Blue Shark
Scientific Name Prionace glauca
Conservation Status Near Threatened
Family Chordata
Habitat Deep Seas
Food Squid, mollusks, crustaceans

The blue shark, Prionace glauca, is a carcharhinid shark which is found in the deep waters of the world's temperate and tropical oceans. They prefer cooler waters and are not found, for example, in the Yellow Sea or in the Red Sea. Blue sharks are known to migrate long distances, from New England to South America for example. Although generally lethargic, they are capable of moving very quickly if the need arises. Blue sharks are viviparous and are noted for their large litters of 25 to over 100 pups. They feed primarily on small fish and squid, although they are perfectly capable of taking larger prey should the opportunity present itself. They are often found in schools segregated by sex and size, and this behavior has led to their being nicknamed the "wolves of the sea".

The blue shark is an oceanic and epipelagic shark found worldwide in deep temperate and tropical waters from the surface to about 350 meters.

Squid are an important prey item for blue sharks, but their diet also comprises other invertebrates such as cuttlefish and pelagic octopuses, as well as lobster, shrimp, crab, a large number of bony fishes, small sharks, mammalian carrion and occasional sea birds. 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. Apparently, blue sharks do not, or only very rarely, eat tuna.

Blue sharks are the most heavily fished sharks in the world mainly as result of by-catch. It is estimated that 10 to 20 million individuals are killed each year as a result of fishing. The flesh is edible, but not widely sought after; it is utilized fresh, dried, smoked and salted and for fishmeal. The skin is used for leather, the fins for shark-fin soup and the liver for oil. Blue sharks are occasionally sought as game fish, and they are frequent accidental catches by commercial fisherman seeking swordfish or tuna.