Blue shark

Blue Shark Temporal range: Pliocene–Recent PreЄ Є O S D C P T J K Pg N
Conservation status
Near Threatened (IUCN 3.1)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Chondrichthyes
Subclass:	Elasmobranchii
Order:	Carcharhiniformes
Family:	Carcharhinidae
Genus:	Prionace Cantor, 1849
Species:	P. Glauca
Binomial name
Prionace glauca (Linnaeus, 1758)
Range of the blue shark

The Blue shark (Prionace Glauca) is a species of requiem shark. It is found in deep waters of temperate and tropical oceans. Blue sharks migrate long distances, for example they sometimes migrate from New England to South America. Blue sharks prefer cool waters.

Description

Blue sharks grow up to the length of around 3.8 meters (12.5 ft) and weigh around 204 kg (450 Ib). The heaviest ever found weighed 391 kg (860 Ib). Blue sharks have long pectoral fins and are light-bodied. The top of the Blue shark is dark blue and the belly is white.

Wolves of the Sea

Often, the blue shark travels alone, but sometimes they come together in groups if there is food around. This is why Blue sharks are known as "wolves of the sea", because just like wolves they come together in groups to hunt for food. But groups of Blue sharks are known as "schools", and groups of wolves are known as "packs". Blue sharks usually form schools with other Blue sharks that are the same size. But the groups are always all-male or all-female. Nobody knows for sure why they do this.

The back of a Blue Shark

Feeding

Blue sharks eat mainly squid, but sometimes they eat other mollusks like octopus and cuttlefish. They also eat some crustaceans like crabs and lobsters, a large number of bony fish, small sharks, and sometimes sea birds.

Predators

Blue sharks have no real predator, but sometimes young Blue sharks may be killed by humans or eaten by Great white sharks or Tiger sharks. Blue sharks sometimes may be killed by parasites, like tetraphyllidean tapeworms. Also, Blue sharks sometimes may be infected from eating Opah or longnose lancetfish.

Where they live

The Blue shark is found worldwide in deep waters of temperate and tropical waters, they are found from the surface of the water to as deep as 350 meters. The Blue shark is found as far north as Norway, to as far south as Chile. Blue sharks are found off the coasts of every continent except Antarctica. They prefer to live in waters with the temperature of 7-16 °C (45-61 °F), but sometimes may be found in waters with the temperature of 21 °C (70 °F).

Relationship with humans

The Blue shark is known as a game fish. This means humans fish for this shark for fun or for games or sports. Every year 10 to 20 million Blue sharks are killed because of fishing. The flesh of this shark is eatable, but not many people eat it. The skin of the Blue shark is usually used for making leather, the fins are used to make shark-fin soup, and the liver is used to make oil.

Sources

• Scholz, Tomáš; Euzet, Louis; Moravec, František (1998). "Taxonomic status of Pelichnibothrium speciosum Monticelli, 1889 (Cestoda: Tetraphyllidea), a mysterious parasite of Alepisaurus ferox Lowe (Teleostei: Alepisauridae) and Prionace glauca (L.) (Euselachii: Carcharinidae)". Systematic Parasitology 41 (1): 1–8. doi:10.1023/A:1006091102174.

Other websites

• Prionace glauca (TSN 160424). Integrated Taxonomic Information System.
• Blue shark, Prionace glauca MarineBio"
• Blue shark, Prionace glauca at the Encyclopedia of Life
• ARKive - Images and movies of the blue shark (Prionace glauca)
• Canadian Shark research laboratory
• BBCNews - 'Jaws' comes to a US beach 3 August 2010.
• BBCNews - Footage of shark which closed New Quay (Wales) beach 8 August 2012.