ଣାଟକ ରାଜ୍ୟରେ) ଓ ଉତ୍ତର ବଙ୍ଗର ଅପର ପାର୍ଶ୍ୱରେ ଏହି ସାପର ସଂଖ୍ୟା ଅଧିକ । କିନ୍ତୁ ଗାଙ୍ଗେୟ ଉପତ୍ୟକା, ଉତ୍ତର ବଙ୍ଗଳା ଓ ଆସାମ ପ୍ରଭୃତି ଅଞ୍ଚଳରେ ଏମାନଙ୍କ ସଂଖ୍ୟା କମ୍ । ବ୍ରହ୍ମଦେଶରେ ଏହି ସାପ ବହୁମାତ୍ରାରେ ଦେଖାଯାନ୍ତି ।[୧୯] ଥାଇଲ୍ୟାଣ୍ଡର ପଟ୍ଟାୟା ଓ ଅନ୍ୟ ପର୍ଯ୍ୟଟନ ସହରମାନଙ୍କରେ ପ୍ରଚୁର ଖାଦ୍ୟ ମିଳୁଥିବାରୁ ମୂଷାଙ୍କ ସଂଖ୍ୟା ଅଧିକ ଓ ତେଣୁ ମୂଷାଙ୍କ ଶିକାର କରି ଖାଉଥିବା ଚନ୍ଦନ ବୋଡ଼ାଙ୍କ ସଂଖ୍ୟା ମଧ୍ୟ ଅଧିକ ।
ଏକ ନିର୍ଦ୍ଦିଷ୍ଟ ପରିବାସରେ ଚନ୍ଦନ ବୋଡ଼ା ଅଧିକ ମାତ୍ରାରେ ରୁହନ୍ତି ବୋଲି କହିହେବ ନାହିଁ । ଏହି ସାପ ବେଶୀ ଘଞ୍ଚ ଜଙ୍ଗଲରେ ରୁହନ୍ତି ନାହିଁ । ଖୋଲା, ଘାସ ପଡ଼ିଆ, ବୁଦାଳିଆ ଜଙ୍ଗଲ, ତୋଟା ବା ବଗିଚା, କୃଷିକ୍ଷେତ୍ର ଆଦି ସ୍ଥାନରେ ଏମାନଙ୍କୁ ଦେଖିବାକୁ ମିଳେ । ତେଣୁ ସମତଳ ଅଞ୍ଚଳ, ଉପକୂଳସ୍ଥ ସମଭୂମି ଓ ପାହାଡ଼ିଆ ଅଞ୍ଚଳରେ ଏମାନେ ସାଧାରଣତଃ ଦେଖାଯାନ୍ତି । ସମୁଦ୍ରପତନରୁ ୨୦୦୦-୩୦୦୦ ଫୁଟ୍ ଉଚ୍ଚତା ପର୍ଯ୍ୟନ୍ତ ଏମାନେ ରହିବା ଦେଖାଯାଇଛି । ସନ୍ତସନ୍ତିଆ ଭୂମି, ବୃଷ୍ଟିବଣ ଓ ଜୁଆରିଆ ଅଞ୍ଚଳରେ ରହିବାକୁ ଏମାନେ ପସନ୍ଦ କରନ୍ତି ନାହିଁ ।[୫]
ଗାଁ-ସହର ପରି ଜନବସତି ଅଞ୍ଚଳରେ ମୂଷା ଅଧିକ ରହୁଥିବାରୁ ସେହି ଅଞ୍ଚଳରେ ଅଧିକାଂଶ ସମୟରେ ଚନ୍ଦନ ବୋଡ଼ା ସାପଙ୍କୁ ଦେଖିବାକୁ ମିଳେ ।[୧୯] ତେଣୁ ଏପରି ଅଞ୍ଚଳରେ ଘର ବାହାରେ କାମ କରୁଥିବା ଲୋକ ଚନ୍ଦନ ବୋଡ଼ା ସଂସ୍ପର୍ଶରେ ଆସିବାର ସମ୍ଭାବନା ଅଧିକ । ନାଗ ଓ ଚିତି ସାପ ପରି ଏମାନେ ଘର ନିକଟକୁ ଚାଲିଆସିବାର ଉଦାହରଣ କମ୍ ।[୫]
ଚନ୍ଦନ ବୋଡ଼ା ସ୍ଥଳଚର ଏବଂ ଏମାନେ ମୁଖ୍ୟତଃ ରାତ୍ରି ସମୟରେ ଅଧିକ ସକ୍ରିୟ ରୁହନ୍ତି । ଥଣ୍ଡା ଦିନରେ ଏମାନେ ନିଜ ବିତରଣ ସମୟ ବଦଳାଇ ଦିବାଚର ପ୍ରକୃତି ମଧ୍ୟ ଦେଖାନ୍ତି ।[୫]
ଚନ୍ଦନ ବୋଡ଼ା ସାପ ଅଳସୁଆ ଓ ଧୀର ଗତିରେ ଗତି କରୁଥାଏ । କିନ୍ତୁ ସେମାନଙ୍କୁ ଅଧିକ ବିରକ୍ତ କଲେ ରାଗିଯାଇ ଆକ୍ରାମକ ହୋଇ ଉଠନ୍ତି । ଅଳ୍ପ ବୟସ୍କ ସାପଗୁଡ଼ିକ କିନ୍ତୁ ଅସ୍ଥିର ଓ ସତର୍କ ପ୍ରକୃତିର ।[୫]
ବିପଦର ଆଶଙ୍କା ପାଇଲେ ଚନ୍ଦନ ବୋଡ଼ା ସାପ ନିଜ ଶରୀରକୁ ଅର୍ଦ୍ଧ ଚନ୍ଦ୍ରାକାର କୁଣ୍ଡଳୀରେ ଗୁଡ଼େଇ ହୋଇଯାଏ । ନିଜ ଶରୀରର ପ୍ରଥମ ଏକ-ତୃତୀୟାଂଶ ଭାଗକୁ ଉଠାଇ ରଖି ହିସ୍-ହିସ୍ ଗର୍ଜନ କରେ । ଏହି ଗର୍ଜନର ଶବ୍ଦ ଅନ୍ୟ ସମସ୍ତ ସାପଙ୍କଠାରୁ ଅଧିକ ବୋଲି କୁହାଯାଏ । କାମୁଡ଼ିବାକୁ ଲମ୍ଫ ମାରିବା ବେଳେ ଏମାନେ ଏତେ ଶକ୍ତି ପ୍ରୟୋଗ କରନ୍ତି ଯେ ଓଜନିଆ ସାପ ମଧ୍ୟ କିଛି ଉଚ୍ଚତା ପର୍ଯ୍ୟନ୍ତ ଡେଇଁ ପଡ଼ିଥାଏ ।[୫] ଚନ୍ଦନ ବୋଡ଼ା ସାପ ବଳିଷ୍ଠ ଓ ଏମାନଙ୍କୁ ଧରିବାକୁ ଚେଷ୍ଟା କଲେ ଆକ୍ରାମକ ପ୍ରତିକ୍ରିୟା ଦେଖାଇଥାନ୍ତି ।[୮] କେବେ ଚନ୍ଦନ ବୋଡ଼ାର କାମୁଡ଼ା କ୍ଷଣମାତ୍ରକ ପାଇଁ ହୋଇପାରେ ତ ଆଉ କେବେ ଏମାନେ ଅନେକ ସେକେଣ୍ଡ୍ ପାଇଁ କାମୁଡ଼ି ଧରି ରଖିଥାନ୍ତି ।[୧୯]
ଯଦିଓ କ୍ରୋଟାଲିନାଏ ପରିବାରର ସାପଙ୍କ ପରି ଚନ୍ଦନ ବୋଡ଼ାଙ୍କର ଉତ୍ତାପ ସମ୍ବେଦନଶୀଳ ଅଙ୍ଗ ନାହିଁ, କିନ୍ତୁ ଭାଇପରିନାଏ ପରିବାରର ଏହି ସଦସ୍ୟ ଉତ୍ତାପର ପ୍ରଭାବରେ ପ୍ରତିକ୍ରିୟା ଦେଖାଇଥାଏ । ଏହି କାରଣରୁ ଏମାନଙ୍କର ତାପ ଚିହ୍ନଟ କରିବାର ଅଙ୍ଗ ଅଛି ବୋଲି ଏକ ଭୁଲ ଧାରଣା ରହିଆସିଛି ।[୨୦][୨୧] ଏମାନଙ୍କ ଶରୀରରେ ତାପ ସମ୍ବେଦନଶୀଳ ଅଙ୍ଗ କେଉଁଠି ଅଛି ତାହା ଅନିର୍ଦ୍ଦିଷ୍ଟ, କିନ୍ତୁ କିଛି ସ୍ନାୟୁର ଶେଷରେ ରହିଥିବା ସୁପର୍ନାଜାଲ୍ ଥଳୀ ତାପ ସମ୍ବେଦନ ଅଙ୍ଗ ପରି କାମ କରିଥାଏ ।[୨୨]
ଚନ୍ଦନ ବୋଡ଼ା ବା ଚନ୍ଦ୍ର ବୋଡ଼ା ବା ମହାମଣ୍ଡଳ ସାପ (ଇଂରାଜୀ ଭାଷାରେ Russell's viper, ଜୀବବିଜ୍ଞାନ ନାମ Daboia russelii) ହେଉଛି ଭାଇପରିଡାଏ ପରିବାରର ଏକ ବିଷାକ୍ତ ସାପ । ଏସିଆ ମହାଦେଶର ଭାରତୀୟ ଉପମହାଦେଶ, ଦକ୍ଷିଣ-ପୂର୍ବ ଏସିଆ, ଚୀନ ଓ ତାଇୱାନରେ ଏହି ସାପ ଦେଖିବାକୁ ମିଳନ୍ତି । ଏହି ସାପର ଇଂରାଜୀ ନାମ ସ୍କଟ୍ ସର୍ପବିଜ୍ଞାନୀ ପ୍ୟାଟ୍ରିକ୍ ରସେଲ୍ଙ୍କ (୧୭୨୬-୧୮୦୫) ନାମାନୁସାରେ ରଖାଯାଇଛି । ରସେଲ୍ ଭାରତର ବହୁ ସାପଙ୍କ ଜୀବବିଜ୍ଞାନ ବିବରଣୀ ପ୍ରଦାନ କରିଥିଲେ । ଚନ୍ଦନ ବୋଡ଼ା ପ୍ରଜାତିର ହିନ୍ଦୀ ଶବ୍ଦର ଅର୍ଥ ହେଲା – “ଲୁଚି ରହିଥିବା” ବା “ଲୁକ୍କାୟିତ ବିଚରଣ କରୁଥିବା” । ଚନ୍ଦନ ବୋଡ଼ାର ଇଂରାଜୀ ଭାଷାରେ ରହିଥିବା ଆଉ ଏକ ସ୍ଥାନୀୟ ନାମ ହେଲା ଚେନ୍ ଭାଇପର୍ (chain viper) । ପୂର୍ଣ୍ଣଚନ୍ଦ୍ର ଓଡ଼ିଆ ଭାଷାକୋଷ ଅନୁସାରେ ହଳଦିଆ ଦେହରେ ତିନି ଧାଡ଼ି ବଡ଼ ବଡ଼ କଳା ଗୋଲ ଚିହ୍ନଥିବା ଭୟାନକ ବିଷଧର ସାପକୁ ଚନ୍ଦନବୋଡ଼ା ବା ଚନ୍ଦ୍ର ବୋଡ଼ା କୁହାଯାଏ । ଦେହରେ ଚନ୍ଦ୍ର ପରି ଚିହ୍ନ ରହିଥିବାରୁ ବଙ୍ଗଳା ଭାଷାରେ ମଧ୍ୟ ଏହି ସାପକୁ ଚନ୍ଦ୍ରୋବୋଡ଼ା ବୋଲି କୁହାଯାଏ । ମରାଠୀ ଭାଷାରେ ଏହି ସାପ ଘୋଣସ ନାମରେ ପରିଚିତ । ଭାରତରେ ଯେଉଁ ୪ ସାପଙ୍କ ଯୋଗୁଁ ସର୍ବାଧିକ ସାପକାମୁଡ଼ା ଦୁର୍ଘଟଣା ଘଟେ, ତା’ ମଧ୍ୟରେ ଚନ୍ଦନ ବୋଡ଼ା ଅନ୍ୟତମ । ନିଜ ଭୌଗୋଳିକ ବ୍ୟାପକତା, ଆକ୍ରମଣାତ୍ମକ ସ୍ୱଭାବ, ଜନବସତିପୂର୍ଣ୍ଣ ଅଞ୍ଚଳରେ ବାସ କରିବା ଇତ୍ୟାଦି କାରଣରୁ ଚନ୍ଦନ ବୋଡ଼ା ଅନ୍ୟ ବିଷାକ୍ତ ସାପଙ୍କ ତୁଳନାରେ ଅଧିକ ମାରାତ୍ମକ ।
கண்ணாடி விரியன் (
ஒலிப்பு ) (Russel's Viper, Daboia russelii) என்பது நச்சுத் தன்மை கொண்ட பாம்பு. இவை ஆசியாவில் குறிப்பாக இந்தியத் துணைக்கண்டம் முழுவதிலும், தென்கிழக்காசியா, சீனாவின் தெற்குப் பகுதி, தாய்வான் ஆகிய நாடுகளில் காணப்படுகின்றன[1]. இது பெரும் நான்கு எனப்படும் நான்கு பாம்புகளில் ஒன்று. இந்தியாவில் பாம்புக்கடியினால் ஏற்படும் உயிரிழப்புகளுக்கு ஏறக்குறைய இவை நான்கே காரணம்[2].
விரியன் பாம்பின் நச்சு குருதிச் சிதைப்பானாகும். ஆகவே மருத்துவர்கள் இரத்தம் உறையும் நேரம் மற்றும் இரத்தம் வழியும் நேரம் ஆகியவற்றை மணிக்கொரு முறைச் சோதிப்பர்.
கண்ணாடி விரியன் (ஒலிப்பு ) (Russel's Viper, Daboia russelii) என்பது நச்சுத் தன்மை கொண்ட பாம்பு. இவை ஆசியாவில் குறிப்பாக இந்தியத் துணைக்கண்டம் முழுவதிலும், தென்கிழக்காசியா, சீனாவின் தெற்குப் பகுதி, தாய்வான் ஆகிய நாடுகளில் காணப்படுகின்றன. இது பெரும் நான்கு எனப்படும் நான்கு பாம்புகளில் ஒன்று. இந்தியாவில் பாம்புக்கடியினால் ஏற்படும் உயிரிழப்புகளுக்கு ஏறக்குறைய இவை நான்கே காரணம்.
రక్తపింజరి పాము జాతులు చాలా ఆగ్నేయాసియా ప్రాంతాలు, భారత ఉపఖండం అంతటా, ఆసియాలో దక్షిణ చైనా నుండి టైవాన్ వరకు విస్తరించి ఉన్నాయి. దీనిని కాటుక రేకుల పాము అని కూడా పిలుస్తారు. దాని ప్రకోప స్వభావం కారణంగా ఏ ఇతర విషసర్పాల కంటే కూడా ఎక్కువ మానవ మరణాలకు బాధ్యత వహిస్తుంది. దాదాపు అన్ని భారతీయ పాముకాటు మరణాలకు కారణమైన నాలుగు విష స్రావము గల సర్పాలలో ఇదీ ఒకటి.
ఈ పాము గరిష్ఠంగా 166 సెం.మీ. (5.5 అడుగులు) పొడవు పెరుగుతుంది. అయితే సగటు పొడవు, ప్రధాన భూభాగంలో 120 గురించి సెం.మీ. (4 అడుగులు). అనేక ఇతర విష సర్పాలు కంటే ఇది మరింత సన్నగా నిర్మించబడింది.దిత్మార్స్ (1937) "సరైన పరిమాణపు వయోజన నమూనాను" కొరకు ఈ క్రింది కొలతలు నివేదించారు.
తల చదునుగా, త్రిభుజాకారంగా మెడ నుండి వైవిధ్యంగా ఉంటుంది.జంతువుల ముట్టె భాగము సమీప, పెరిగింది, మొద్దుబారిన ఉంది. నాసికా రంధ్రాల పెద్ద, సింగిల్ నాసికా ఎత్తున మధ్యలో, పెద్ద ఉన్నాయి. నాసికా దిగువ అంచు nasorostral తాకినప్పుడు. supranasal బలమైన చంద్రవంక ఆకారంలో, nasorostral anteriorly నుండి నాసికా విడదీస్తుంది. ఇది ఎక్కువగాగా rostral. విస్తృత [2]
తల కిరీటం సక్రమంగా, గట్టిగా విచ్ఛిన్న ప్రమాణాలతో కప్పబడి ఉంటుంది. supraocular ప్రమాణాల సంకుచితమైన, సింగిల్, తల మీదుగా 6-9 ప్రమాణాల ద్వారా వేరు. కళ్ళు పసుపు లేదా బంగారుతో flecked, పెద్దవి, ప్రతి 10-15 circumorbital ప్రమాణాల చుట్టుముట్టి ఉంది. గణనీయంగా పెద్ద 4, 5 వీటిలో 10-12 supralabials ఉన్నాయి. కంటి suboculars యొక్క 3-4 వరుసలు ద్వారా supralabials నుండి వేరుచేయబడి ఉంటుంది. గడ్డం షీల్డ్స్, ముఖ్యంగా విస్తరించి ఉన్న ముందు జత రెండు జతల ఉన్నాయి. రెండు పై దవడ యొక్క ఎముకలు ఒక సమయంలో కోరలు అత్యంత ఐదు లేదా ఆరు జతల వద్ద కనీసం రెండు, మద్దతు:.. మొదటి ఉత్సాహంగా ఉన్నాయి, మిగిలిన స్థానంలో [2] కోరలు సగటు స్పెసిమెన్ లో 16 mm పొడవు సాధించడానికి [13]
శరీర, స్థూపాకారకు సమీప ఇది అడ్డుకోత బలిసిన ఉంది. మెదడు ప్రమాణాల గట్టిగా keeled ఉంటాయి; మాత్రమే తక్కువ వరుస నునుపుగా ఉంటుంది. మధ్య శరీరం, మెదడు ప్రమాణాల సంఖ్య 27-33. ముందువైపు ప్రమాణాల సంఖ్య 153-180. ఆసన ప్లేట్ విభజించబడింది లేదు. తోక చిన్నదిగా ఉంది - మొత్తం శరీరం పొడవు ఇది 14% -. జత subcaudals 41-68 అంకెలతో [2]
రంగు నమూనా దాని శరీరం యొక్క పొడవు అమలు ఆ ముదురు గోధుమ రంగు మచ్చలు మూడు సిరీస్ తో లోతైన పసుపు, తాన్ లేదా గోధుమ గ్రౌండ్ రంగు, ఉంటుంది. ఈ మచ్చలు ప్రతి దాని చుట్టూ ఒక నల్లని రింగ్ ఉంది, ఇది బాహ్య సరిహద్దు తెలుపు లేదా పసుపు ఒక చట్రంతో తీవ్రమైంది ఉంది. మెదడు మచ్చలు, సైడ్ మచ్చలు విభజించు మే అయితే ఇది సాధారణంగా సంఖ్య 23-30, కలిసి పెరగడం ఉండవచ్చు. తల ఒక pinkish, సాల్మన్ లేదా బ్రౌనిష్ వి లేదా జంతువుల ముట్టె భాగము వైపు ఒక శిఖరాగ్ర ఆ రూపాలు X నమూనా కలిసి, ప్రత్యేకమైన కృష్ణ అతుకులు, ప్రతి ఆలయం న ఒక ఒక జత చేసింది. కంటి వెనుక, గులాబీ లేదా బ్ తెలుపు అంశాన్ని ఒక చీకటి పరంపర, ఉంది. ఉదరకుహరము తరచుగా కృష్ణ మచ్చలు ఒక సక్రమంగా పరిక్షేపం తో,, తెలుపు whitish, పసుపు లేదా pinkish ఉంది.
Found in Pakistan, India, Sri Lanka, Bangladesh, Nepal, Myanmar, Thailand, Cambodia, China (Guangxi, Guangdong), Taiwan and Indonesia (Endeh, Flores, east Java, Komodo, Lomblen Islands). The type locality is listed as "India". More specifically, this would be the Coromandel Coast, by inference of Russell (1796).[14]
Brown (1973) mentions that it can also found in Vietnam, Laos and on the Indonesian island of Sumatra.[7] Ditmars (1937) reportedly received a specimen from Sumatra as well.[13] However, the distribution of this species in the Indonesian archipelago is still being elucidated.[15]
Within its range it can be very common in some areas, but scarce in others.[16] In India, is abundant in Punjab, very common along the West Coast and its hills, in southern India and up to Bengal. It is uncommon to rare in the Ganga valley, northern Bengal and Assam. It is prevalent in Myanmar.[10]
It is not restricted to any particular habitat, but does tend to avoid dense forests. The snake is mostly found in open, grassy or bushy areas, but may also be found in second growth forests (scrub jungles), on forested plantations and farmland. They are most common in plains, coastal lowlands and hills of suitable habitat. Generally not found at altitude, but has been reported as far up as 2300–3000 m. Humid environments, such as marshes, swamps and rain forests, are avoided.[1]
This species is often found in highly urbanized areas and settlements in the countryside, the attraction being the rodents commensal with man.[10] As a result, those working outside in these areas are most at risk of being bitten. It should be noted, however, that D. russelii does not associate as closely with human habitation as Naja and Bungarus (cobras and kraits).[1]
Terrestrial and active primarily as a nocturnal forager. However, during cool weather it will alter its behavior and become more active during the day.[1]
Adults are reported to be persistently slow and sluggish unless pushed beyond a certain limit, after which they become fierce and aggressive. Juveniles, on the other hand, are generally more active and will bite with minimal provocation.[1]
When threatened they form a series of S-loops, raise the first third of the body and produce a hiss that is supposedly louder than that of any other snake. When striking from this position, they can exert so much force that even a large individual can lift most of its body off the ground in the process.[1] These are difficult snakes to handle: they are strong and agile and react violently to being picked up.[17] The bite may be a snap, or, they may hang on for many seconds.[10]
Although this genus does not have the heat-sensitive pit organs common to the Crotalinae, it is one of a number of viperines that are apparently able to react to thermal cues, further supporting the notion that they too possess a heat-sensitive organ.[18][19] The identity of this sensor is not certain, but the nerve endings in the supranasal sac of these snakes resemble those found in other heat-sensitive organs.[20]
It feeds primarily on rodents, especially murid species. However, they will eat just about anything, including rats, mice, shrews, squirrels, land crabs, scorpions and other arthropods. Juveniles are crepuscular, feeding on lizards and foraging actively. As they grow and become adults, they begin to specialize in rodents. Indeed, the presence of rodents is the main reason they are attracted to human habitation.[1]
Juveniles are known to be cannibalistic.[10]
This species is ovoviviparous.[16] Mating generally occurs early in the year, although gravid females may be found at any time. The gestation period is more than six months. Young are produced from May to November, but mostly in June and July. It is a prolific breeder. Litters of 20–40 are common,[1] although there may be fewer offspring and as little as one.[10] The reported maximum is 65 in a single litter. At birth, juveniles are 215–260 mm in length. The minimum length for a gravid female is about 100 cm. It seems that sexual maturity is achieved in 2–3 years. In one case, it took a specimen nearly 4.5 hours to produce 11 young.[1]
These snakes do extremely well in captivity, requiring only a water dish and a hide box. Juveniles feed readily on pinky mice, while the adults will take rats, mice and birds.[1] However, many adults do not feed, with one having refused all food for five months.[10] Breeding is not a problem either. On the other hand, they do make quite dangerous captives.[1] When handled, specimens have been known to use their long, curved fangs to bite right through their lower jaw and into the thumb of the person holding them.[17]
The amount of venom produced by individual specimens is considerable. Reported venom yields for adult specimens range from 130–250 mg to 150–250 mg to 21–268 mg. For 13 juveniles with an average length of 79 cm, the average venom yield was 8–79 mg (mean 45 mg).[1]
The LD50 in mice, which is used as a general indicator of snake venom toxicity, is as follows: 0.08–0.31 μg/g intravenous, 0.40 μg/kg intraperitoneal, 4.75 mg/kg subcutaneous. For most humans a lethal dose is 40–70 mg. In general, the toxicity depends on a combination of five different venom fractions, each of which is less toxic when tested separately. Venom toxicity also varies within populations and over time.[1]
Envenomation symptoms begin with pain at the site of the bite, immediately followed by swelling of the affected extremity. Bleeding is a common symptom, especially from the gums, and sputum may show signs of blood within 20 minutes post-bite. There is a drop in blood pressure and the heart rate falls. Blistering occurs at the site of the bite, developing along the affected limb in severe cases. Necrosis is usually superficial and limited to the muscles near the bite, but may be severe in extreme cases. Vomiting and facial swelling occurs in about one-third of all cases.[1]
Severe pain may last for 2–4 weeks. Locally, it may persist depending on the level of tissue damage. Often, local swelling peaks within 48–72 hours, involving both the affected limb and the trunk. If swelling up to the trunk occurs within 1–2 hours, massive envenomation is likely. Discoloration may occur throughout the swollen area as red blood cells and plasma leak into muscle tissue.[8] Death from septicaemia, respiratory or cardiac failure may occur 1 to 14 days post-bite or even later.[10]
Because this venom is so effective at inducing thrombosis, it has been incorporated into an in vitro diagnostic test for blood clotting that is widely used in hospital laboratories. This test is often referred to as Dilute Russell's viper venom time (dRVVT). The coagulant in the venom directly activates factor X, which turns prothrombin into thrombin in the presence of factor V and phospholipid. The venom is diluted to give a clotting time of 23 to 27 seconds and the phospholipid is reduced to make the test extremely sensitive to phospholipid. The dRVVT test is more sensitive than the aPTT test for the detection of lupus anticoagulant (an autoimmune disorder), because it is not influenced by deficiencies in clotting factors VIII, IX or XI.[21]
In India, the Haffkine Institute prepares a polyvalent antivenin that is used to treat bites from this species.[10]
Using morphological and mitochondrial DNA data, Thorpe et al. (2007)[24] provided evidence that the eastern subspecies should be considered a separate species, Daboia siamensis
A number of other subspecies may be encountered in literature,[1] including:
The correct spelling of the species, D. russelii has been, and still is, a matter of debate. Shaw & Nodder (1797), in their account of the species Coluber russelii, named it after Dr. Patrick Russell, but apparently misspelled his name, using only one "L" instead of two. Russell (1727–1805) was the author of An Account of Indian Serpents (1796) and A Continuation of an Account of Indian Serpents (1801). McDiarmid et al. (1999) are among those who favor the original misspelled spelling, citing Article 32c (ii) of the International Code of Zoological Nomenclature. Others, such as Zhao and Adler (1993) favor russellii.[14]
In the future, more species may be added to Daboia. Obst (1983) reviewed the genus and suggested that it be extended to include Macrovipera lebetina, Vipera palaestinae and V. xanthina. Groombridge (1980, 1986) united V. palaestinae and Daboia as a clade based on a number of shared apomorphies, including snout shape and head color pattern. Lenk et al. (2001) found support for this idea based on molecular evidence, suggesting that Daboia not only include V. palaestinae, but also M. mauritanica and M. deserti.[1]
Some herpetologists believe that, because D. russelii is so successful as a species and has such a fearful reputation within its natural environment, another snake has even come to mimic its appearance. Superficially, the rough-scaled sand boa, Gongylophis conicus, has a color pattern that often looks a lot like that of D. russelii, even though it is completely harmless.[1][13]
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Russell's viper (Daboia russelii) is a venomous snake in the family Viperidae native to the Indian subcontinent and one of the big four snakes in India. It was described in 1797 by George Shaw and Frederick Polydore Nodder, and named after Patrick Russell, who wrote about it in his 1796 work An account of Indian serpents, collected on the coast of Coromandel.
English naturalist George Shaw—with illustrator Frederick Polydore Nodder—in The Naturalist's Miscellany: Or, Coloured Figures Of Natural Objects; Drawn and Described Immediately From Nature formally described the species in 1797 as Coluber russelii, from a specimen presented to the British Museum by Scottish herpetologist Patrick Russell.[1] Russell had written of the species in his 1796 work An account of Indian serpents, collected on the coast of Coromandel, confirming its highly venomous nature by experimenting on chickens and dogs. He added the native people called it katuka retula poda.[2]
Analysis of morphological and mitochondrial DNA data shows that the eastern subspecies of D. russelii should be considered a separate species, Daboia siamensis.[3]
A number of other subspecies may be encountered in literature,[4] including:
The correct spelling of the species, D. russelii, has been, and still is, a matter of debate. Shaw and Nodder (1797), in their account of the species Coluber russelii, named it after Patrick Russell, but apparently misspelled his name, using only one "L" instead of two. Russell (1727–1805) was the author of An Account of Indian Serpents (1796) and A Continuation of an Account of Indian Serpents (1801). McDiarmid et al. (1999) are among those who favor the original misspelling, citing Article 32c (ii) of the International Code of Zoological Nomenclature. Others, such as Zhao and Adler (1993) favor russellii.[5]
The species is named after Patrick Russell (1726–1805),[6] a Scottish herpetologist who first described many of India's snakes, and the name of the genus is from the Hindi word meaning "that lies hid", or "the lurker".[7]
In English, common names of D. russelii include Russell's viper,[4][8][9][10] chain viper,[8][10] Indian Russell's viper,[11][12] common Russell's viper,[13] seven pacer,[14] chain snake, and scissors snake.[15]
The head is flattened, triangular, and distinct from the neck. The snout is blunt, rounded, and raised. The nostrils are large, each in the middle of a large, single nasal scale. The lower edge of the nasal scale touches the nasorostral scale. The supranasal scale has a strong crescent shape and separates the nasal from the nasorostral scale anteriorly. The rostral scale is as broad as it is high.[4]
The crown of the head is covered with irregular, strongly fragmented scales. The supraocular scales are narrow, single, and separated by six to nine scales across the head. The eyes are large, flecked with yellow or gold, and surrounded by 10–15 circumorbital scales. The snake has 10–12 supralabials, the fourth and fifth of which are significantly larger. The eye is separated from the supralabials by three or four rows of suboculars. Of the two pairs of chin shields, the front pair is notably enlarged. The two maxillary bones support at least two and at the most five or six pairs of fangs at a time: the first are active and the rest replacements.[4] The fangs attain a length of 16.5 mm (0.65 in) in the average specimen.[16]
The body is stout, the cross-section of which is rounded to circular. The dorsal scales are strongly keeled; only the lowest row is smooth. Mid-body, the dorsal scales number 27–33. The ventral scales number 153–180. The anal plate is not divided. The tail is short—about 14% of the total length—with the paired subcaudals numbering 41–68.[4]
Dorsally, the color pattern consists of a deep yellow, tan, or brown ground color, with three series of dark brown spots that run the length of the body. Each of these spots has a black ring around it, the outer border of which is intensified with a rim of white or yellow. The dorsal spots, which usually number 23–30, may grow together, while the side spots may break apart. The head has a pair of distinct dark patches, one on each temple, together with a pinkish, salmon, or brownish V or X marking that forms an apex towards the snout. Behind the eye is a dark streak, outlined in white, pink, or buff. The venter is white, whitish, yellowish, or pinkish, often with an irregular scattering of dark spots.[4]
Russell's viper grows to a maximum body and tail length of 166 cm (65 in) and averages about 120 cm (47 in) in mainland Asia. In islands, it is slightly shorter on average.[4] It is more slender than most vipers.[17] The following dimensions for a "fair-sized adult specimen" were reported in 1937:[18]
Russell's viper is found in India, Sri Lanka, Bangladesh, Nepal, and Pakistan. Populations from South-East Asia previously assigned to this species are now considered to be part of a different species, Daboia siamensis.[3] The type locality is listed as "India". More specifically, this would be the Coromandel Coast, by inference of Russell (1796).[5]
Within its range, it can be common in some areas, but scarce in others.[17] In India, is abundant in Punjab, very common along the West Coast and its hills, in southern India especially in the state of Karnataka and north to Bengal. It is uncommon to rare in the Ganges valley, northern Bengal, and Assam.
Russell's viper is not restricted to any particular habitat, but does tend to avoid dense forests. The snake is mostly found in open, grassy or bushy areas, but may also be found in second growth forests (scrub jungles), on forested plantations and farmland. It is most common in plains, coastal lowlands, and hills of suitable habitat. Generally, it is not found at altitude, but has been reported as far up as 2300–3000 m (7,500–9,800 ft). Humid environments, such as marshes, swamps, and rain forests, are avoided.[4]
This species is often found in highly urbanized areas and settlements in the countryside, the attraction being the rodents commensal with man.[16] As a result, those working outside in these areas are most at risk of being bitten. D. russelii does not associate as closely with human habitation as Naja and Bungarus species (cobras and kraits).[4]
Russell's viper is terrestrial and active primarily as a nocturnal forager. However, during cool weather, it alters its behavior and becomes more active during the day.[4] Adults are reported to be slow and sluggish unless pushed beyond a certain limit, after which they can become very aggressive. Juveniles, though, are generally more nervous.[4] When threatened, they form a series of S-loops, raise the first third of the body, and produce a hiss that is supposedly louder than that of any other snake. When striking from this position, they can exert so much force that even a large individual can lift most of its body off the ground in the process.[4] These snakes are strong and may react violently to being picked up.[19] The bite may be a snap, or they may hang on for many seconds.[16]
Although this genus does not have the heat-sensitive pit organs common to the Crotalinae, it is one of a number of viperines that are apparently able to react to thermal cues, further supporting the notion that they, too, possess a heat-sensitive organ.[20][21] The identity of this sensor is not certain, but the nerve endings in the supranasal sac of these snakes resemble those found in other heat-sensitive organs.[22]
Russell's viper is ovoviviparous.[17] Mating generally occurs early in the year, although pregnant females may be found at any time. The gestation period is more than six months. Young are produced from May to November, but mostly in June and July. It is a prolific breeder. Litters of 20–40 are common,[4] although fewer offspring may occur, as few as one.[16] The reported maximum is 75[23] in a single litter. At birth, juveniles are 215–260 mm (8.5–10.2 in) in total length. The minimum total length for a gravid female is about 100 cm (39 in). It seems that sexual maturity is achieved in 2–3 years. In one case, it took a specimen nearly 4.5 hours to give birth to 11 young.[4]
Russell's viper feeds primarily on rodents, although especially it will also eat small reptiles, land crabs, scorpions, and other arthropods. Juveniles are crepuscular, feeding on lizards and foraging actively. As they grow and become adults, they begin to specialize in rodents. Indeed, the presence of rodents and lizards is the main reason they are attracted to human habitation.[4] Juveniles are known to be cannibalistic.[16]
Some herpetologists believe, because D. russelii is so successful as a species and has such a fearful reputation within its natural environment, another snake has come to mimic its appearance. Superficially, the rough-scaled sand boa Eryx conicus has a color pattern that often looks like that of D. russelii, though it is completely harmless.[4][18]
Venom of this species is delivered by means of solenoglyphous dentition.[24] The quantity of venom produced by individual specimens of D. russelii is considerable. Venom yields for adult specimens have been reported as 130–250 mg, 150–250 mg, and 21–268 mg. For 13 juveniles with an average total length of 79 cm (31 in), the venom yield ranged from 8 to 79 mg (mean 45 mg).[4]
The LD50 in mice, which is used as a possible indicator of snake venom toxicity, is: 0.133 mg/kg intravenous,[25] 0.40 mg/kg intraperitoneal,[26] about 0.75 mg/kg subcutaneous.[27] For most humans, a lethal dose is about 40–70 mg, well within the amount that can be delivered in one bite. In general, the toxicity depends on a combination of five different venom fractions, each of which is less toxic when tested separately. Venom toxicity and bite symptoms in humans vary within different populations and over time.[4] In another study, Meier and Theakston reported that the lethality of venom of Russell viper varies with change in route of injection, as their results predicts the LD50 of 0.4 mg/kg through intraperitoneal (I.P) route, 0.75 mg/kg/subcutaneous (S.C) route and 0.3 mg/kg through intravenous (I.V) route.[28]
Envenomation symptoms begin with pain at the site of the bite, immediately followed by swelling of the affected extremity. Bleeding is a common symptom, especially from the gums and in the urine, and sputum may show signs of blood within 20 minutes after the bite. The blood pressure drops, and the heart rate falls. Blistering occurs at the site of the bite, developing along the affected limb in severe cases. Necrosis is usually superficial and limited to the muscles near the bite, but may be severe in extreme cases. Vomiting and facial swelling occur in about one-third of all cases.[4] Kidney failure (renal failure) also occurs in approximately 25–30 percent of untreated bites. Severe disseminated intravascular coagulation also can occur in severe envenomations. Early medical treatment and early access to antivenom can prevent and drastically reduce the chance of developing the severe/potentially lethal complications.
Severe pain may last for 2–4 weeks. It may persist locally, depending on the level of tissue damage. Often, local swelling peaks within 48–72 hours, involving both the affected limb and the trunk. If swelling up to the trunk occurs within 1–2 hours, envenomation is likely to have been massive. Discoloration may occur throughout the swollen area as red blood cells and plasma leak into muscle tissue.[15] Death from septicaemia or kidney, respiratory, or cardiac failure may ensue 1 to 14 days after the bite, or sometimes later.[16]
A study in The Lancet showed that out of a sample of people who survived bites by D. russelii, 29% suffered severe damage to their pituitary glands, which later caused hypopituitarism.[29] Other scientific studies support the hypothesis that D. russelii bites can cause hypopituitarism.[30][31]
In India, the Haffkine Institute prepares a polyvalent antivenom that is used to treat bites from this species.[16] In late 2016 a new antivenom had been developed by the Costa Rican Clodomiro Picado Institute, and clinical trials were started in Sri Lanka.[32]
Because this venom is so effective at inducing thrombosis, it has been incorporated into an in vitro diagnostic test for blood clotting that is widely used in hospital laboratories. This test is often referred to as dilute Russell's viper venom time (dRVVT). The coagulant in the venom directly activates factor X, which turns prothrombin into thrombin in the presence of factor V and phospholipid. The venom is diluted to give a clotting time of 23 to 27 seconds and the phospholipid is reduced to make the test extremely sensitive to phospholipid. The dRVVT test is more sensitive than the aPTT test for the detection of lupus anticoagulant (an autoimmune disorder), because it is not influenced by deficiencies in clotting factors VIII, IX or XI.[33]
Russell's viper (Daboia russelli) in a sensing moment Russell's viper (Daboia russelii) is a venomous snake in the family Viperidae native to the Indian subcontinent and one of the big four snakes in India. It was described in 1797 by George Shaw and Frederick Polydore Nodder, and named after Patrick Russell, who wrote about it in his 1796 work An account of Indian serpents, collected on the coast of Coromandel.
La víbora de Russell (Daboia russelii),[2][3] también denominada víbora de cadena,[4][5] víbora india de Russell,[6][7] o serpiente de las tijeras,[8] es una especie de serpiente venenosa vipérida del Viejo Mundo, que vive en Asia a lo largo del subcontinente indio; la antigua subespecie D. russelii siamensis se reparte por la mayor parte de Asia Sudoriental, China meridional y Taiwán.[1] Daboia era, hasta hace poco, un género monotípico.[9] Es miembro del grupo de las cuatro grandes serpientes venenosas de la India.[10] Esta especie es responsable de la mayor parte de casos de mordeduras y muertes en el mundo debido a su frecuente presencia en lugares poblados por humanos. Su nombre le fue dado en honor a Patrick Russell (1726–1805), un herpetólogo escocés, el primero en describir muchas de las serpientes de la India; su nombre genérico, daboia, viene del hindi y significa "esa cosa oculta" o "la que acecha."[11]
Esta serpiente alcanza una longitud máxima de 166 cm (5.5 ft) y el promedio es de alrededor de 120 cm (4 ft) en poblaciones continentales de Asia, aunque las poblaciones insulares no alcanzan ese tamaño.[2] Es más delgada que la mayor parte de las otras vipéridas.[12] Ditmars (1937) reportaron las siguientes dimensiones para "especímenes adultos de tamaño regular":[13]
La cabeza es aplanada, triangular, y diferenciada del cuello. El hocico es embotado, doblado y levantado. Las fosas nasales son grandes, en medio de una escama nasal única y grande. El borde inferior de la nasal toca la nasorostral. La supranasal tiene una fuerte forma creciente y separa la nasal de la nasorostral anteriormente. La escama rostral es tan amplia como alta.[2]
La corona de la cabeza está cubierta de escamas irregulares, fuertemente fragmentadas. Las escamas supraoculares son angostas, solas, y separadas por 6–9 escamas a través de la cabeza. Los ojos son amplios, manchados con amarillo o dorado, y cada uno está rodeado por 10–15 escamas circumorbitales. Hay 10–12 supralabiales, de las cuales, la cuarta y quinta son significativamente más amplias. El ojo está separado de las supralabiales por 3–4 filas de suboculares. Hay dos pares de escudos de barbilla, el par frontal notablemente ampliado. Los dos huesos maxilares soportan, al menos, dos y la mayor parte cinco o seis pares de colmillos a la vez: los primeros son activos y el resto de reemplazo.[2] Los colmillos alcanzan una longitud de 16 mm en el espécimen promedio.[14]
El cuerpo es fuerte, la sección de un corte transversal es redondeado a cilíndrico. Las escamas dorsales son fuertemente aquilladas; sólo la fila inferior es lisa. Medio cuerpo, 27-33 escamas dorsales. Las escamas ventrales son de 153-180. El plato anal no está dividido. La cola es corta — aproximadamente el 14 % de la longitud de total del cuerpo— con escamas subcaudales de 41–68.[2]
La cantidad de veneno producido por un espécimen individual es considerable. La producción de veneno reportada para especímenes adultos está en un rango de 130–250 mg a 150–250 mg a 210–268 mg. Para 13 juveniles con una longitud promedio de 79 cm, la producción de veneno fue de 8–79 mg (media 45 mg).[2]
La DL50 en ratones, la que se usa como un indicador general de la toxicidad del veneno de serpiente, es como sigue: 0,08–0,31 μg/g intravenoso, 0,40 μg/kg intraperitoneal, 0,75-1,6 mg/kg subcutáneo.[15] Para la mayoría de los humanos, una dosis letal es de aproximadamente 40–70 mg. En general, la toxicidad depende de una combinación de cinco diferentes fracciones del veneno, cada una de las cuales es menos tóxica al ser probada separadamente. La toxicidad del veneno y los síntomas de la mordedura en humanos varían dentro de diferentes poblaciones y a lo largo del tiempo.[2]
Los síntomas de envenenamiento comienzan con dolor en el sitio de la mordedura, seguido en forma inmediata por la hinchazón de la extremidad afectada. La hemorragia es un síntoma común, especialmente en las encías y la orina, y el esputo puede mostrar signos de sangre dentro de los 20 minutos posteriores a la mordedura. Hay un descenso en la presión sanguínea y caída de la frecuencia cardíaca. Se producen ampollas en el sitio de la mordedura, que se desarrollan a lo largo del miembro afectado en casos severos. La necrosis es por lo general superficial y limitada a los músculos cerca de la mordedura, pero puede ser severa en casos extremos. Los vómitos y la hinchazón facial ocurren en aproximadamente una tercera parte de los casos.[2] Puede presentarse un fallo renal en, aproximadamente, el 25-30 % de las mordeduras no tratadas.
Coagulación intravascular diseminada severa también puede ocurrir en envenenamientos severos. El tratamiento médico inmediato y el inmediato acceso al antisuero pueden prevenir y reducir drásticamente las posibilidades de desarrollar complicaciones severas/potencialmente letales.
El dolor severo puede durar de 2 a 4 semanas. Localmente, puede persistir dependiendo del nivel de daño tisular. A menudo, el pico de inflamación local dentro de las 48 a 72 horas, involucra el miembro afectado y el tronco. Si se presenta la hinchazón hasta el tronco dentro de 1 a 2 horas, es probable el envenenamiento masivo. Puede ocurrir decoloración a lo largo del área inflamada cuando glóbulos rojos y plasma abandonan el tejido muscular.[8] La muerte por septicemia, fallo renal, respiratorio o cardíaco puede ocurrir 1 a 14 días con posterioridad a la mordedura o aún más tarde.[14]
Debido a que este veneno es efectivo para inducir trombocitopenia, ha sido incorporado en una prueba para diagnóstico in vitro para coagulación sanguínea que es ampliamente usada en laboratorios de hospitales. Este test es, a menudo, conocido como ensayo del veneno de la víbora de Rusell diluido (dRVVT). El coagulante en el veneno directamente activa el factor X, que cambia protrombina en trombina en la presencia del factor V y fosfolípidos. El veneno es diluido para dar un tiempo de coagulación de 23 a 27 segundos y el fosfolípido es reducido para hacer un test extremadamente sensible a fosfolípido. El test dRVVT es más sensible que el test aPTT para la detección de anticoagulante lúpico (una enfermedad autoinmune), debido a que no es influido por deficiencias en los factores de coagulación VIII, IX o XI.[16]
Esta especie es ovovivípara.[12] El apareamiento ocurre generalmente a comienzos del año, aunque se pueden encontrar hembras grávidas en cualquier época. El período de gestación es de más de seis meses. Los juveniles son producidos de mayo a noviembre, pero mayoritariamente en junio y julio. Son criadores prolíficos. Camadas de 20–40 animales son comunes,[2] aunque puede haber descendencia menor y a veces llegar a una sola cría.[14] El máximo reportado es 65 en una sola camada. Al nacimiento, las crías tienen una longitud de 215–260 mm. La menor longitud para una hembra grávida es de aproximadamente 100 cm. Parece ser que la madurez sexual se alcanza de los 2 a 3 años. En un caso, le llevó a un espécimen casi 4 horas y media parir 11 crías.[2]
La víbora de Russell (Daboia russelii), también denominada víbora de cadena, víbora india de Russell, o serpiente de las tijeras, es una especie de serpiente venenosa vipérida del Viejo Mundo, que vive en Asia a lo largo del subcontinente indio; la antigua subespecie D. russelii siamensis se reparte por la mayor parte de Asia Sudoriental, China meridional y Taiwán. Daboia era, hasta hace poco, un género monotípico. Es miembro del grupo de las cuatro grandes serpientes venenosas de la India. Esta especie es responsable de la mayor parte de casos de mordeduras y muertes en el mundo debido a su frecuente presencia en lugares poblados por humanos. Su nombre le fue dado en honor a Patrick Russell (1726–1805), un herpetólogo escocés, el primero en describir muchas de las serpientes de la India; su nombre genérico, daboia, viene del hindi y significa "esa cosa oculta" o "la que acecha."
Russel sugegorria (Daboia russelii) Daboia generoko animalia da. Narrastien barruko Viperidae familian sailkatuta dago.
Russel sugegorria (Daboia russelii) Daboia generoko animalia da. Narrastien barruko Viperidae familian sailkatuta dago.
Ketjukyy eli russellinkyy (Daboia russelii, aik. Vipera russellii) on kyykäärmeiden heimoon kuuluva myrkkykäärme. Se aiheuttaa Aasiassa runsaasti kuolemantapauksia varsinkin alueilla, joilla lääkintäpalvelut ovat kaukana ja olot muutenkin alkeelliset. Sitä tavataan Intian, Sri Lankan, Burman ja Thaimaan alueella. Ketjukyy on pohjaväriltään puna- tai kastanjanruskea ja sen selkäpuolta koristavat mustat, vaaleareunaiset läiskät. Pituudeltaan ketjukyy voi olla enimmillään 175 cm pitkä. Se on yöaktiivinen ja syö pikkulintuja, sammakkoeläimiä ja liskoja. Huolimatta saaliseläinten pienestä koosta, sen myrkky on erittäin voimakasta ja yksi purema riittää tappamaan aikuisen ihmisen. Myrkky hyydyttää veren todella nopeasti.[1] Uhri tarvitsee nopeasti vasta-aineruiskeen pureman jälkeen.
Ketjukyy eli russellinkyy (Daboia russelii, aik. Vipera russellii) on kyykäärmeiden heimoon kuuluva myrkkykäärme. Se aiheuttaa Aasiassa runsaasti kuolemantapauksia varsinkin alueilla, joilla lääkintäpalvelut ovat kaukana ja olot muutenkin alkeelliset. Sitä tavataan Intian, Sri Lankan, Burman ja Thaimaan alueella. Ketjukyy on pohjaväriltään puna- tai kastanjanruskea ja sen selkäpuolta koristavat mustat, vaaleareunaiset läiskät. Pituudeltaan ketjukyy voi olla enimmillään 175 cm pitkä. Se on yöaktiivinen ja syö pikkulintuja, sammakkoeläimiä ja liskoja. Huolimatta saaliseläinten pienestä koosta, sen myrkky on erittäin voimakasta ja yksi purema riittää tappamaan aikuisen ihmisen. Myrkky hyydyttää veren todella nopeasti. Uhri tarvitsee nopeasti vasta-aineruiskeen pureman jälkeen.
Daboia russelii est une espèce de serpents de la famille des Viperidae[1] qui se rencontre en Asie du Sud.
En français, elle est nommée Vipère de Russell[2],[1],[3],[4] ou Vipère de Russell des Indes[5],[6].
Principalement à cause de son caractère irritable, elle est responsable de plus d’envenimations mortelles que n’importe quel autre serpent. Sur la plus grande partie de son aire de répartition, cette espèce est considérée comme le vipéridé le plus dangereux et la plus grande cause d’envenimations et de décès : la vipère de Russell est responsable de plus de la moitié des envenimations sérieuses[7] ; et elle fait partie du « big four » soit les quatre espèces de serpents indiens responsables du plus grand nombre de décès avec le cobra à lunettes, le bongare indien et l'échide carénée[8].
Dans la nouvelle policière La bande mouchetée, mettant en scène Sherlock Holmes, un serpent de cette espèce est utilisé comme arme d'un crime.
Ce serpent atteint au maximum 166 cm. La longueur moyenne est de 120 cm sur le continent et les populations insulaires restent plus petites. Il est plus fin que les autres vipères[9]. Ditmars en 1937 rapporte les mensurations suivantes pour un “spécimen de taille moyenne”[10].
Le sommet de la tête est couvert de petites écailles carénées et irrégulières. Les écailles supraoculaires sont étroites, simples, et séparées par 6-9 écailles sur la tête. Les yeux sont grands, tacheté de jaune ou d’or, et chacun est entouré de 10-15 écailles circumorbitaires. Il y a 10-12 supralabiales, les 4e et 5e sont nettement plus larges. L’œil est séparé de la lèvre supérieure par 3-4 rangées de suboculaires. Les deux maxillaires supérieurs portent au moins deux et au plus cinq ou six paires de crochets à la fois : la première est active et ceux de remplacements sont au repos. Les crochets atteignent une longueur de 16 mm en moyenne[2],[11].
Le corps est gros, quasi-cylindrique. Les écailles dorsales sont fortement carénées et seule la rangée inférieure est lisse. À mi-corps, les écailles dorsales sont au nombre de 27-33. On compte 153-180 écailles ventrales. La plaque anale n’est pas divisée. La queue est courte - environ 14 % de la longueur totale du corps et compte 41-68 sous-caudales disposées par paires[2].
La coloration va d’un jaune foncé, brun clair au brun, avec trois séries de taches brun foncé qui courent tout le long du corps. Chacun de ces points est entouré d’un anneau noir, lui-même entouré d’une ligne de couleur blanche ou jaune. Les taches dorsales, habituellement au nombre de 23 à 30, peuvent se développer ensemble, tandis que les taches des flancs peuvent apparaître séparément. La tête a une paire de taches sombres distinctes, l’une sur chaque tempe, avec une marque en V ou en X de couleur rose, saumon ou brun. Derrière l’œil, se trouve une rayure noire, bordée de blanc, rose ou jaune. Le ventre est blanc, blanchâtre, jaunâtre ou rosâtre, souvent avec une dispersion irrégulière de taches sombres[2].
Cette espèce se rencontre au Pakistan, en Inde dans les États du Penjab, d’Himachal Pradesh, du Maharashtra, d’Uttar Pradesh, du Bihar et du Bengale-Occidental, au Sri Lanka, au Bangladesh[1]. La localité type est répertoriée comme « l’Inde ». Plus spécifiquement, ce serait la côte de Coromandel par inférence à Russel (1796)[12].
Sur son aire de répartition elle peut être très commune dans certaines zones et rare dans d’autres[9]. En Inde, elle est abondante au Penjab, très courante le long de la côte de Malabar et ses collines, en Inde du Sud et jusqu’au Bengale-Occidental. Elle est peu courante voire rare dans la vallée du Gange et le nord du Bengale.
Cette espèce ne se limite pas à un habitat particulier, mais tend à éviter les forêts denses. Ce serpent se trouve principalement les prairies ouvertes, herbeuses ou broussailleuses, mais peut également se rencontrer dans les forêts secondaires (jungles broussailleuses), sur les plantations forestières et les terres agricoles. Il est plus fréquent dans les plaines, les basses terres côtières et les collines présentant son habitat habituel. En général, il ne se rencontre pas en altitude, mais a été signalé jusqu’à une hauteur de 2 300 m à 3 000 m. Les milieux humides, comme les marais, les marécages et les forêts tropicales, sont évités[2].
Cette espèce se rencontre souvent dans les zones fortement urbanisées et les habitations à la campagne, attirée par les rongeurs liés à l’activité humaine[11]. En conséquence, les personnes travaillant à l’extérieur dans ces zones sont les plus susceptibles d’être mordus. Il convient de noter, toutefois, que Daboia russelii ne fréquente pas autant les habitations humaines que les espèces des genres Naja et Bungarus (cobras et kraits)[2].
C'est un serpent terrestre et principalement nocturne. Toutefois, pendant la saison fraîche il va modifier son comportement et devenir plus actif pendant la journée[2]. Les adultes Daboia russelii sont constamment lents et paresseux à moins d’être poussés au-delà d'une certaine limite, après quoi ils deviennent violents et agressifs. Les juvéniles, par contre, sont généralement plus irritables et susceptibles de mordre sans provocation[2].
Lorsque ce serpent se sent menacé, il forme une série de boucles en S, soulève le premier tiers du corps et produit un sifflement qui est censé être plus fort que celui de tout autre serpent. Lorsqu’ils frappent depuis cette position, ils peuvent exercer une telle force que même un grand spécimen peut faire décoller la plus grande partie de son corps au-dessus du sol[2]. Il s'agit de serpents difficiles à manipuler : ils sont forts et agiles et peuvent réagir violemment à la capture[8]. La morsure peut être immédiatement relâchée, ou bien ils peuvent s'accrocher pendant plusieurs secondes[11].
Bien que ce genre n'a pas les fosses sensitives de chaleur des Crotalinae, c'est l'un des nombreux viperinés apparemment en mesure de réagir à des stimuli thermiques, renforçant l'idée qu'eux aussi possèdent un organe sensible à la chaleur[13],[14]. L'identité de ce capteur n'est pas certain, mais les terminaisons nerveuses dans le sac supranasal de ces serpents ressemblent à ceux trouvés dans d'autres organes sensibles à la chaleur[15].
Elle se nourrit de rats, de crabes terrestres, de scorpions et d'insectes. Les juvéniles sont crépusculaires et chassant activement. La présence de rongeurs est la principale raison qui fait qu'ils sont attirés par les habitations humaines[2].
On a rapporté de nombreux cas de cannibalisme chez les juvéniles[11].
Cette espèce est ovovivipare[9]. L'accouplement a lieu généralement au début de l'année, bien que des femelles gravides puissent être rencontrées à toute période de l’année. La période de gestation est de plus de six mois. Les jeunes naissent entre mai et novembre, mais surtout en juin et juillet. Des portées de 20 à 40 jeunes sont communes[2], même s'il peut n’y avoir qu’un seul juvénile[11]. Le maximum observé est de 65 dans une même portée. À la naissance, les juvéniles mesurent 215 mm à 260 mm de longueur. La longueur minimale pour une femelle gravide est d'environ 100 cm. Il semble que la maturité sexuelle soit atteinte à 2 ou 3 ans. Il a été observé un cas où il a fallu près de 4,5 heures à un spécimen pour produire 11 jeunes[2].
La quantité de venin produite est considérable. On a signalé pour des spécimens adultes des productions de 130 à 250 mg voire 150-250 mg. Chez les juvéniles, dans un échantillon de treize individus avec une longueur moyenne de 79 cm, les glandes produisaient de 8 à 79 mg avec une moyenne de 45 mg[2].
La DL50 chez la souris, qui est généralement utilisé comme indicateur de la toxicité du venin de serpent, est de 0,08 à 0,31 mg/kg par voie intraveineuse, de 0,40 mg/kg par voie intramusculaire, de 0,75 mg/kg sous-cutanée[16]. La dose létale pour l'Homme est de 40 à 70 mg. En général, la toxicité dépend d'une combinaison de cinq composantes du venin différentes, dont chacune est moins toxique lorsqu'elle est testée séparément. La toxicité du venin varie également au sein des populations et au fil du temps[2].
Les symptômes d'une envenimation commencent par une douleur à l'endroit de la morsure, immédiatement suivie par un gonflement du membre affecté. Le saignement est un symptôme fréquent, en particulier de la gencive, et les crachats peuvent montrer une présence de sang dans les vingt minutes après la morsure. Il y a une baisse de la pression artérielle et la fréquence cardiaque diminue. Des boursouflures apparaissent sur le site de la morsure, et le long du membre atteint dans les cas graves. La nécrose est généralement superficielle et limitée aux muscles près de la morsure, mais peut être sévère dans les cas extrêmes. Vomissements et gonflement du visage se produisent dans environ un tiers des cas[2].
La douleur intense peut durer deux à quatre semaines. Localement, il peut persister en fonction du niveau des lésions tissulaires. Souvent, les pics locaux de gonflement interviennent dans les 48 à 72 heures suivants la morsure, impliquant à la fois le membre affecté et le tronc. Si la personne transpire abondamment dans les deux heures, une envenimation massive est probable. Une décoloration peut se produire dans toute la zone gonflée due au fait que les globules rouges et plasma suintent au travers du tissu musculaire[17]. La mort par septicémie, défaillance respiratoire ou insuffisance cardiaque peut survenir entre un et quatorze jours après la morsure, rarement plus tard[11].
Parce que ce venin est si efficace pour induire une thrombose, il est dans un test diagnostique in vitro de la coagulation sanguine qui est largement utilisé dans les laboratoires hospitaliers. Le coagulant dans le venin active directement le facteur X, qui transforme la prothrombine en thrombine en présence du facteur V et les phospholipides. Le venin est dilué pour donner un temps de coagulation de 23 à 27 s et le phospholipide est réduit pour rendre le test extrêmement sensible aux phospholipides. Le test dVVR est plus sensible que le test TCA pour la détection de l'anticoagulant lupus (une maladie auto-immune), parce qu'elle n'est pas influencée par des carences en facteurs de coagulation VIII, IX ou XI[18].
En Inde, l'Institut Haffkine prépare un sérum antivenimeux polyvalent qui est utilisé pour traiter les morsures de cette espèce[11].
Certains herpétologistes croient que, étant donné le succès de D. russelii en tant qu'espèce et sa réputation terrible dans son environnement naturel, un autre serpent est venu à imiter son apparence. À première vue, le boa des sables, Eryx conicus, possède le même motif de couleurs et ressemble beaucoup à Daboia russelii, même si lui est totalement inoffensif[10],[2].
Cette espèce a été nommée en l’honneur du Dr Patrick Russell (1726-1805) qui fut le premier à décrire l’animal tandis que le genre daboia reprend le nom hindi de ce serpent qui signifie « celui qui épie ».
L'orthographe correcte du nom de l'espèce, Daboia russelii, a été et est encore, un sujet de débat. Shaw et Nodder en 1797, dans leur description de l'espèce Coluber russelii, lui donnèrent le nom du Dr Patrick Russell, mais ont apparemment mal orthographié son nom, avec un seul "L" au lieu de deux. Russell (1727-1805) fut l'auteur de Une énumération des serpents indiens en 1796 et de La suite d'une énumération des serpents indiens en 1801. McDiarmid et al. en 1999 sont parmi ceux qui favorisent l'orthographe d'origine mal orthographiée, invoquant l'article 32C (ii) du Code international de nomenclature zoologique. D'autres, comme Zhao et Adler en 1993 favorisent russellii[12].
Grâce à des études morphologiques et à des analyses de l’ADN mitochondrial, Thorpe et al. en 2007[19] fournit la preuve que l'ancienne sous-espèce de l'Est devrait être considérée comme une espèce distincte, Daboia siamensis.
Les anciennes sous-espèces ont été soit élevée au rang d'espèce soit placées en synonymie avec celle-ci.
Groombridge (1980, 1986) regroupe Vipera palaestinae et Daboia comme un clade fondé sur un certain nombre d’apomorphes partagés, en particulier la forme du museau et la coloration de la tête.
À l'avenir, plusieurs espèces pourraient être ajoutées au genre Daboia. Obst en 1983 a étudié le genre et a suggéré qu'il soit étendu pour inclure Macrovipera lebetina et Vipera xanthina. Lenk et al. en 2001 ont trouvé un appui pour cette idée fondée sur la preuve moléculaire, ce qui suggère que le genre Daboia inclut non seulement Vipera palaestinae, mais aussi Macrovipera mauritanica et Macrovipera deserti[2].
Ces serpents supportent extrêmement bien la captivité, ne nécessitant qu'un plat d'eau et un abri pour se cacher. Les jeunes se nourrissent volontiers de souriceaux, tandis que les adultes mangent des rats, des souris et des oiseaux[2]. Toutefois, de nombreux adultes ne se nourrissent pratiquement pas, avec l’exemple d’un spécimen qui a refusé toute nourriture pendant cinq mois[11]. L'élevage est également assez aisé. Néanmoins, ce sont de très dangereux captifs[2]. Il est arrivé que des spécimens utilisent leurs longs crochets recourbés pour mordre à travers leur mâchoire inférieure dans le pouce de la personne qui les manipulait[8].
Il ne faut pas confondre la vipère de Russell, dont la morsure peut être létale, avec la couleuvre oligodon fasciolatus qui lui ressemble en coloration et en taille mais dont les taches sont nettement différentes et dont la morsure, quoique pouvant être profonde, ne présente aucun danger.
Daboia russelii est une espèce de serpents de la famille des Viperidae qui se rencontre en Asie du Sud.
En français, elle est nommée Vipère de Russell,,, ou Vipère de Russell des Indes,.
Principalement à cause de son caractère irritable, elle est responsable de plus d’envenimations mortelles que n’importe quel autre serpent. Sur la plus grande partie de son aire de répartition, cette espèce est considérée comme le vipéridé le plus dangereux et la plus grande cause d’envenimations et de décès : la vipère de Russell est responsable de plus de la moitié des envenimations sérieuses ; et elle fait partie du « big four » soit les quatre espèces de serpents indiens responsables du plus grand nombre de décès avec le cobra à lunettes, le bongare indien et l'échide carénée.
Dans la nouvelle policière La bande mouchetée, mettant en scène Sherlock Holmes, un serpent de cette espèce est utilisé comme arme d'un crime.
La vipera di Russell (Daboia russelii Shaw e Nodder, 1797) è un serpente della famiglia Viperidae.
Si tratta di un grosso viperide che può sfiorare i 170 cm di lunghezza. Solitamente la sua lunghezza è intorno ai 120 cm. La testa, distinta dal collo, è di forma triangolare. Ha una colorazione di fondo della livrea solitamente brunastra o tendente ad un colore aranciastro con tre serie di macchie circolari di colore marrone scuro bordate di nero per la lunghezza del suo corpo.
La vipera di Russell è diffusa in gran parte del sud-est asiatico. È stata trovata in Pakistan, India, Sri Lanka, Bangladesh, Nepal, Myanmar, Thailandia, Cambogia, Cina (Guangxi, Guangdong), Taiwan e Indonesia (Endeh, Flores, est Giava, Komodo, isole Lomblen). Non è limitata a un particolare habitat, ma evita folti boschi, perciò viene scovata maggiormente in zone aperte. È possibile però trovarla anche presso piccoli boschi e piantagioni. Essa è più comune nelle pianure costiere e in collina. In genere non vive ad alta quota, ma è stata segnalata anche a 2300–3000 m. Evita ambienti umidi, come paludi e foreste pluviali.
Di indole mite, è un animale terrestre, attivo soprattutto di notte. Durante le giornate più fredde può però modificare le sue abitudini, diventando più attivo di giorno[1]. La sua dieta è essenzialmente costituita da insetti, piccoli rettili come le lucertole e topi negli esemplari giovani e da mammiferi, topi ed altri piccoli serpenti negli esemplari adulti. I giovani possono essere cannibali[2].
È una specie ovovivipara. Gli accoppiamenti avvengono solitamente nei primi mesi dell'anno. Il periodo di gestazione è superiore a sei mesi. I piccoli nascono da maggio, con maggiore frequenza nei mesi di luglio e agosto. Le nidiate di 20-40 piccoli sono comuni, il massimo registrato è di 65 in un'unica nidiata. La lunghezza per un esemplare femmina gravida è di circa 100 cm. Pare che la maturità sessuale sia raggiunta nel giro di 2-3 anni.
Questa specie è molto pericolosa per l'uomo, detiene infatti il triste record di massimo avvelenatore in India, dove ogni anno circa 10.000 persone muoiono in seguito al suo morso. Questa specie non è particolarmente aggressiva; tuttavia, a causa della sua pigrizia, in genere non avverte il malcapitato della sua presenza (al contrario di serpenti più aggressivi e velenosi come cobra o mamba), mordendolo solo quando questo è inconsapevolmente molto vicino al serpente.
L'elevata mortalità è da attribuirsi, oltre alla già citata pigrizia e scarsa tendenza all'allontanamento, alla convivenza dell'uomo e dell'animale negli stessi territori e, soprattutto, al fatto che non vengono osservate le più comuni precauzioni; ad esempio, la maggior parte dei contadini, per via della povertà, non indossa calzature e ciò accresce la vulnerabilità dell'uomo e, di conseguenza, la mortalità.
Il veleno contiene tossine ad azione emotossica e citotossica. Il veleno produce immediatamente un forte dolore nella zona del morso, dopo circa 20 minuti si possono avere emorragie alla bocca, alle gengive, oltre a una riduzione improvvisa della frequenza cardiaca e crollo della pressione sanguigna. Nei casi più gravi si possono in seguito avere emorragie sistemiche, trombosi, blocco renale (che si verifica in circa il 30% dei morsi non trattati) cardiaco o respiratorio. La morte può avvenire dopo 1-14 giorni e anche oltre.
In caso di sopravvivenza al morso, il veleno può avere gravi conseguenze permanenti come ipopituitarismo (che a sua volta può indurre altre endocrinopatie come ipogonadismo, ipotiroidismo, malattia di Addison etc.) e conseguente sterilità. L'ipopituitarismo si verifica nel 29% delle persone morse.[3]
La dose iniettata è di circa 21–268 mg a morso. In generale 40–70 mg di veleno sono sufficienti ad uccidere un uomo adulto di sana costituzione.
Raselo angis (lot. Daboia russelii) – angių (Viperidae) šeimos gyvatė.
Ši gyvatė yra viena iš pavojingiausių ir nuodingiausių pasaulyje, priklauso „Didžiajam ketvertui“, gyvatės kurios nužudo daugiausiai žmonių. Raselo angies nuodai naikina arterijos sieneles ir sukelia didelį kraujavimą.
Raselo angis užauga nuo 125 cm iki 160 cm. Gyvena pietų Azijoje, Indonezijoje ir pietryčių Azijoje.
Raselo angis (lot. Daboia russelii) – angių (Viperidae) šeimos gyvatė.
Ši gyvatė yra viena iš pavojingiausių ir nuodingiausių pasaulyje, priklauso „Didžiajam ketvertui“, gyvatės kurios nužudo daugiausiai žmonių. Raselo angies nuodai naikina arterijos sieneles ir sukelia didelį kraujavimą.
Raselo angis užauga nuo 125 cm iki 160 cm. Gyvena pietų Azijoje, Indonezijoje ir pietryčių Azijoje.
Russells hoggorm (vitenskapelig navn Daboia russelii) er en giftig slange av hoggormfamilien (viperidae). Den er eneste art i slekten Daboia. Slangen har navn etter herpetologen Patrick Russell, som først beskrev den.
Russells hoggorm lever over store deler av Asia; på det indiske subkontinentet, i mesteparten av Sørøst-Asia, det sørlige Kina og Taiwan. Den har en sterk gift, og regnes som en av verdens farligste slanger.
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Denne zoologirelaterte artikkelen er foreløpig kort eller mangelfull, og du kan hjelpe Wikipedia ved å utvide den. Russells hoggorm (vitenskapelig navn Daboia russelii) er en giftig slange av hoggormfamilien (viperidae). Den er eneste art i slekten Daboia. Slangen har navn etter herpetologen Patrick Russell, som først beskrev den.
Russells hoggorm lever over store deler av Asia; på det indiske subkontinentet, i mesteparten av Sørøst-Asia, det sørlige Kina og Taiwan. Den har en sterk gift, og regnes som en av verdens farligste slanger.
Daboja łańcuszkowa, żmija łańcuszkowa (Daboia russelii) – wąż z rodziny żmijowatych.
Wąż ten żyje w południowo-wschodniej Azji: na subkontynencie indyjskim, na półwyspie indochińskim, w południowych Chinach i na Tajwanie. Z powodu ich bardzo efektywnego jadu i częstego pojawiania się w miejscach zamieszkanych przez ludzi, żmija ta jest uważana za najniebezpieczniejszego węża Azji Południowej, przypisywanych jej jest około 900 przypadków śmiertelnych rocznie.
Wielkość węża jest zróżnicowana regionalnie. Populacje na Sri Lance są relatywnie małe, o przeciętnej długości ok. 0,90 m do maksymalnie 1,5 m. W Chinach węże te osiągają rozmiary od 1,0 do 1,2 m, niektóre mają nawet 1,67 m, natomiast w Indiach przeciętna długość wynosi 1,20 m, największe osobniki mają tam ok. 1,85 m. Głowa węża o długości 1,20 m ma około 5 cm. Daboja łańcuszkowa w porównaniu do innych żmij nie cechuje się okazałą budową ciała. Głowa jest spłaszczona i ma kształt trójkątny, wyraźnie odstaje od reszty korpusu.
Daboja łańcuszkowa jest aktywna głównie nocą, szczególnie zaraz po zachodzie słońca. Jednakże przy szczególnie zimnej pogodzie ich aktywność przypada także za dnia. Żyje przeważnie na ziemi, chowa się z zaroślach i wysokiej trawie, dobrze się kamuflując. Porusza się dosyć ospale, jednak młodsze osobniki są bardziej aktywne. W razie zagrożenia wąż zwija się i unosi przednią część ciała, sycząc przy tym wyraźnie i głośno. Z tej pozycji, przy ataku porusza swoje ciało z wielką siłą naprzód, tak że niekiedy traci ono chwilowo kontakt z podłożem. Generalnie dorosłe osobniki są spokojniejsze i mniej drażliwe niż młodsze.
Ich jad jest śmiertelnie niebezpieczny dla człowieka. U większości ludzi dawka od 40 do 70 mg jest śmiertelna, co czyni ich jad o wiele bardziej efektywnym w porównaniu do innych rodzajów węży, takich jak kobry, grzechotniki czy mamby. Przeciętnie żmija przy ugryzieniu wstrzykuje około 72 mg jadu, przy niektórych egzemplarzach stwierdzono nawet ilości od 150 do 250 mg na jedno ukąszenie, co odpowiada całej zawartości ich gruczołów jadowych.
Węże (Serpentes)
Alethinophidia Daboja łańcuszkowa, żmija łańcuszkowa (Daboia russelii) – wąż z rodziny żmijowatych.
A víbora-de-russell (Daboia russelii) é uma espécie de serpente venenosa da família Viperidae. Daboia é um género monotípico[2] de víboras venenosas do Velho Mundo. A única espécie deste género, D. russelii, é encontrada na Ásia em todo o subcontinente indiano, grande parte do sudeste asiático, sul da China e Taiwan.[1] O epíteto específico desta espécie foi escolhido como homenagem a Patrick Russell (1726–1805),[3] um herpetólogo escocês que foi o primeiro a descrever muitas das serpentes indianas, e o nome do género é uma palavra hindi que significa "que permanece escondido", ou "espreitador".[4] Além de ser uma das quatro grandes serpentes da Índia, Daboia é também um dos géneros responsável pelo maior número de incidentes e mortes por mordeduras de serpentes dentre todas as serpentes venenosas devido a vários factores, como a sua ampla distribuição geográfica, temperamento geralmente agressivo, e a sua presença frequente em zonas populosas.[5]
Daboia russelli é vulgarmente conhecida como víbora-de-russell, entre outros nomes.[6][7]
D. russelii pode atingir um comprimento total máximo (corpo + cauda) de 166 cm e 120 cm em média entre as populações asiáticas continentais, embora as populações insulares possam ser ligeriamente menores, em média.[6] Tem constituição mais esbelta do que a maioria das víboras.[8] Ditmars (1937) reportou as seguintes dimensões para um "espécime adulto de bom tamanho":[9]
A cabeça é achatada, triangular, e distinta do pescoço. O focinho é rombo, arredondado, e levantado. As narinas são grandes, cada uma situada no meio de uma única grande escama nasal. A orla inferior da escama nasal toca a escama nasorostral. A escama supranasal tem forma de crescente, e separa anteriormente a escama nasal da escama nasorostral. A escama rostral é larga e alta.[6]
A coroa da cabeça está coberta por escamas irregulares muito fragmentadas. As escamas supra-oculares são estreitas, singulares e separadas por seis a nove escamas transversais à cabeça. Os olhos são grandes, com manchas amarelas ou douradas, e rodeados por 10 a 15 escamas circum-orbitais. Esta serpente tem 10 a 12 escamas supralabiais, a quarta e quinta das quais são significativamente maiores. Os olhos são separados das escamas supralabiais por três ou quatro filas de escamas suboculares. Apresenta dois pares de escamas geniais, a quarta e quinta das quais são significativamente maiores que as demais. Os dois ossos maxilares suportam pelo menos dois e até cinco ou seis pares de presas simultâneamente: os primeiros estão activos e os demais são de substituição.[6] As presas atingem um comprimento de 16,5 mm num espécime médio.[10]
O corpo é grosso, e em corte transversal tem forma arredondada a circular. As escamas dorsais são fortemente enquilhadas; apenas a fila mais baixa é suave. A meio-corpo, contam-se 27 a 33 escamas dorsais. As escamas ventrais são de 153 a 180. A placa anal é indivisa. A cauda é curta, cerca de 14% do comprimento total, com escamas subcaudais emparelhadas que são de 41 a 68.[6]
O dorso apresenta uma padrão de cores consistindo de um amarelo profundo, bronze ou castanho terroso, com três séries de manchas castanho-escuro dispostas longitudinalmente ao corpo. Cada uma destas manchas tem um anel negro em seu redor, cujo limite exterior é sublinhado com uma orla de branco ou amarelo. As manchas dorsais, que normalmente são de 23 a 30, podem crescer juntas, enquanto as manchas lateriais podem separar-se. A cabeça tem um par de manchas escuras distintivas, uma em cada têmpora, junto com uma marca em forma de X ou V de cor rosada ou acastanhada que forma um ápice na direcção do focinho. Atrás do olho tem um uma risca negra, com contorno branco ou rosado. O ventre é branco, amarelado ou rosado, frequentemente com manchas escuras dispersas de forma irregular.[6]
D. russelii pode ser encontrada na Índia, Sri Lanka, Bangladesh, Nepal, Mianmar, Tailândia, Paquistão, Camboja, Tibete, China (Guangxi, Guangdong), Taiwan e Indonésia (Endeh, Flores, Java oriental, ilhas de Komodo e Lomblen). A localidade-tipo indicada é "Índia". Mais especificamente, tratar-se-ia da Costa de Coromandel, por inferência de Russell (1796).[1]
Brown (1973) menciona que também pode ser encontrada no Vietname, Laos, e na ilha indonésia de Sumatra.[11] Ditmars (1937) supostamente recebeu igualmente um espécime de Sumatra.[9] Porém, a distribuição desta espécie no arquipélago indonésio, não é ainda conhecida de forma clara.[12]
Dentro da sua zona de distribuição, pode ser muito comum em algumas áreas e escassa noutras.[8] Na Índia, é abundante no Punjab, muito comum ao longo da costa ocidental e suas montanhas, no sul da Índia e para norte até Bengala, e Assam. É prevalente em Mianmar.[10] É ainda comum na Tailândia na região de Pattaya e outras localidades turísticas onde as suas principais presas, os ratos, dispõem de alimento abundante.
A D. russelii não se restringe a um habitat particular, mas tende a evitar florestas densas. Esta serpente é encontrada sobretudo em áreas abertas com vegetação herbácea ou arbustiva, mas pode também ser encontrada em zonas de floresta secundária, em plantações florestadas e terrenos de cultivo.É comum em planícies, terras baixas costeiras, e elevações com habitat adequado. Geralmente, não é encontrada a altitudes elevadas, mas existem relatos de observações a altitudes entre os 2 300 e os 3 000 metros. Evita os ambientes húmidos, como marismas, pântanos e bosques tropicais.[6]
Esta espécie é frequentemente encontrada em áreas urbanizadas e assentamentos rurais, sendo atraída pelos roedores comensais das populações humanas.[10] Por esta razão, aquelas pessoas que trabalham no exterior nestas zonas correm um maior risco de ser mordidas. D. russelii não está tão associada às habitações humanas como as espécies do géneros Naja e Bungarus.[6]
D. russelii é terrestre e caça sobretudo durante a noite. Contudo, durante épocas de clima mais fresco, modifica o seu comportamento, tornando-se mais activa durante o dia.[6]
Os indivíduos adultos são geralmente lentos excepto se forem incomodados para lá de um certo limite, a partir do qual podem tornar-se muito agressivos. Por outro lado, os juvenis são geralmente mais nervosos.[6]
Quando ameaçadas, formam com o corpo uma série de voltas em S, erguem o primeiro terço do corpo, e produzem um silvo que é supostamente o mais forte dentre todas as serpentes. Quando atacam desde esta posição, podem gerar uma força tal que até um indivíduo de grande tamanho pode levantar a maior parte do corpo do solo.[6] Estas serpentes são fortes e podem reagir de forma violenta quando agarradas.[5] A mordedura pode ser de duração muito curta ou durar muitos segundos.[10]
Embora este género não esteja provido dos órgãos sensíveis ao calor comuns entre os Crotalinae, é um dentre vários viperinos que podem aparentemente reagir a estímulos térmicos, o que parece apoiar a ideia de também eles possuírem um órgão sensorial sensível ao calor.[13][14] A identidade deste sensor não é conhecida com certeza, mas as terminações nervosas no saco supranasal destas serpentes assemelham-se às encontradas em outros órgãos sensíveis ao calor.[15]
D. russelii é uma espécie ovovivípara.[8] O acasalamento ocorre geralmente no início do ano, embora as fêmeas prenhes possam ser encontradas ao longo de todo o ano. O período de gestação é maior que seis meses. Os juvenis nascem de maio a novembro, mas sobretudo entre junho e julho. São procriadores prolíficos. As ninhadas com 20 a 40 juvenis são comuns,[6] embora o número de crias possa ser menor, inclusivamente até apenas uma.[10] O máximo relatado é 75[16] crias de uma mesma ninhada. À nascença os juvenis têm comprimento total entre 215 e 260 mm. O comprimento total mínimo para uma fêma prenhe é aproximadamente 1 m. Aparentemente a maturidade sexual é atingida por volta dos 2-3 anos de idade. É conhecido um caso em que um espécime demorou quase 4,5 horas para dar à luz 11 crias.[6]
D. russelii alimenta-se sobretudo de roedores, especialmente de espécies de murídeos. Porém, pode comer de quase tudo, incluindo ratazanas, ratos, toupeiras, esquilos, lagartos,caranguejos terrestres, escorpiões e outros artrópodes. Os juvenis têm hábitos crepusculares, alimentando-se de lagartos e buscando activamente alimento. À medida que crescem e se tornam adultos, começam a especializar-se em roedores. De facto, a presença de roedores e lagartos é a principal razão pela qual estas serpentes são atraídas a habitações humanas.[6]
Sabe-se que os juvenis podem ser canibais.[10]
Alguns herpetólogos crêem que como D. russelii é uma espécie bem-sucedida, e com uma reputação temível no seu ambiente natural, outra serpente mimetiza a sua aparência. Superficialmente, a boa-da-areia, Gongylophis conicus, possui um padrão de cores que frequentemente se assemelha ao de D. russelii, embora seja completamente inofensiva.[6][9]
A quantidade de veneno produzida por espécimes individuais de D. russelii é considerável. Os volumes de veneno reportados para espécimes adultos variam de 130-250 mg até 21-268 mg. Para 13 juvenis com um comprimento total médio de 79 cm, o volume médio de veneno medido foi 8-79 mg (média 45 mg).[6]
O valor de LD50 para ratos, que é usado como possível indicador da toxicidade do veneno da serpente, é 0.133 mg/kg intravenoso,[17] 0.40 mg/kg intraperitoneal,[18] cerca de 0.75 mg/kg subcutâneo.[19] Para a maioria dos humanos, uma dose letal é aproximadamente 40–70 mg. Em geral, a toxicidade depende de uma combinação de cinco fracções de veneno diferentes, sendo cada uma delas menos tóxica quando testada separadamente. A toxicidade do veneno e os sintomas produzidos pela mordedura em humanos varia dentro de uma mesma população e ao longo do tempo.[6]
Os sintomas de envenenamento começam com dor no local da mordedura, imediatamente seguido por inchaço da extremidade afectada. Hemorragias são um sintoma comum, especialmente nas gengivas e urina, e as secreções respiratórias podem apresentar sinais de sangue vinte minutos depois da mordedura. A pressão arterial desce e o ritmo cardíaco diminui. Formam-se bolhas no local da mordedura, as quais se podem estender pelo membro afectado em casos severos. A necrose é normalmente superficial e limitada aos músculos próximos do local da mordedura, mas pode ser severa em casos extremos. Num terço de todos os casos ocorre vómito e edema facial.[6] Em 25 a 30% dos casos não tratados ocorre também falha renal. Em casos de envenenamentos severo pode ocorrer também coagulação intravascular disseminada severa. O tratamento médico imediato e o acesso a antiveneno podem evitar ou diminuir drasticamente a probabilidade de desenvolver complicações severas potencialmente letais.
A dor severa pode durar de 2 a 4 semanas. Localmente, pode persistir dependendo do grau de danos sofridos pelo tecido. Frequentemente, o inchaço local atinge o seu máximo depois de 48 a 72 horas, afectando tanto o membro afectado como o tronco. Se ocorre inchaço do tronco 1 a 2 horas depois da mordedura, é provável que o envenenamento seja severo. A zona inchada pode apresentar descoloração devida à passagem de eritrócitos e plasma para o tecido muscular.[20] A morte por septicemia ou por falência renal, respiratória ou cardíaca pode ocorrer entre 1 e 14 dias após a mordedura ou até mais tarde.[10]
Um estudo publicado em The Lancet mostrava que dentre uma amostra de pessoas que sobreviveram depois de ser mordidas por D. russelii, 29% delas sofreu danos consideráveis à glândula pituitária, que mais tarde resultaram em hipopituitarismo.[21] Outros estudos científicos apoiam a hipótese de as mordeduras de D. russelii poderem causar hipopituitarismo.[22][23][24]
Como este veneno é tão eficaz na indução da trombose, é usado num teste de diagnóstico in vitro da coagulação sanguínea amplamente usado nos laboratórios hospitalares. Este teste é frequentemente designado ensaio do veneno da víbora-de-russell diluído. O coagulante presente no veneno activa directamente o factor X, que transforma a protrombina em trombina na presença do factor V e fosfolípido. Este teste é mais sensível que o teste TTPA na detecção do anticoagulante lúpico, pois não é influenciado por deficiências dos factores de coagulação VIII, IX ou XI.[25]
Na Índia, o Haffkine Institute prepara um antiveneno polivalente que é usado no tratamento de mordeduras desta espécie.[10]
Utilizando dados morfológicos de ADN mitocondrial, Thorpe et al. (2007)[28] obtiveram evidências de que a subespécie oriental de D. russelii deveria ser considerada como uma espécies separada, Daboia siamensis.
Várias outras subespécies podem ser encontradas na literatura,[6] incluindo:
A ortografia do epíteto específico, russelii, tem sido, e ainda é, objecto de discussão. Shaw & Nodder (1797), na sua descrição da espécie Coluber russelii, nomearam-na em honra de Patrick Russell, mas aparentemente grafaram o nome de forma incorrecta, usando apenas um "L" em vez de dois. Russell (1727–1805) foi o autor de An Account of Indian Serpents (1796) e A Continuation of an Account of Indian Serpents (1801). McDiarmid et al. (1999) encontram-se entre aqueles que favorecem a grafia incorrecta original, citando o Artigo 32c (ii) do Código Internacional de Nomenclatura Zoológica. Outros, como Zhao & Adler (1993) favorecem russellii.[1]
É possível que no futuro, mais espécies sejam adicionadas a Daboia. Obst (1983) fez uma revisão do género e sugeriu que deveria ser ampliado de forma a incluir Macrovipera lebetina, Vipera palaestinae, e V. xanthina. Groombridge (1980, 1986) unificou V. palaestinae e Daboia num clado baseando-se em várias apomorfias partilhadas, incluindo a forma do focinho e o padrão de cores da cabeça. Lenk et al. (2001)[29] encontrou apoio para esta ideia com base em evidências moleculares, sugerindo que Daboia inclua não só V. palaestinae, como também M. mauritanica e M. deserti.[6]
A víbora-de-russell (Daboia russelii) é uma espécie de serpente venenosa da família Viperidae. Daboia é um género monotípico de víboras venenosas do Velho Mundo. A única espécie deste género, D. russelii, é encontrada na Ásia em todo o subcontinente indiano, grande parte do sudeste asiático, sul da China e Taiwan. O epíteto específico desta espécie foi escolhido como homenagem a Patrick Russell (1726–1805), um herpetólogo escocês que foi o primeiro a descrever muitas das serpentes indianas, e o nome do género é uma palavra hindi que significa "que permanece escondido", ou "espreitador". Além de ser uma das quatro grandes serpentes da Índia, Daboia é também um dos géneros responsável pelo maior número de incidentes e mortes por mordeduras de serpentes dentre todas as serpentes venenosas devido a vários factores, como a sua ampla distribuição geográfica, temperamento geralmente agressivo, e a sua presença frequente em zonas populosas.
Daboia russelli é vulgarmente conhecida como víbora-de-russell, entre outros nomes.
* Daboia - Gray, 1840 (nomen nudum)
Daboia zehirli bir engerek türü olan daboia russelii için oluşturulmuş monotipik bir cinstir.[8] Hindistan alt kıtası boyunca Asya'da, Güneybatı Asya, Çin ve Tayvan'ın çoğu bölgesinde bulunur.[1] Yaşam alanının büyük kesiminde yılan ısırıklarının ve bundan kaynaklı ölümlerin en büyük sorumlusu olan engerek türüdür.[2] Tür neredeyse Hindistan'daki tüm yılan ısırığı kaynaklı ölümlere sabep olan dört büyük yılan arasında yer alır. Russell engereği adını bu hayvanı ilk tanımlayan Dr. Patrick Russell'dan (1726 - 1805) almıştır. Biri aday olmak üzere, iki alt türü bulunmaktadır.[9]
Yılan maksimum 166 cm (5.5 ft) uzunluğa erişebilir. Ortalama uzunluk anakarada 120 cm'dir (4 ft) ancak ada populasyonunda bu uzunluğa erişen yoktur.[2] Diğer çoğu engerekten daha inci bir yapıya sahiptir.[10] Ditmars'ın (1937) raporuna göre ortalama boyutta bir yetişkine ait ölçüleri aşağıdaki gibidir:[11]
Basık ve üçgen şeklinde olan baş boyundan belirgin bir şekilde ayrılır. Burun kısmı küt, yuvarlak ve kabarıktır. Burun delikleri (nostril) büyüktür ve büyük, tek parça olan burun pulunun (nasal pul) ortasında bulunur.
Pakistan, Hindistan, Sri Lanka, Bangladeş, Nepal, Myanmar, Tayland, Kamboçya, Çin (Guangxi, Guangdong), Tayvan ve Endonezya'da (Endeh, Flores, Doğu Java, Komodo, Lomblen Adaları) bulunur. Cinsin tip yeri "Hindistan" olarak listelenir. Daha spesifik olarak tip yeri, Russell'ın (1796) çıkarımıyla Koromondel Kıyısı olarak belirtilebilir.[1]
Brown (1973) yılanın Vietnam, Laos ve Sumatra adasında da bulunabileceğinden söz eder.[13] Ditmars da (1937) Sumatra'da bir örnek elde ettiğini rapor etmiştir.[11] Yine de bu türün Endonezya'daki dağılımı konusu henüz tam olarak açıklığa kavuşmuş değildir.[19]
Russell engereği dağılım bölgesindeki bazı yerlerde çok yaygındır bazı yerlerde ise çok nadir görünür.[10] Hindistan'da, Punjab'da oldukça bol bulunur, batı kıyısı boyunca ve güney Hindistan'dan Bengal'e kadar da yaygındır. Ganj vadisinde, Bengal'in kuzeyinde ve Assam'da nadir görülür. Myanmar'da da çok rastlanır.[15]
Thorpe et al. (2007) morfolojik ve mitokondriyal DNA verilerini kullanarak batılı alt türlerin, ayrı bir tür (Daboia siamensis) olarak kbul edilebileceğine dair kanıtlar buldular.[22]
Literatürde bir takım farklı alt türlere de rastlanabilir.[2]
D. russelii'nin yazımı geçmişte olduğu gibi günümüzde de tartışma konusudur. Shaw & Nodder (1797) Coluber russelii türüyle ilgili raporlarında yılanı Dr. Patrick Russell'ın anısına isimlendirmişlerdi. Ancak anlaşıldığı kadarıyla, yanlış yazım sonucunda Dr. Russell'ın ismini çift L yerine tek L ile yazmışlardı. Russell (1727–1805) An Account of Indian Serpents (1796) ve A Continuation of an Account of Indian Serpents (1801) kitaplarının yazarıdır. McDiarmid et al. (1999) Uluslararası Zooloji Adlandırma Kodu'nun 32c (ii) maddesine atıfta bulunarak orijinal yanlış yazımı benimseyenler arasındadır. Zhao ve Adler (1993) gibi bazıları da russellii yazımını benimsemişlerdir.[1]
Gelecekte daha farklı türler de Daboia cinsine dahil edilebilir. Cinsi gözden geçiren Obst (1983) cinsin Macrovipera lebetina, Vipera palaestinae ve V. xanthina türlerini de içine alacak şekilde genişletilebileceğini belirtti.
Bazı herpetologlar, Russell engereğinin doğal çevresinde çok başarılı ve korkunç şöhrete sahip bir tür olduğundan ötürü, başka bir yılanın onun görüntüsüne büründüğüne inanmaktadırlar. Bir kum boası türü olan Gongylophis conicus tamamen zararsız bir yılan olmasına rağmen Russell engereği ile büyük benzerlik gösteren bir renk desenine sahiptir.[2][11]
Daboia zehirli bir engerek türü olan daboia russelii için oluşturulmuş monotipik bir cinstir. Hindistan alt kıtası boyunca Asya'da, Güneybatı Asya, Çin ve Tayvan'ın çoğu bölgesinde bulunur. Yaşam alanının büyük kesiminde yılan ısırıklarının ve bundan kaynaklı ölümlerin en büyük sorumlusu olan engerek türüdür. Tür neredeyse Hindistan'daki tüm yılan ısırığı kaynaklı ölümlere sabep olan dört büyük yılan arasında yer alır. Russell engereği adını bu hayvanı ilk tanımlayan Dr. Patrick Russell'dan (1726 - 1805) almıştır. Biri aday olmak üzere, iki alt türü bulunmaktadır.
Con nưa, rắn hổ bướm (danh pháp hai phần: Daboia russelii) là một loài rắn độc trong chi Daboia[2] rắn độc Cựu Thế giới. D. russelii của chi Daboia phân bố khắp châu Á từ tiểu lục địa Ấn Đố, phần lớn Đông Nam Á, phía nam Trung Quốc và Đài Loan.[1] Nó là một thành viên của rắn độc big four ở Ấn Độ.[3] Nó là loài gây ra phần lớn các vụ rắn cắn và tử vong trên thế giới do nhiều yếu tố như việc nó xuất hiện thường xuyên ở những nơi có con người sinh sống. Tên của nó được đặt theo Patrick Russell (1726–1805), một nhà nghiên cứu bò sát Scotland người đã mô tả nhiều loài rắn Ấn Độ, còn chi này được đặt theo tên Hindi có nghĩa "that lies hid", hay "the lurker."[4] Có hai phụ loài hiện được công nhận.
Con nưa, rắn hổ bướm (danh pháp hai phần: Daboia russelii) là một loài rắn độc trong chi Daboia rắn độc Cựu Thế giới. D. russelii của chi Daboia phân bố khắp châu Á từ tiểu lục địa Ấn Đố, phần lớn Đông Nam Á, phía nam Trung Quốc và Đài Loan. Nó là một thành viên của rắn độc big four ở Ấn Độ. Nó là loài gây ra phần lớn các vụ rắn cắn và tử vong trên thế giới do nhiều yếu tố như việc nó xuất hiện thường xuyên ở những nơi có con người sinh sống. Tên của nó được đặt theo Patrick Russell (1726–1805), một nhà nghiên cứu bò sát Scotland người đã mô tả nhiều loài rắn Ấn Độ, còn chi này được đặt theo tên Hindi có nghĩa "that lies hid", hay "the lurker." Có hai phụ loài hiện được công nhận.
山蝰屬（學名：Daboia，俗稱「七步紅」、「鎖鏈蛇」）是蛇亞目蝰蛇科蝰亞科下的一個單型屬[1]，屬下有4種，而山蝰（D. russelii）為主要的一種有毒蛇類，主要分布於亞洲至印度次大陸地區、東南亞、中國南部及台灣。[2]由於山蝰的分布範圍甚廣，因此被視為南亞區域最危險的蛇類之一，大部份遭蛇咬傷以及導致死亡的事件都與其有關。[3]山蝰是印度著名四大毒蛇的其中一員，亦是引發印度境內幾乎所有人類遭蛇咬斃事故的元兇。[4]山蝰的拉丁學名「D. russelii」來自最早發現山蝰的爬蟲學家柏德烈·羅素（Patrick Russell，1726-1805）博士；而其屬的學名「Daboia」則來自印地語，意指「潛伏者」。[5]目前共已被確認有四個物種，其中圓斑蝰「Daboia siamensis」為台灣六大毒蛇之一。[6]
山蝰最長能達166公分，分布於陸地的山蝰普遍比海島上的山蝰為長。[3]相較其它蝰蛇而言，山蝰的體格比較幼細。[7]學者迪馬斯（Ditmars，1937）曾撰寫一份報告，明確顯示一條「正常成年山蝰」的體型數據：[8]
山蝰頭部形狀扁平，呈三角形，與頸部有明顯分野。鼻端圓鈍，微向上翹，只有單片鼻鱗，鼻孔偏大；鼻鱗下緣碰到鼻尖，其鼻上鱗片呈彎月形，將鼻鱗與鼻尖鱗分開。其吻鱗的寬度則與吻鱗長度相等。[3]
山蝰頭頂滿佈零星細碎的不規則鱗片，眶上鱗為單片大片結構，形狀狹隘，由6至9片小鱗橫截開來。山蝰眼睛碩大，有黃色或金色的斑點，雙眼外眶各有10至15片眶鱗。另外，山蝰共有10至12片上唇鱗，當中第四及第五片明顯較為大片；有兩對頦鱗，前對較為巨大。顎骨上佈有至少兩枚、至多五至六枚的尖牙，最前的一雙尖牙是頻密使用的，其它尖牙則屬於後備性質。山蝰的尖牙長度平均約有1.6公分。[9]
山蝰身型雖然較其它蝰蛇幼身，但體格仍屬於粗壯的，軀體的橫切面大致為圓形或管形。背鱗呈鮮明的龍骨形結構，為數約27至33片；腹鱗為數153至180片，肛鱗只有單片。山蝰尾部較短，大約只佔全身的14%，成對的尾下鱗約有41至68片。[3] 山蝰的顏色以深黃色、棕色為基調，身上有三串縱向連貫的圓點斑紋。這些圓點以白色為主，外圍有黑線圍繞。背部圓斑約有23至30塊，圓斑間大多連貫而生，也有可能會在成長過程中分離。[3]
山蝰主要分布於巴基斯坦、印度、斯里蘭卡、孟加拉國、尼泊爾、孟買、泰國、柬埔寨、中國大陆（廣西、廣東）、台灣地区及印尼。其標準產地為「印度（India）」，根據羅素（1796）研究，更準確的說法應該是印度的烏木海岸。[2]
布朗（Brown，1973）指出山蝰亦分布於越南、寮國及蘇門答臘。[11]迪馬斯（Ditmars，1937）亦指出蘇門答臘曾發現山蝰的蹤影。[8] 然而至今為止，對於山蝰在印尼群島的分布情形，尚未有清晰的結論。[12]山蝰的分布狀態十分極端，在某些地區牠們極為常見（如印度的旁遮普邦西岸及山群、南印度、緬甸，與及孟加拉），同時在一些其它地區則十分罕見（如恆河流域及阿薩姆邦）。[9]
山蝰的出沒並不限制於任何環境，但似乎較傾向遠離密林地帶。山蝰常見於多草、多灌木的開放式地形，也會出沒於矮樹林及農地。山蝰最常棲息的地方是平原、沿岸低地與及山群，其所處海拔至高約限於2300至3000米。牠們會避免於潮濕的環境中出沒。[3] 另外，由於人類聚居的建築物容易滋養鼠類，這一點形成了對山蝰的吸引，令山蝰亦經常出沒於部份城市化地區；[9] 因此，一些在室外工作的人類可能會遭受山蝰的攻擊。不過，相較於眼鏡蛇及環蛇，山蝰並非屬於相當接近人類聚居地的一種蛇類。[3]
山蝰屬於陸行性，多於夜間出沒。然而，當氣候轉寒的時候，山蝰也會於日間活動。[3]
成年的山蝰行動偏向遲緩，在受到威脅及挑釁時會攻擊防衛。相對於成年山蝰，幼體較為緊張，警惕性較高。[3]
山蝰受到外界威脅時，牠們會把身體蜷成「S」狀，並仰起身體三分一的前軀，向敵人示以威嚇。牠們能爆發相當大的體能並會緊咬著對手，甚至可以將一些體型大的對手咬離地面。[3]要徒手拿起山蝰困難，因為牠們體格強壯、身段靈活，而對於被挾持的反應更是猛烈，並會發動攻勢。[4]牠們的咬擊可能是一發即收的，也有可能緊咬對手達數秒之久。[9]
雖然山蝰如其它蝰蛇般並沒有熱能感測頰窩，但牠明顯地仍能對溫感有所反應，因此牠們可能有另一種形式的熱能感測器官。[13][14]研究目前對這種器官的探析仍甚不足，但可發現位於山蝰鼻上氣囊的神經末梢結構，頗像其它蛇類的熱能感測器官。[15]
山蝰主要進食齧齒目動物，尤其是鼠科生物。山蝰幼蛇多於黃昏時份活動，主要捕食蜥蜴。也有報告指它們甚至會同類相食。[9]當山蝰成長後，鼠類便會成為其主要食物，這也解釋了為何山蝰經常出現於人類居住地，因為那裡的老鼠數量很多。[3]
山蝰是卵胎生動物。[7]雖然無論在甚麼時候都有機會發現懷孕的雌性山蝰，但山蝰多於每年的首數個月份內進行交配。妊娠期約為六個月，每年的五月至十一月（尤於六月及七月）時就會誕下幼蛇。山蝰屬於多產蛇類，每胎約能產下20至40條幼蛇。[3]紀錄中最長的幼蛇為65公分，初生時平均約長21至26公分。懷孕雌性山蝰的最短紀錄為100公分，似乎達2至3歲的雌蛇已經適合懷孕，而根據某次紀錄一條雌性山蝰要誕下11條幼蛇約需時4.5小時。[3]
山蝰是相當容易飼養的蛇類，只需要一個小水盤與盒子作為棲息空間。山蝰幼蛇主要進食小型老鼠，成年山蝰則可選擇食用老鼠及鳥類。[3]不過也有許多山蝰是拒絕被餵食的，甚至有山蝰會絕食達五個月之久。[9]山蝰也會為飼養者構成一定的危機。[3]當飼養者要徒手拿起牠們時，它們懂得利用其下顎的長鉤狀尖牙，咬擊接觸者的手指。[4]
山蝰是亞洲最危險的毒蛇之一，成年山蝰的毒素分泌量幅度約由130至250毫克到150至250毫克乃至21至268毫克。在一項調查中顯示，十三條幼蛇（平均長度為79公分）的平均毒素分泌量則約有8至79毫克（中位數45毫克）。[3]
以老鼠為試驗品的LD50測試中，山蝰毒素對老鼠的靜脈注射LD50為0.08-0.31μg/g，腹膜注射為0.40μg/kg，皮下注射為4.75 mg/kg。山蝰的毒性主要由多種不同的毒素組成，當這些毒素分開被測試時，其毒性反應是偏向微弱的。而毒素的毒性亦會因應族群及所經歷的時間而有所變化。[3]
一般中毒後的徵狀主要由傷口疼痛開始，然後立即感受到腫脹。被咬傷中毒後出現流血亦是常見的徵狀，尤其在齒齦位置及分泌唾液時，更有機會出現血絲達20公鐘之久，這是由於血壓急降及心跳率減緩的原因所致；接著傷口所位處的肢體會出現起泡現象，表皮以至附近肌肉組織開始壞死，程度有時還可能相當嚴重。嘔吐、臉部腫大等徵狀也會隨機發生。[3] 劇痛會維持二至四週，時間因應肌肉受破壞的程度而定。而在被咬後的兩至三日內，不管是肢體還是軀幹都會是傷口腫脹的高峰階段。如果身體上出現腫脹達1至2個小時的話，這就屬於嚴重的中毒跡象。腫大的傷口附近亦有機會因為紅血球及血漿大量流失而出現血色褪去的現象。[16]當傷者在被咬後的十四天內不能接受有效救治的話，隨著呼吸系統及心臟的破壞，與及出現敗血症等情況，均會導致傷者死亡。[9]
由於山蝰的毒素能有效地誘發血液栓塞現象，因此一些醫療所曾對山蝰毒進行過活體外實驗，測試其對血液凝塊的功效。這種測試在西方命名為「稀釋山蝰毒素時間（Dilute Russell's viper venom time）」。實驗證明，毒素中的凝結劑直接催動了X因子，將V因子及磷脂中的凝血素轉化成凝血脢，稀釋的毒素能於23至27秒間產生凝結作用，確實是頗為有效的凝血劑。另外，在印度，有製作專門針對山蝰毒素的血清，以治療被山蝰咬傷時的中毒現象。[9]
根據一些文獻，山蝰尚有幾個有待確認的亞種，包括：[3]
對於山蝰的學名「D. russelii」，西方學者其實尚有不少的爭持。基於一些手笔之誤，「russelii」一詞曾受到多番質疑，因為發現山蝰的學者羅素（Russell），其名字應為「russelli」，但山蝰學名卻普遍被寫成「russelii」，當中只有一個「L」。故此有人表示傾向使用「russellii」，如趙爾宓等。
另外，山蝰這個單型屬日後可能會加入其它成員。學者奧貝斯特（Obst，1983）認為「Macrovipera lebetina」、「巴勒斯坦山蝰（英语：Vipera palaestinae）（Vipera palaestinae）與及「Vipera xanthina」均應列入山蝰屬中。學者格魯姆布里奇（Groombridge，1980，1986）曾根據支序分類學，透過巴勒斯坦山蝰與山蝰的一些共同特徵（如圓突的鼻端、頭部斑紋結構等）將二者的關係建構起來。學者力克等人（Lenk et al.，2001）亦從分子證據指出山蝰屬中不僅應包括巴勒斯坦山蝰，還應加入「Macrovipera mauritanica」及「Macrovipera deserti」。[3]
一些爬蟲學專家認為，由於山蝰生來擁有可怕的天賦及形象，是一種相當出色的蛇類，因而導致某些蛇類對牠的外貌作出模仿。當中糙鱗沙蚺（英语：Gongylophis conicus）（Gongylophis conicus）就是一個好例子，實際上牠本身並不是可怕的蛇類，然而卻有著與山蝰相當近似的色彩及紋理，也許是一種倚靠模仿能力自衛的特色。[3][8]
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山蝰屬（學名：Daboia，俗稱「七步紅」、「鎖鏈蛇」）是蛇亞目蝰蛇科蝰亞科下的一個單型屬，屬下有4種，而山蝰（D. russelii）為主要的一種有毒蛇類，主要分布於亞洲至印度次大陸地區、東南亞、中國南部及台灣。由於山蝰的分布範圍甚廣，因此被視為南亞區域最危險的蛇類之一，大部份遭蛇咬傷以及導致死亡的事件都與其有關。山蝰是印度著名四大毒蛇的其中一員，亦是引發印度境內幾乎所有人類遭蛇咬斃事故的元兇。山蝰的拉丁學名「D. russelii」來自最早發現山蝰的爬蟲學家柏德烈·羅素（Patrick Russell，1726-1805）博士；而其屬的學名「Daboia」則來自印地語，意指「潛伏者」。目前共已被確認有四個物種，其中圓斑蝰「Daboia siamensis」為台灣六大毒蛇之一。
Coluber Russelii Shaw & Nodder, 1797
Vipera elegans Daudin, 1903
Daboia elegans Gray, 1842
Daboia pulchella Gray, 1842
Vipera russelli Smith, 1943
ラッセルクサリヘビ（Daboia russelii）は、爬虫綱有鱗目クサリヘビ科Daboia属に分類されるヘビ。Daboia属の模式種[3]。
インド、パキスタン、スリランカ、ネパール、バングラデシュ[3]
模式標本の産地（基準産地・タイプ産地・模式産地）は、コロマンデル海岸（インド）[3]。
生息範囲は広いものの、その生息密度にはかなりの差がある。パキスタン東部及びインド北西部のパンジャブ地方、そこから西海岸に沿ってインド南部までの丘陵地帯、インド東部及びバングラデシュ西部のベンガル地方、スリランカ、そしてミャンマーでは生息密度が高く大きな被害が出ている。逆にミャンマー以外の東南アジアや中国、台湾では生息数に乏しく被害も希である。[4][5][要検証 – ノート]
全長は平均で120センチメートルで、最大で166センチメートルの記録がある。体色は褐色、黄褐色など変異が大きい。胴体には暗色の鎖状の斑紋が入る。
頭部は三角形で、尾は短い。
本種の毒は強烈で、人間にとっても致命的。毒性は出血毒および神経毒で咬まれると強烈な痛みでもがき苦しむことになる。 また、出血毒の作用から、助かっても後遺症が残る場合が多く、手足の切断に至るケースも少なくない。そのため、現地ではもっとも恐れられているヘビの一つ。
以前はDaboia属は本種のみで構成されていた（ラッセルクサリヘビ属）。2001年にミトコンドリアDNAのシトクロムbと16S rRNA分子系統推定からMacrovipera mauritanica・M. deserti（M. mauritanicaに含む説もある）・パレスチナクサリヘビVipera palaestinaeが本種と単系統群を形成するという解析結果が得られ、これらの種をDaboia属に含む説が提唱された[6]。 2007年にミトコンドリアDNAシトクロムbなどの分子系統推定から亜種D. r. siamensisとされていたベンガル湾以東の個体群（インドネシア、カンボジア、タイ、中華人民共和国、台湾、ミャンマー）を、遺伝的距離が大きいとして独立種D. siamensisに分割する説が提唱された[7]。
比較的開けた土地に生息する。中でも草原を好み、餌のネズミを追って人家近くや農地にも入り込む。夜行性だが、涼しい場合は日中でも活動する。動きは緩怠だが、突発的に素早く動くこともできる。危険を感じると体を膨らませ、噴気音をあげて威嚇する。
小型哺乳類、小型鳥類などを食べる。若い個体はトカゲなども食べる。そのため人との関わりが多く、咬まれる被害も多い。
繁殖様式は胎生。1回に20 - 63頭の幼蛇を産む。
1984年にインドの個体群がワシントン条約附属書IIIに掲載された[2]。
インドでは四大毒蛇として恐れられている。ちなみに他の三種は、カーペットバイパー、インドコブラ、アマガサヘビである。
頭部
この項目は、動物に関連した書きかけの項目です。この項目を加筆・訂正などしてくださる協力者を求めています（Portal:生き物と自然／プロジェクト:生物）。 
