[4] Pups are 41 to 50 cm (16 to 20 inches) long at birth,[3] with females giving birth to 4-135 pups at a time, but the number of pups depend on the size of the female, with larger females giving birth to more pups. The second dorsal fin measures almost half the size of the first and its pectoral fins are unusually long compared to other sharks. [19] Most of these were in captivity for about three months or less,[19] and some of them were released back to the wild afterwards. Migrations often follow major trans-oceanic currents. The term “glauca” comes from the Latin meaning “blue-gray” or “green.” It is the most distributed shark in the world. They have been known to feed on almost anything that they can find, including prey items which they can find in large numbers such as shrimp. The fins are used to make shark-fin soup, while the liver yields oil. Rigby, C.L., Barreto, R., Carlson, J., Fernando, D., Fordham, S., Francis, M.P., Herman, K., Jabado, R.W., Liu, K.M., Marshall, A., Pacoureau, N., Romanov, E., Sherley, R.B. The gestation period is between nine and 12 months. Averaging around 3.1 m (10 ft) and preferring cooler waters,[3] the blue shark migrates long distances, such as from New England to South America. The courtship ritual includes the male biting the female, so one way to sex a blue shark is to look for the bite scars always found on mature females. The pups are an important food source for other predators, but sharks that survive to maturity may live 20 years.
Blue sharks may eat tuna, which have been observed taking advantage of the herding behaviour to opportunistically feed on escaping prey. Blue sharks are viviparous and are noted for large litters of 25 to over 100 pups. This shark has a dark blue back, bright blue flanks and sharp demarcation to a white underside.
Due to their territorial instincts and their aggressive behaviours, divers have to be very careful around them. [18][19] For example, several blue sharks kept at Sea World San Diego initially did fairly well, but were eaten when bull sharks were added to their exhibit. In the western Pacific they are found from Japan to New Zealand.
As a consequence: the blue shark is “Near Threatened” according to the Red List of the International Union for the Conservation of Nature. Killer whales have been reported to hunt blue sharks. & Winker, H. (2019). The dorsal surface is a dark blue colour, and the belly is white. The shark's dermal denticles (scales) are small and overlap, making the animal's skin smooth to the touch. Mature females are larger than males. Blue sharks rarely bite humans and almost never cause death. Male sharks mature by four or five years of age, while females mature at five to six years of age. Blue sharks inhabit cool ocean waters around the globe, as far south as Chile and as far north as Norway.
The blue shark sometimes circles swimmers or divers for up to fifteen minutes or more. In temperate regions, they may be found offshore, but in tropical waters, they have to swim deeper to seek a comfortable temperature. Females average from 2.2 to 3.3 m (7.2 to 10.8 ft) in length, weighing 93 to 182 kg (205 to 401 lb). [11] Records from the Atlantic show a regular clockwise migration within the prevailing currents.[3]. [5] The blue shark is fairly elongated and slender in build and typically weighs from 27 to 55 kg (60 to 121 lb) in males and from 93 to 182 kg (205 to 401 lb) in large females. Whale and porpoise blubber and meat have been retrieved from the stomachs of captured specimens and they are known to take cod from trawl nets. Blue Shark Facts: Size, Habitat, Reproduction. Blue sharks are found off the coasts of every continent, except Antarctica. The blue shark (Prionace glauca) is a species of requiem shark. They have been known to eat other sharks, cetaceans (whales and porpoises), and seabirds. Blue sharks may eat tuna, which have been observed taking advantage of the herding behaviour to opportunistically feed on escaping prey. Like other species in the requiem family, the blue shark is migratory and ectothermic, and it gives birth to live young.