Bothrops asper is responsible for the most deaths by venomous snakes in most of its geographic range. Often living close to humans in lowland areas and having highly-toxic venom results in a significant impact in the areas it inhabits. Its well studied venom is hemorrhagic, myonecrotic and proteolytic. It can cause incredible pain, necrosis of the region, and progressive edema.
Negative Impacts: injures humans (bites or stings, venomous )
Though well camouflaged, large, and venomous Bothrops asper has many predators, notably mussuranas (Clelia clelia). Mussuranas are snakes known to use their own venom and constrictive abilities to prey on other snakes. The blood of Clelia clelia contains an inhibitor of some the powerful toxins of the venom of terciopelos. Raptors, such as laughing falcons (Herpetotheres cacchinans), swallow-tailed kites (Elanoides forficatus), and crane hawks (Geranospiza caerulescens) are also important predators of terciopelos. The most effective are laughing falcons which can successfully defeat incredibly large female terciopelos.
Those less effective predators which can only feed on small to medium-sized terciopelos include mammalian predators such as hog-nosed skunks (Conepatus leuconotus), raccoons (Procyon lotor), and coatis Nasua nasua and Nasua narica. The more susceptible juveniles are preyed upon by many smaller raptors including roadside hawks (Buteo magnirostris). Some crabs, the spider Phoneutria, and tarantulas are suspected to prey on neonates.
Known Predators:
Anti-predator Adaptations: cryptic
Members of the genus Bothrops are distinguished by their broad, flattened heads which are set apart from the rest of the body. Their eye lids (canthus) are very distinct. In drier regions, terciopelos have more scales to prevent water loss. Bothrops asper varies greatly phenotypically across its geographic range. This has led to the confusion between it and other species, most notably Bothrops atrox, which is similar in color but often contains yellow or rust like tones and rectangular or trapezoidal blotches. The head of Bothrops asper is medium to dark brown or even black. It may have occipital botches or streaks that range from indistinct to distinct, but usually are absent. The underside is most often pale yellow. Individuals may weigh up to 6 kg and typically measure 1.2 to 1.8 m in length.
Like most other Bothrops, B. asper has different patterns and colors on its dorsal and ventral sides and also exhibits a postorbital stripe. The ventral side is yellow, cream, or a whitish gray, with dark blotches (mottling) that increases in frequency towards the posterior end. Ventrolaterally, the viper has alternating dark gray scales which are paler towards the medial line. Dorsally, the viper is olive, gray, brown, grayish brown, tan or at times nearly black. It has dark triangles with pale edges laterally, which range in number from 18 to 25. Apices either alternate or are reflective of each other over the middorsal line. In the interspaces, there are dark, paravertebral blotches. An individual may have a yellow zig-zag shaped line on each side of the body.
Terciopelos exhibit great sexual dimorphism. From birth, males are notably smaller in size than females. Females have thick, heavy bodies and can reach up to 10 times the size of males. Males have 161 to 216 ventral scales and 57 to 81 subcaudals. Females have 187 to 240 ventrals and 46 to 70 subcaudals. Juvenile females have a brown tail tip while males have a yellow tail tip. Prior to sexual maturation, males completely lose their yellow tip.
Range mass: 6 (high) kg.
Range length: 2.5 (high) m.
Average length: 1.2 to 1.8 m.
Other Physical Features: heterothermic ; venomous
Sexual Dimorphism: female larger; sexes colored or patterned differently
Recapture of the species is uncommon, so longevity in the wild is unknown. However, it is estimated that lifespan in the wild is similar to that in captivity, which ranges from 15 to 21 years based on zoo-keeping records.
Range lifespan
Status: captivity: 15 to 21 years.
Bothrops asper is primarily found in the tropical rainforest, the tropical evergreen forest, and the outer edge of savannas, but has also been found in a wide variety of other habitats including lowland and lower mountainous regions, dry regions of some tropical deciduous forests, and the cloud forests of Mexico. Bothrops asper prefers higher levels of humidity but adults may be found in desert areas as they are at less risk for dehydration than their juvenile counterparts. In Ecuador, Terciopelos inhabit the low montane wet and dry forests as well as the coastal cloud forests. Bothrops asper is known to move in to newly cleared agricultural land areas in many countries as well as the forested uplands in Trinidad. These vipers are mainly terrestrial, but some juveniles are known to climb trees. They have been documented at elevations from sea level to 2,640 m above sea level.
Range elevation: Sea Level to 2640 m.
Habitat Regions: tropical ; terrestrial
Terrestrial Biomes: desert or dune ; savanna or grassland ; forest ; scrub forest ; mountains
Aquatic Biomes: coastal
Other Habitat Features: agricultural
The range of Bothrops asper includes the northwestern coast of South America from Ecuador to Venezuela, Trinidad, and north as far as Mexico. More specifically, in Mexico and Central America Bothrops asper is found north to the Southern Tamaulipas and south to the Southeastern Yucatan Peninsula. It dwells in the lowland Atlantic coastal areas of Nicaragua, Costa Rica, and Panama. Terciopelos (Bothrops asper) are also found in the northern areas of both Guatamala and Honduras.
In South America these vipers are typically found west and north of the Andes, though there are exceptions, most notably in Venezuela where it can be found in the San Cristobal and Barquiseto Depressions in the Southeast region of the country. Bothrops asper is found on the Pacfic coastal plains and Andes Pacific versant from Columbia to as far south as the border of Peru and Ecuador. These snakes are also found in Northern Peru near the Pacific coast. In Columbia their range extends from the Pacific to the Carribean coastal plain as well as deeper within the country in the valleys of the Andes. Bothrops asper lives in sympatry with Bothrops atrox in central northern Columbia and certain areas of Venezuela. Bothrops atrox typically ranges further south in the Amazonian countries, but due to its similar appearance and overlapping distribution of Bothrops asper the snakes are often mistaken for one another. To further confusion, Bothrops asper was once considered a subspecies of B. atrox.
Biogeographic Regions: neotropical (Native )
Bothrops asper, due to its vast distribution, feeds on a wide variety of prey. The size, strength, and extremely toxic venom make terciopelos effective predators. In adult years, they have been known to feed on mammals, amphibians, and reptiles, but are not limited to these groups. Juveniles feed on small lizards and even large insects such as Scolopendra angulata.
In Costa Rica, adults have been known to feed on rats (Rattus rattus), opossums (Caluromys derbianus and Didelphis marsupialis), and other rodents, as well as rabbits (Sylvilagus brasiliensis), frogs (Lithobates forreri) and geckos (Gonatodes albogularis). In Ecuador they primarily feed on rodents. On the island of Trinidad, Bothrops asper has been known to feed on everything from rodents and other small mammals, lizards, frogs and birds, or even crayfish. These species include Didelphis marsupialis and Ninia atrata.
Animal Foods: birds; mammals; amphibians; reptiles; insects; aquatic crustaceans
Primary Diet: carnivore (Eats terrestrial vertebrates)
Bothrops asper has many parasites. Internal parasites include the nematodes Filaria, Rhabdias vellardi, Kalicephalus inermes, trematodes (Ochetosoma genus), and flatworms (Acanthocephala). Parasitic protozoans include hemogregarianes as well as amoeba and amoeba-like organisms. These have been known to cause gastroenteritis and hepatitis, among other illnesses. External parasites include several ticks, including Amblyoma savanae and Amblyoma dissimile, a known vector of hemogregarianes.
Terciopelos serve as prey to many species, and likely play a role in supporting local populations. Mussuranas, as well as many raptors including laughing falcons (Herpetotheres cacchinans), swallow-tailed kites (Elanoides forficatus), and crane hawks (Geranospiza caerulescens) prey upon terciopelos. Predators that prey on small terciopelos include mammalian predators such as hog-nosed skunks (Conepatus leuconotus), the coatis Nasua nasua and Nasua narica and racoons (Procyon lotor). Juveniles are preyed upon by many smaller raptors including roadside hawks (Buteo magnirostris). Some crabs and tarantulas prey on neonates.
Bothrops asper are also important predators in their ecosystems and thus impact local populations of prey species as well. Juveniles feed on small lizards and even large insects such as Scolopendra angulata. Adults feed on rats (Rattus rattus), opossums (Caluromys derbianus and Didelphis marsupialis), and other rodents, as well as rabbits (Sylviagus brasiliensis), frogs (Lithobates forreri) and geckos (Gonatodes albogularis).
Commensal/Parasitic Species:
Terciopelos feed on small rats and other seed eaters which are detrimental to farmers. The venom has potential pharmacological implications and continues to be of promise.
Positive Impacts: source of medicine or drug ; controls pest population
Bothrops asper is viviparous, making development to the neonatal/juvenile state internal.
Urbanization, deforestation, contamination, and agriculture have resulted in the declining number of Bothrops asper in Ecuador. In spite of this, some are able to live and even thrive in open and suburban zones. It has been suggested that the Ecuadorian B. asper be placed as a species of "Least Concern" on the IUCN Redlist, though the species is currently not evaluated.
In Costa Rica, human impact has seemed to favor Bothrops asper. Terciopelos have been able to prosper in certain agricultural fields such as banana, cacao and coffee. Even though they are adaptable, some areas have seen a decline which is thought to stem from more drastic environmental changes and decline of prey.
CITES: no special status
Communication and perception is not well studied in Bothrops asper. However, the species is named for its loreal heat-sensing pit which it uses at night to detect prey. Males follow females to show they are interested in mating, and will exhibit head-bobbing motions if the female allows him to approach.
Like all snakes, Bothrops asper perceives its environment through visual, infrared, tactile, and chemical stimuli.
Communication Channels: visual
Perception Channels: visual ; infrared/heat ; tactile ; chemical
Common Names: Terciopelos, barbas amarillas, fer de lance, cola de hueso, rabo de hueso, cola blanca, yellow-jaw tommygoff, cuatronarices, equis, cachete de punica, cascabelle, among many others.
Unlike many vipers, there are no documented cases of male-male combat in Bothrops asper. Often females will mate with more than one male in a mating season. Mating includes a series of movements of the male who then slowly chases an accepting female. He often bobs his head at her side. The female then stops movement and extends her posture to mate. It is not known whether this species exhibits annual or biennial reproduction.
Mating System: polyandrous
Bothrops asper is considered the most prolific snake in all of the Americas. It breeds seasonally, usually during the rainy season when food is readily available. Males are known to follow females during the mating season in some regions. Fertilization is internal. Because terciopelos have a large geographic range, the time and length of reproduction varies greatly. For instance, in the Atlantic population of Costa Rica, B. asper mates in March, but in the Pacific region, it mates from September to November. This variation continues throughout Central and South America. There is a positive correlation between the body size of the female parent and the number of offspring she produces. After a gestation period of 6 to 8 months, females give birth to 5 to 86 viviparous young. These young terciopelos weigh between 6.1 and 20.2 grams each. There is also some evidence of long term sperm storage by the females to delay fertilization. Females are 110 to 120 cm at sexual maturity, while males average at 99.5 cm.
Breeding interval: Bothrops asper breads once yearly.
Breeding season: Breeding season for Bothrops asper varies. Some populations are known to mate in March, and give birth in September-November. Others mate from September to November and parturition occurs from April to June.
Range number of offspring: 5 to 86.
Range gestation period: 6 to 8 months.
Key Reproductive Features: iteroparous ; seasonal breeding ; sexual ; viviparous ; sperm-storing ; delayed fertilization
Females build up fat stores which lead to a release in hormones that stimulate ovulation. Females gestate for 6 to 8 months before giving birth to live young. There is no parental care.
Parental Investment: pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female)
Terciopelo
Fer-de-lance
Atlantic lowlands of eastern Mexico and Central America (Guatemala, Belize, Honduras, Nicaragua, Costa Rica and Panama) and northern South America (Colombia and Venezuela). A disjunct population occurs in southeastern Chiapas (Mexico) and southwestern Guatemala (McDiarmid et al. 1999).
Holotype: MCZ R2718 (McDiarmid et al. 1999).
Type-locality: "Obispo, on the Isthmus of Darien" [Panama].
Terciopelo (Bothrops asper) [note 1] is a species of pit viper found at low to moderate elevations in northeast Mexico and Central America, and into South America where it is known from elevations up to 2600 meters in the Colombian and Ecuadorian Andes, as well as into Venezuela.[3] With a mass of up to 6 kilograms (13 lb) and a maximal length of 2.5 metres (8.2 ft), the terciopelo is among the largest pit vipers. It is light to dark brown in color, often with yellow zig-zag-shaped lines on each side of the body. Dubbed "the ultimate pit-viper" for its large size, fangs and venom yield, it has a fearsome reputation, responsible for the most snakebites within its range because of its defensive temperament and proximity to human residence.[2] However, like other venomous snakes, it avoids confrontation with humans whenever possible. No subspecies are currently recognized.[6]
The generic name, Bothrops, comes from the Greek words bothros and ops, which mean 'pit' and 'face' (or 'eye'), respectively. This is a reference to these snakes' highly sensitive heat-detecting pit organs. The specific epithet, asper, which is a Latin word meaning 'rough' or 'harsh', may allude to the species' keeled dorsal scales.[7]
Some of the common names applied to this snake are terciopelo ("velvet" in Spanish), fer-de-lance,[3] mapepire balsain (Trinidad), carpet labaria (Guyana), barba amarilla (Guatemala, Honduras, Nicaragua; "yellow beard"), equis (Ecuador and Panama; "x"),[8] talla equis , mapaná (Colombia), cuaima (Venezuela), nauyaca (México; from Nahuatl nahui, four, and yacatl, nose; "four noses"),[9] and yellow-jaw tommygoff (Belize)."
The name fer-de-lance is French (or possibly Créole), translating to "iron of the lance", "iron spear point" or simply "spearhead" or "lancehead".[10][11] In English the name lancehead is applied to the genus Bothrops as a whole,[3][10][12][5] and in combination with the majority of the species within the genus (e.g.: Alcatrazes lancehead (Bothrops alcatraz), Patagonian lancehead, (Bothrops ammodytoides), Andean lancehead (Bothrops andianus) etc.).[3] The name fer-de-lance has been used inconsistently and very informally with several species in the genus Bothrops having been called fer-de-lance at one time or another, most commonly Bothrops asper, Bothrops atrox, Bothrops caribbaeus, and Bothrops lanceolatus.[3][13][14] Several herpetologists have preferred and argued to restrict the name fer-de-lance to the Martinique lancehead (Bothrops lanceolatus) from the Caribbean Island of Martinique, but popular usage has rarely recognized any distinction.[10] In their seminal opus on the venomous reptiles of the Western hemisphere, Campbell & Lamar stated: "The name fer-de lance, widely used in North America with reference to B. asper and B. atrox, has no legitimate origin of use in regions inhabited by this snake."[3] In an effort to establish standardized names for the amphibians and reptiles of North America, the Society for the Study of Amphibians and Reptiles (SSAR), a not-for-profit organization and one of the largest international herpetological societies, applied the following nomenclature:[4][5]
In recent decades, herpetologists have preferred the name 'terciopelo' for Bothrops asper,[15][16][17][18] although the term fer-de-lance is still common in popular usage.
Bothrops species can be distinguished by their broad, flattened heads which are set apart from the rest of their bodies. The head of this snake is light to dark brown or even black. Although usually absent, it may have occipital blotches or streaks that range from indistinct to distinct. The underside is most often pale yellow. This species has different patterns and colors on its dorsal and ventral sides and it exhibits a postorbital stripe. The ventral side is yellow, cream, or a whitish gray, with dark blotches that are more frequent closer to the posterior end. Ventrolaterally, B. asper has interchanging gray scales which are more pale towards the medial line. Dark triangles with pale edges can be seen laterally, which range in number from 18 to 25. Apices either alternate or are reflective of each other over the middorsal line. In the interspaces, there are dark, paravertebral blotches. Specimens may have a yellow zig-zag-shaped line on each side of the body. There is a great variety of colours on its dorsal side: olive, gray, light brown to dark brown, tan or sometimes nearly black. To prevent water loss where they occur in drier regions, this species has more scales.[3]
Specimens of this species may weigh up to 6 kilograms (13 lb) and are often 1.2 to 1.8 meters (3.9 to 5.9 ft) in length. Very big females can reach lengths up to 2.5 metres (8.2 ft), although this is uncommon.[3][19] These are among the most sexually dimorphic of all snakes. The two sexes are born the same size, but by age 7 to 12 months, females begin to grow at a much faster rate than males. Females have thick, heavy bodies and grow significantly larger than males.[3] They also have heads two or three times the size of males relative to their size and proportionally bigger fangs (typically 2.5 cm), as well.[20]
Across its geographic range, this species varies greatly phenotypically. As a result, great confusion between it and other related species, most notably Bothrops atrox, which is similar in color but usually has yellow or rust-like tones and rectangular or trapezoidal blotches.[3]
It is found on the Gulf - Atlantic versant of eastern Mexico as far north as the state of Tamaulipas, southward through the entire Yucatán Peninsula extending into Central America, including Guatemala, Belize, Honduras, Nicaragua, Costa Rica and Panama. An isolated population occurs in southeastern Chiapas (Mexico) and southwestern Guatemala. In northern South America, it is found in Colombia, Ecuador, Guyana and Venezuela. The type locality given is "Obispo, on the Isthmus of Darien" (Panama).[2][21]
This is mostly a lowland species that, in Mexico and Central America, occurs from about sea level to 1,200 to 1,300 meters (3,900 to 4,300 ft) altitude. In South America, it apparently ranges to considerably higher elevations: up to 2,500 metres (8,200 ft) in Venezuela and at least 2,640 metres (8,660 ft) in Colombia according to herpetologist Lancini.[3]
According to Campbell and Lamar (2004), its range in Ecuador extends as far south along the Pacific coast as El Oro Province and the Vilcabamba area of the Río Catamayo Valley.[3] This species is reported to occur from seven (Bolívar, Carchi, Chimborazo, Esmeraldas, Guayas, Los Ríos and Pichincha) of the fourteen provinces along the Pacific slope of Ecuador. There are even a few records from northern coastal Peru, with these snakes being reported in the Tumbes Region.[22] It is also known from the island of Gorgona off the Pacific coast of Colombia.[3]
B. asper occurs throughout the inter-Andes valleys of Colombia across the Caribbean coastal plain through central Venezuela north of the Orinoco as far east as the Delta Amacuro region. This is the only Bothrops species that occurs on the island of Trinidad, although the situation there is complicated due to proximity of Trinidad to the Orinoco Delta where it may be sympatric with B. atrox.[3]
Due to the casual and informal application of the name "Fer-de-lance" being applied to any number of species of Latin America pit vipers in the genus Bothrops, there is much confusion and misunderstanding, particularly in popular literature, as to proper nomenclature. Populations of Bothrops often referred to as Fer-de-lance on the island of Saint Lucia are Bothrops caribbaeus. Populations of Bothrops referred to as Fer-de-lance on the island of Martinique are regard as Bothrops lanceolatus.[13][14]
This species likes moist environments, and occurs in most life zones located at low or middle elevations (up to 600 metres (2,000 ft)), excluding those with strong seasonal dry periods. They are, however, sometimes found at much higher elevations. This is true in the premontane forest in Costa Rica, the cloud forest of Guatemala and Mexico, or the lower montane wet forest in the Caribbean Region of Colombia and Ecuador. It chiefly inhabits tropical rainforest and evergreen forest, but it also occurs in drier areas of tropical deciduous forest, thorn forest and pine savannah near lakes, rivers and streams. The home range of B. asper averages between 3.71 ha and 5.95 ha, which is comparatively small in relation to other pitvipers.[23]
B. asper is nocturnal and solitary. It is less active in colder and drier periods. This species is often found near rivers and streams, basking in the sun during the day and lying still while well camouflaged in leaf litter or under forest cover waiting to ambush prey such as rats and mice that come within range during the night. When cornered or threatened, this species can be very defensive and may exhibit an S-coiled defense display. Juveniles are often semiarboreal, and even adults are sometimes encountered in bushes and low trees. Juveniles are also known to exhibit caudal luring, a use of their differently colored tail tips to lure prey.[3] Although both males and females display this behavior, only males have bright coloured tail tips.[24]
Compared to the common lancehead, B. atrox, these snakes have been described as excitable and unpredictable when disturbed. They can, and often will, move very quickly,[3] usually opting to flee from danger,[20] but are capable of suddenly reversing direction to vigorously defend themselves. Adult specimens, when cornered and fully alert, are dangerous. In a review of bites from this species suffered by field biologists, Hardy (1994) referred to it as the "ultimate pit viper".[3]
Bothrops asper is a diet generalist and is known to prey on a remarkably wide range of animals. A generalized ontogenetic diet shift occurs, with a higher percentage of ectothermic prey in juveniles, changing to a greater percentage of endothermic prey in adults, particularly small mammals. However both juveniles and adults, regardless of size or age, are known to opportunistically prey on ectothermic and endothermic species. Reports of invertebrate and insect remains in the digestive tracts along with frog and lizard remains are believed to represent secondary ingestion, however the dissection of several specimens containing only insect remains such as beetles (Coleoptera), and bugs (Hemiptera) are believed to reflect insects as primary prey too. Cannibalism has been reported in both captive and wild juveniles and the species is known to scavenge on dead frogs and rodents.[21]
Just a few of the documented ectothermic prey items include: centipedes (Scolopendra), beetles (Coleoptera), grasshoppers (Orthoptera), crayfish, eels (Synbranchus); caecilians (Dermophis), frogs (Eleutherodactylus, Leptodactylus, Lithobates, Smilisca), toads (Rhinella), amphisbaenians (Amphisbaena), lizards (Ameiva, Anolis, Ctenosaura, Gonatodes), and snakes (Bothrops, Erythrolamprus, Ninia). Endothermic prey species include: bay wren (Cantorchilus nigricapillus), grey-headed tanager (Eucometis penicillata), wren (Troglodytes), blue-black grassquit (Volatinia jacarina), Central American woolly opossum (Caluromys derbianus), common opossum (Didelphis marsupialis), Desmarest's spiny pocket mouse (Heteromys desmarestianus), dusky rice rat (Melanomys caliginosus), black rat (Rattus rattus), Rothschild's porcupine (Coendou rothschildi), Brazilian cottontail (Sylvilagus brasiliensis), and least shrew (Cryptotis parva).[21][25]
The timing of the reproductive cycle and the litter size of this species vary according to location: in some parts of Costa Rica, for example, it is more prolific than in others. Reproduction is highly seasonal and in Costa Rica, reproductive cycles are tightly related to rainfall patterns. The timing of breeding differs between populations in the Caribbean and Pacific lowlands. On the Pacific side, mating took place between September and November, with females giving birth between April and June. The average number of offspring was 18.6 (five to 40) in this population. Neonates ranged in total length from 28 to 34.6 centimeters (11.0 to 13.6 in) and in weight from 6.7 to 13.1 grams (0.24 to 0.46 oz). On the Atlantic side, mating was observed in March, and births occurred between September and November. The average number of offspring was 41.1 (14–86), whereas the total length of neonates ranged from 27 to 36.5 centimeters (10.6 to 14.4 in), and weighed from 6.1 to 20.2 grams (0.22 to 0.71 oz). In both populations, gestation time ranged from six to eight months, and the size of a litter correlated significantly with the size of the female.[26] This species is considered to be the most prolific of all snakes in the Americas.[3]
Male-male combat in this species has not been observed. Females will mate with more than one male during mating season. Mating includes a series of movements of the male, which then slowly chases an accepting female. The female then stops movement and extends her posture to mate. It is not known whether this species exhibits annual or biannual reproduction.[23]
B. asper, together with Crotalus durissus, is the leading cause of snakebite in Yucatán, Mexico.
It is considered the most dangerous snake in Costa Rica, responsible for 46% of all bites and 30% of all hospitalized cases; before 1947, the fatality rate was 9%, but this has since declined to almost 0% (Bolaños, 1984), mostly due to the Clodomiro Picado Research Institute,[28] responsible for the production of snake antiophidic sera (which are also exported to other countries in Latin America and Africa) and scientific research on serpents and their venoms, as well as educational and extension programs in rural areas and hospitals.
In the Colombian states of Antioquia and Chocó, it causes 50–70% of all snakebites, with a sequelae rate of 9% and a fatality rate of 6% (Otero et al., 1992).
In the state of Lara, Venezuela, it is responsible for 78% of all envenomations and all snakebite fatalities (Dao-L., 1971). One of the reasons so many people are bitten is because of its association with human habitation; many bites occur indoors (Sasa & Vázquez, 2003).
Herpetologist Douglas March died after being bitten by this species.[29]
This species is irritable and fast-moving. It is also regarded as being more excitable and unpredictable than B. atrox. Its large size and habit of raising its head high off the ground can result in bites above the knee. It has also been observed to eject venom over a distance of at least 6 ft (1.8 m) in fine jets from the tips of its fangs (Mole, 1924).[29]
Bite symptoms include pain, oozing from the puncture wounds, local swelling that may increase for up to 36 hours, bruising that spreads from the bite site, blisters, numbness, mild fever, headache, bleeding from the nose and gums, hemoptysis, gastrointestinal bleeding, hematuria, hypotension, nausea, vomiting, impaired consciousness and tenderness of the spleen. In untreated cases, local necrosis frequently occurs and may cause gangrene which often requires amputation. In 12 fatal cases, the cause of death was sepsis (5), intracranial hemorrhage (3), acute kidney injury with hyperkalemia and metabolic acidosis (2) and hemorrhagic shock (1).[29]
Venom yield (dry weight) averages 458 mg, with a maximum of 1530 mg (Bolaños, 1984)[29] and an LD50 in mice of 2.844 mg/kg IP.[20]
The venomous bite of B. asper has been suggested to have been a factor in the choice of certain Mayan settlements, such as Nim Li Punit, Belize Central America, where the thick jungle inhabited by these snakes was used as a defensive boundary.[30]
The venom of the fer-de-lance is so potent that didelphine opossums (i.e., opossums like the Virginia opossum), which are normally immune to the venom of pit vipers and rattlesnakes, are still capable of succumbing to the venom of this snake. This is especially the case if the opossum is not fully grown (and thus the venom is more concentrated per gram). Indeed, the extremely potent venom of B. asper has been suggested to have evolved as part of an evolutionary arms race between these snakes and didelphine opossums, as a defensive adaptation to prevent predation by opossums, an adaptation that allowed fer-de-lances to prey on large opossums, or both.[31]
This species was once regarded as a subspecies of B. atrox and can still often be confused with it.[20]
Goliath birdeater spiders sometimes prey on the snake, despite it being one of the most venomous snakes in Central and South America.[32]
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{{cite book}}: CS1 maint: multiple names: authors list (link) Terciopelo (Bothrops asper) is a species of pit viper found at low to moderate elevations in northeast Mexico and Central America, and into South America where it is known from elevations up to 2600 meters in the Colombian and Ecuadorian Andes, as well as into Venezuela. With a mass of up to 6 kilograms (13 lb) and a maximal length of 2.5 metres (8.2 ft), the terciopelo is among the largest pit vipers. It is light to dark brown in color, often with yellow zig-zag-shaped lines on each side of the body. Dubbed "the ultimate pit-viper" for its large size, fangs and venom yield, it has a fearsome reputation, responsible for the most snakebites within its range because of its defensive temperament and proximity to human residence. However, like other venomous snakes, it avoids confrontation with humans whenever possible. No subspecies are currently recognized.
