Blue Shark

Maximum longevity: 20 years (wild)

Blue sharks in the wild have an average lifespan of 15 to 16 years. Blue shark life expectancy decreases to an average of 8 years when held in captivity, likely due to their inability to engage in their pelagic and migratory lifestyle.

Range lifespan
Status: wild: 20 (high) years.

Range lifespan
Status: captivity: 8 (high) years.

Average lifespan
Status: wild: 15 years.

Typical lifespan
Status: captivity: 8 (high) years.

Aside from predation by humans for the lucrative shark fin trade, blue sharks are not frequently preyed upon. Occasional predators can include larger sharks such as shortfin makos Isurus paucus and great whites (Carcharodon carcharias), as well as killer whales Orcinus orca, while juveniles can also be taken by California sea lions (Zalophus californianus).

Due to their pelagic lifestyle, blue sharks exhibit countershading. The lighter coloration on the ventral surface helps to camouflage the sharks against the background of lighter-colored water when viewed from below. In contrast, the darker shades of blue and silver on the dorsal side allows them to blend in with the depths below when viewed from above. This countershading, along with a streamlined body shape, allows blue sharks to maneuver both swiftly and unnoticed as both predator and prey.

Known Predators:

• short fin mako sharks (Isurus paucus)
• great white sharks (Carcharodon carcharias)
• orcas (Orcinus orca)
• California sea lions (Zalophus californianus)
• humans (Homo sapiens)

Anti-predator Adaptations: cryptic

The striking coloration of blue sharks makes them one of the most distinctive species in the family Carcharhinidae (requiem or whaler sharks). The dorsum is a deep shade of indigo, while the flanks are a vibrant blue. The ventral surface fades to a light grey, exhibiting the typical pelagic countershaded coloration that deceives the eyes of bottom-dwelling prey or predators by blending in with light coming from the sun. The body is streamlined and thin, with an elongated heterocercal caudal (tail) fin, making it one of the fastest sharks in the ocean. The second dorsal fin is approximately half the size of the first, and the pectoral fins are proportionately longer than in most other shark species. The eyes are large, and the mouth is lined with several rows of triangular, serrated teeth; each tooth is usually replaced every 8 to 15 days. Blue sharks can reach 4 m in total length and weigh up to 240 kg.

Range mass: 240 (high) kg.

Range length: 4 (high) m.

Average length: 3.35 m.

Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry

Sexual Dimorphism: female larger

Blue sharks inhabit the epipelagic and mesopelagic zones (from the surface to about 350 m in depth), in water temperatures ranging between 12 and 20°C. While they are mainly found in pelagic, open-ocean waters, they may sometimes be found closer to shore in the neritic zone, near the edge of continental shelves.

Range depth: 0 to 350 m.

Habitat Regions: temperate ; tropical ; saltwater or marine

Aquatic Biomes: pelagic

Blue sharks are one of the most wide ranging shark species and can be found in all major oceans (except the Arctic), as well as the Mediterranean Sea and in temperate and tropical pelagic waters.

Biogeographic Regions: indian ocean (Native ); atlantic ocean (Native ); pacific ocean (Native ); mediterranean sea (Native )

Other Geographic Terms: cosmopolitan

Blue sharks prey on up to 24 species of cephalopods and 16 species of fish. They primarily feed upon non-active, gelatinous, mesopelagic/bathypelagic cephalopods such as blanket octopus (genus Tremoctopus), bathyscaphoid squids (family Cranchiidae), and pelagic octopus (Ocythoe tuberculata). Prey also includes small schooling fishes, such as long-snouted lancetfish (Alepisaurus feroxe), snake mackerel (Gempylus serpens), and castor oil fish (Ruvettus pretiosus). During their reproductive migration cycles off of the coast of Brazil, blue sharks were found to have consumed seabirds, including great shearwaters (Puffinus gravis).

Animal Foods: birds; fish; mollusks

Primary Diet: carnivore (Piscivore , Molluscivore )

Blue sharks are top-level predators that help to regulate prey populations in the marine pelagic environment.

Pilotfish (Naucrates ductor) have a mutualistic symbiosis with blue sharks. They clean the shark's teeth and gills and removes any parasitic species that have attached themselves to the shark's skin. In return, pilotfish gain protection from predators and a ready source of food.

Many species of copepods are found on the gills and outer skin of blue sharks. Several tapeworm and one nematode species have been found in the stomach and spiral valve of blue sharks, resulting from consumption of infected fish that are the intermediate hosts of these parasites.

Mutualist Species:

• pilot fish (Naucrates ductor)

Commensal/Parasitic Species:

• Kroyeria carchariaeglauci (Subclass Copepoda, Subphylum Crustacea)
• Kroyeria lineata (Subclass Copepoda, Subphylum Crustacea)
• Pandarus floridanus (Subclass Copepoda, Subphylum Crustacea)
• Phyllothereus cornutus (Subclass Copepoda, Subphylum Crustacea)
• Echthrogaleus sp. (Subclass Copepoda, Subphylum Crustacea)
• Anisakis simplex (Family Anisakidae, Phylum Nematoda)
• Anthrobothrium laciniatum (Class Cestoda, Phylum Platyhelminthes)
• Pelichnibothrium speciosum (Class Cestoda, Phylum Platyhelminthes)
• Platybothrium auriculatum (Class Cestoda, Phylum Platyhelminthes)
• Prosobothrium armigerum (Class Cestoda, Phylum Platyhelminthes)

Although mainly caught indirectly as bycatch on long lines and in gill nets, blue sharks, like many shark species, are valued commercially for their fins, squalene (liver oil), skin, cartilage, and their teeth and jaws. Their meat is less valued because of its high ammonia content.

Positive Impacts: food ; body parts are source of valuable material

Blue sharks are considered by commercial fishermen (particularly those of mackerel, pilchard, and salmon) to be a nuisance species, as they prey on target species and ruin nets by becoming entangled in them.

Due to their pelagic lifestyle, blue sharks are not often encountered by divers and swimmers. They are considered to be a dangerous species, however, with the International Shark Attack File recording a dozen confirmed, unprovoked attacks (4 fatal), and nearly two dozen additional, provoked attacks.

Negative Impacts: injures humans (bites or stings)

After fertilization, embryos develop inside the female's uterus, nourished by a placenta-like yolk sac. Females give birth to fully-developed, live young. Blue sharks have one of the fastest growth rates of all sharks, growing up to 30 cm annually until maturity. Blue sharks are 35to 50 cm in length at birth, and will grow up to 400 cm (although the average length is 335 cm). Both sexes reach adulthood at about 220 cm in length. Juveniles usually stay in pupping areas of the sub-Arctic boundary (42°N North Pacific Ocean) until they reach maturity at 5 years of age.

Development - Life Cycle: indeterminate growth

Although not usually a targeted species, blue sharks are caught as bycatch by longline and dragnet fishing fleets, and to a lesser extent by sport fishermen. International conservation projects have been implemented to decrease the harvest of pelagic sharks, including this species. In 1991, the Australian Government implemented legislation that banned Japanese longline fishing fleets from taking shark fins without their attendant carcasses. Canada issued a fishery management plan for shark species in 1995 that established catch limits of 250,000 kg for blue sharks, and implemented limitations on finning and gear use, licenses, areas and seasons, and bycatch limits. Management plans have been in place in the US since 1993. Proper licensing and commercial quota limits have been introduced, and finning has also been banned within the US Exclusive Economic Zone. However, exploitation by the shark finning industry has still decreased populations globally, and the IUCN lists this species as "Near Threatened".

US Federal List: no special status

CITES: no special status

State of Michigan List: no special status

IUCN Red List of Threatened Species: near threatened

Most sharks are known to use body language to signal aggression, but there is little data available on whether sharks utilize other forms of communication between individuals. Like all sharks, blue sharks have highly developed senses of smell, sight, and touch. The lateral line is a sensory organ running down the length of their body that detects pressure waves from movements in the water, allowing the sharks to perceive movements of prey. They also possess electroreceptors called Ampullae of Lorenzini on the underside of the snout, which detect electrical fields generated by the muscle contractions of prey items.

Communication Channels: visual

Perception Channels: visual ; tactile ; acoustic ; vibrations ; chemical ; electric

Blue sharks congregate together on continental shelves during the summer. Mating begins when a male bites a female between her first and second dorsal fins. For this reason, the skin over most of a female's dorsum may be up to three times as thick as in males. Insemination occurs via insertion of one of the claspers into the female's urogenital opening. Pair bonding does not occur, and after mating, individuals separate.

Mating System: polygynandrous (promiscuous)

Males reach sexual maturity at 187 cm in length, while females become mature at 220 cm. It is not definitively known if females breed every year and deposited sperm may be stored within the female's oviductal gland for several months after mating. Once pregnant, females migrate north to birthing and pupping grounds in the sub-Arctic boundary. Gestation lasts from 9 to 12 months, and up to 130 pups in a litter have been documented, but 25 to 50 pups are born on average. Pups average 39 cm at birth. Unlike bony fish, sharks utilize internal fertilization. The male bites down and insert a clasper inside the female to transfer sperm. Females have thick skin to protect them from injury when the males bite them during mating. Blue sharks are viviparous.

Breeding interval: It is unknown whether female blue sharks breed annually, or less frequently.

Breeding season: In the northern Pacific, most births occur from December to April.

Range number of offspring: 25 to 130.

Range gestation period: 9 to 12 months.

Range age at sexual or reproductive maturity (female): 5 to 6 years.

Range age at sexual or reproductive maturity (male): 5 to 6 years.

Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (Internal ); viviparous ; sperm-storing ; delayed fertilization

As in other viviparous species, female blue sharks provide nourishment and protection to their young as they develop. After birth, shark pups separate from their mother and have no further contact.

Parental Investment: female parental care ; pre-hatching/birth (Provisioning: Female, Protecting: Female)

Blue sharks are viviparous, giving birth to live young after a gestation period of nine to twelve months (6) (7). Up to 135 pups can be born per litter, partially depending on the size of the female, but the average is 25 to 50 (5) (6). Maturity is reached at approximately five to six years old and blue sharks are known to have lived to 20 years (7). Although often observed cruising slowly and sluggishly the blue shark is capable of rapid movement if it is excited or feeding (6). This species will often circle its prey before moving in to attack it. Blue sharks primarily feed upon relatively small prey, such as bony fish and squid, but will also take larger prey including mammalian carrion (1).

International obligations that regulate the fishing of sharks include the Code of Conduct for Responsible Fishing of the Food and Agriculture Organisation (FAO) of the United Nations, the International Plan of Action for Sharks (IPOA-SHARKS), the United Nations' Agreement on Straddling Stocks and Highly Migratory Species, and the Sustainable Fisheries Act. Although some countries have banned finning, there are no binding international treaties for the management of sharks, including the regulation or outlawing of finning (9). The blue shark is listed on Annex I of the 1982 Convention on the Law of the Sea (3), which stresses the need for international cooperation in the conservation, management and utilization of living aquatic resources, especially of migratory species. This does not, however, enforce any regulations (9). Fortunately, the blue shark is a prolific species with good rebound potential, and the abundance and wide distribution of this species offers a reasonable buffer against extinction (7).

The blue shark is easily identified by its beautifully coloured slender body, which is a deep indigo-blue across the back, shading to a vibrant blue on the sides, and paling to white underneath (4). This shark has large eyes, triangular teeth, a conical snout, long pectoral fins and a second dorsal fin much smaller than the first (2) (4). While its elongated caudal fin provides swimming power, its sleek, tapered body makes it a graceful mover (5).

The blue shark is a pelagic species occurring in the open ocean near the surface, inhabiting slightly deeper, cooler waters when in tropical environments (4). Although typically an offshore species, the blue shark may venture inshore, especially at night (1).

Blue sharks are probably the most wide-ranging and (at least initially) one of the most abundant of all shark species, occurring in temperate and tropical waters from 50°N to 40°S around the globe (2). A migratory species, they periodically travel clockwise around the Atlantic, seemingly riding the Gulf Stream to Europe, taking various currents down the European and African coasts, and riding the Atlantic North Equatorial Current to the Caribbean region (1).

Classified as Lower Risk / Near Threatened (LR/nt) on the IUCN Red List (1).

Although blue sharks are among the most abundant, widespread, fecund and faster growing of the sharks, they are one of the most heavily fished sharks in the world. With an estimated 10 to 20 million individuals caught and killed each year, there is concern not only about what this is doing to blue shark populations, but also about the effect the removal of such an important predator might be having on the oceanic ecosystem (1). Blue sharks are one of the most important species in the international shark fin trade. However, their meat, while eaten in a few countries, is not very popular (8). They are also an important angling species in some areas (1).

The heaviest Blue Shark weighed 862LB.

This common oceanic shark is usually caught with pelagic longlines but also hooks and lines, pelagic trawls, and even bottom trawls near coasts. Catches for the blue shark have been reported to FAO only from area 27 (Northeast Atlantic); countries reporting, since 1978, are mainly France (with a peak of 358 t in 1994) and Denmark (only a few metric tons). The total catch reported for this species to FAO for 1999 was 3 199 t. The countries with the largest catches were Spain (2 233 t) and New Zealand (593 t). It is utilized fresh, smoked, and dried salted for human consumption; its hides are used for leather; fins for shark-fin soup base; and also for fishmeal and liver oil. This shark is also considered a game fish and taken by sports anglers with rod and reel. The blue shark is the most widespread oceanic shark and has a great overall abundance. It is a very common bycatch in high-seas longline and driftnet fisheries but it is not a very valuable shark, so mostly only the fins are taken. However, there are some countries that readily consume blue sharks such as Spain, Brazil, Italy, and France (Bonfil 1994, Stevens in press c). This species is the most popular shark in sport fisheries in the US (Hoff and Musick 1990) and is likely taken by recreational fishermen throughout the world. There are no reliable statistics for the catches (directed or incidental) of blue sharks around the world and this makes difficult to understand the impact of fisheries on the stocks. Bonfil (1994) made some rough calculations based on reported catch rates in the literature and estimated that the high-seas longline and driftnet fisheries of the late 1980s could have taken some 6.2-6.5 million blue sharks annually. Matsunaga and Nakano (1996) compare changes over time of CPUE data in two areas of the Pacific (0-10° N and 10-20° N) and find no significant changes in blue shark abundance. Nakano (1996) detected a 20% decrease in Japanese longline CPUE for blue sharks in the North Pacific but no trend in other areas of the world. The only known assessment of the impact of high seas fisheries on blue shark stocks was done by Nakano and Watanabe (1992). These authors concluded that the catch levels in the late 1980s had no significant impact on the blue shark populations of the North Pacific. However, other authors (Anon. 1992, Wetherall and Seki 1992) consider that appropriate information is lacking for such an assessment. In the United States, blue sharks were an important bycatch during the development of the California swordfish/thresher shark driftnet fishery but the total numbers killed were relatively low (Cailliet et al 1993). Off the U.S. Atlantic coast, blue shark catch rates from pelagic longline logbook data decreased sharply in the first 3 years of data available but remained without trend since 1989 (Cramer 1998). In contrast to this, standardised catch rates for the sport fishery of Virginia-Massachusetts showed an increasing trend over the same period (Brown 1998). This conflicting information suggests likely errors in the above data. Canada started an experimental fishery for blue sharks off its Atlantic coast in the early 1990s. This fishery has a 225 t TAC (Mooney-Seus and Stone 1996). Conservation Status : The blue shark is a prolific species with an intrinsic rebound potential that is above the average of 26 species analysed by Smith et al. (1998). The IUCN Red List classifies blue shark as a Lower Risk/Near Threatened species at the world level (Camhiet al. 1998). The high abundance and worldwide distribution of this species offers a relative buffer against extinction. However, some discrete stocks might become threatened in the future if bycatch in high seas fisheries does not come under strict monitoring and control. Fortunately, efforts towards alleviating the lack of monitoring data are currently being taken by multiple regional tuna fisheries organisations around the globe. Additional information from IUCN database Additional information from CITESdatabase

A wide-ranging, oceanic-epipelagic and fringe-littoral shark, occurring from the surface to at least 152 m. depth. Although an offshore species it may venture inshore, especially at night, and often in areas with a narrow continental shelf or off oceanic islands.In temperate waters blue sharks occasionally venture to the edges of kelp forests or sufficiently far inshore to be caught in pound nets. The blue shark is often found in large aggregations, not tightly organized schools, and often close to or at the surface in temperate waters.It prefers relatively cool water at 7 to 16°C but can tolerate water at 21°C or even more; it ranges far into the tropics but shows tropical submergence and occurs at greater depths there. In the tropical Indian Ocean the greatest abundance of blue sharks occurs at depths of 80 to 220 m, with temperatures about 12 to 25°C. The blue shark is often seen cruising slowly at the surface, with its large pectoral fins outspread, and its first dorsal fin and terminal caudal lobe out of the water. [more...] Viviparous, with a yolk-sac placenta; number of young 4-135 per litter. The number of young varies considerably among females, more so than any other livebearing shark, and may be partially dependent on size of the female. In the Indian Ocean sex ratios of fetuses were in aggregate 1:1, though individual females often have slightly more of one sex than another. The gestation period is 9 to 12 months, and possible maximum age at least 20 years. Off the Western North Atlantic most female blue sharks are immature at 0 to 4 years old, adolescent at 4 to 5 years, and adult from 5 to 6 years and beyond. Males mature at about 4 to 5 years old. [more...] The blue shark feeds heavily on relatively small prey, especially bony fishes and squid, though other invertebrates, small sharks, and mammalian carrion is readily taken and seabirds occasionally are caught at the surface of the water. Much of the prey of the blue shark is pelagic, though bottom fishes and invertebrates figure in its diet also. [more...] Squid are a very important prey of these sharks; [more...]

Maximum size 383 cm on reasonably good evidence, though unconfirmed reports of larger individuals up to 4.8 to 6.5 m are mentioned in the literature; males maturing between 182 and 281 cm, and reaching at least 311 cm, females adolescent at 173 to 221 cm, adult at 221 to at least 323 cm; size at birth about 35 to 44 cm. A length/weight equation for the blue shark (Strasberg, 1958) is: Log Wt(lbs) = -5.396 + 3.134 log TL (cm).

fieldmarks: Dorsal coloration dark blue, bright blue on sides and abruptly white on the undersides, usually slender body, long snout, large eyes, gill raker papillae, long, narrow, pointed pectoral fins, short labial furrows, first dorsal fin on back but closer to the pectoral bases than the pelvics, second dorsal less than a third size of first but about opposite it, a weak keel on the caudal peduncle, and a narrow-lobed caudal fin with a long ventral lobe. Body rather slender. Head narrow, only moderately depressed, not trowel-shaped; snout narrowly parabolic in dorsoventral view, very long, with preoral length greater than internarial space and mouth width; eyes large, without posterior notches; spiracles absent; unique papillose gill rakers present on internal gill openings; nostrils small, internarial space about 2.5 to 3 times the nostril width; anterior nasal flaps very short and broadly triangular, not tubular; labial furrows very short with uppers shorter than lowers and with their ends falling far behind eyes; teeth well differentiated in upper and lower jaws; upper and anteroposteriors with broad, triangular, curved erect to oblique, serrated cusps but with no blades or cusplets (except in very young specimens); lowers with slender cusps, no blades or cusplets, and variable serrations; cusps of lower teeth not prominently protruding when mouth is closed; 24 to 31/25 to 34 rows of teeth. Interdorsal ridge absent; low dermal keels present on caudal peduncle; upper precaudal pit transverse and crescentic. First dorsal origin well behind pectoral rear tips, its midbase much closer to pelvic than to pectoral bases, and free rear tip slightly anterior to pelvic origins; second dorsal fin much smaller than first, its height 1/2 of first dorsal height or less; its origin slightly posterior to anal insertion; pectoral fins very narrow and somewhat falcate, pectoral length from origin to free rear tip 1/2 or less of pectoral anterior margin; pectoral origins varying from under interspace between third and fourth gill slits to under fourth gill slits; anal slightly larger than second dorsal, with short preanal ridges and a deeply notched posterior margin. Colour intense deep blue above, white below, without a colour pattern. Large sharks, adults possibly reaching 4 m or more.

Oceanodromous. Migrating within oceans typically between spawning and different feeding areas, as tunas do. Migrations should be cyclical and predictable and cover more than 100 km.

Found worldwide in tropical and temperate seas; a pelagic species, sometimes advancing into coastal waters (Ref. 9137). Occurs on the continental shelf (Ref. 75154). Prefer temperatures of 7-16°C; usually found in deeper waters in the tropics (Ref. 5951). A carnivore (Ref. 9137). Parasites of the species include: Hepatoxylon squali pleurocercoid, Phyllobothrium dagnallium, Phyllobothrium sp. and Platybothrium parvum (Ref. 5951).

Dorsal spines (total): 0; Dorsal soft rays (total): 0; Analspines: 0; Analsoft rays: 0

Distinct pairing with embrace (Ref. 205). Viviparous (Ref. 26281), placental (Ref. 50449); 4-63 young in a litter (Ref. 9997); 4-135 (usually 15-30) pups (Ref.58048), about 35-44 cm at birth. Gestation period ranges from 9 to 12 months (Ref. 244).Sexual dimorphism is evident in skin thickness of maturing and adult females (Ref. 49562). Females have thicker skin layer than males of the same size (Ref. 49562).

A slim, graceful blue shark with a long, conical snout, large eyes, and curved triangular upper teeth with saw edges; pectorals long and narrow; no interdorsal ridge (Ref. 5578). Dark blue dorsally, bright blue on the sides, white ventrally (Ref. 5578). Tips of pectoral fins and anal fin dusky (Ref. 9997). The first case of diprosopus tetrophthalmus (cranofacial duplication) in a foetus of this species was reported from South Atlantic (Ref. 119190).

Oceanic, but may be found close inshore where the continental shelf is narrow (Ref. 6871, 58302). Usually found to at least 150 m (Ref. 26938). Maximum size from Ref. 128029. Reported from estuaries (Ref. 26340). Epipelagic, occasionally occurs in littoral areas (Ref. 58302). Feeds on fishes (herring, silver hake, white hake, red hake, cod, haddock, pollock, mackerel, butterfish, sea raven and flounders (Ref. 5951)), small sharks, squids, pelagic red crabs, cetacean carrion, occasional sea birds and garbage (Ref. 5578). Viviparous (Ref. 50449). Sexual dimorphism occurs in skin thickness of maturing and adult females (Ref. 49562). May travel considerable distances (one specimen tagged in New Zealand was recaptured 1,200 km off the coast of Chile) (Ref. 26346). Potentially dangerous to humans (Ref. 6871, 13513). Marketed fresh, dried or salted, and frozen; meat utilized for consumption, hides for leather and fins for soup (Ref. 9987). Sexually mature at 250 cm long and 4-5 years old. The female gives birth up to 80 young measuring 40 cm long, gestation lasts almost a year (Ref. 35388). Produces from 4 to 135 young a litter (Ref. 26938).

fisheries: minor commercial; gamefish: yes; price category: medium; price reliability: reliable: based on ex-vessel price for this species

分布於全球各溫、熱帶水域。臺灣東北部及東部海域有分布。

主要以底拖網、圍網、誘籠、流刺網及延繩釣捕獲，具經濟價值。肉質尚可，可加工成各種肉製品；鰭可做上品魚翅；皮厚可加工成皮革；肝可加工製成維他命及油；剩餘物製成魚粉。

體呈紡錘型，軀幹頗修長。頭窄而縱扁。尾基上下方各具一凹窪。吻長而呈拋物線狀。眼大，圓形，眼眶後緣不具缺刻，瞬膜發達。前鼻瓣短而呈寬三角形；無口鼻溝或觸鬚。唇溝短，通常僅侷限於口角部位。口裂寬大，深弧形，口閉時下頜齒不明顯露出；上頜齒寬扁三角形，外緣凹入，邊緣具明顯鋸齒，齒尖稍外斜，無小齒尖；下頜齒較窄長而直立，邊緣具鋸齒。噴水孔缺如。背鰭2個，背鰭間無隆脊，第一背鰭中大，起點遠在胸鰭基底之後，後緣凹入，上角鈍尖，下角尖突；第二背鰭小，起點與臀鰭起點相對，後緣入凹，後角尖突；胸鰭狹長，後緣凹入，外角尖突，內角圓突，鰭端伸達第一背鰭基底後部；尾鰭窄長，尾椎軸上揚，下葉前部顯著三角形突出，中部低平延長，與後部間有一深缺刻，後部小三角形突出，尾端尖突。體背側深藍色；腹側白色；體無任何色斑。胸及臀鰭之鰭尖暗色。

棲息於大洋上層大型鯊魚，偶可見於沿海水域，曾有報導出現於河口區。一般皆在水表面活動，胸鰭開展，背鰭及尾鰭上葉會露出水面，緩慢游動。性兇猛，活動力強，對人們具有主動攻擊的危險性。主要以硬骨魚類、甲殼類、頭足類、海洋哺乳類、海龜、海鳥、大洋性蟹類等為食，甚至垃圾等。胎生，一胎可產下4-135尾幼鯊，剛出生之幼鯊體長可達35-44公分。

The blue shark (Prionace glauca), also known as the great blue shark, is a species of requiem shark, in the family Carcharhinidae, which inhabits deep waters in the world's temperate and tropical oceans. Averaging around 3.1 m (10 ft) and preferring cooler waters, the blue shark migrates long distances, such as from New England to South America. It is listed as Near Threatened by the IUCN.

Although generally lethargic, they can move very quickly. Blue sharks are viviparous and are noted for large litters of 25 to over 100 pups. They feed primarily on small fish and squid, although they can take larger prey. Maximum lifespan is still unknown, but it is believed that they can live up to 20 years.

Lives in the open sea, but may also be found along coastal areas. Prefers cool waters from 7-16° C but tolerates 21° C and more. In tropical offshore areas it occurs at depths of 80-220 m; in warm-temperate areas they occur close to shore and near the surface (Ref. 5485). A scavenger/ predator that feeds mainly on squid, but also on bony fishes, small sharks, pelagic crustaceans, algae, and crustaceans (Ref. 5213). Length of 650 cm is unconfirmed. Marketed fresh, dried/salted and frozen; meat utilized for consumption, hides for leather and fins for soup (Ref. 9987).

Primarily squids and fishes, including herring, silver hake, white hake, red hake, cod, haddock, pollock, mackerel, butterfish, sea raven and flounders

Newfoundland to Argentina

Prefers waters if 7-16 C, often near surface.

nektonic

Known from seamounts and knolls