Spinner Sharks

There's video online today about a spinner shark that jumped out of the ocean by some surfers. It's not on youtube, but there are plenty of videos of spinner sharks there.



Spinner sharks are not dangerous to man. Indeed, they are are a threatened species because they are used for shark fin soup. (But apparently unlike other sharks that are thrown back to die after being de-finned, people who catch spinner sharks also use their flesh to eat and their skin to create clothing.

The spinner shark (Carcharhinus brevipinna) is a species of requiem shark, family Carcharhinidae, named for the spinning leaps it makes as a part of its feeding strategy. This species occurs in tropical and warm temperate waters worldwide, except for in the eastern Pacific Ocean. It is found from coastal to offshore habitats to a depth of 100 m (330 ft), though it prefers shallow water. The spinner shark resembles a larger version of the blacktip shark (C. limbatus), with a slender body, long snout, and black-marked fins. This species can be distinguished from the blacktip shark by the first dorsal fin, which has a different shape and is placed further back, and by the black tip on the anal fin (in adults only). It attains a maximum length of 3 m (10 ft).

Spinner sharks are swift and gregarious predators that feed on a wide variety of small bony fishes and cephalopods. When feeding on schools of forage fish, they will speed vertically through the school while spinning on their axis, erupting from the water at the end. Like other members of its family, the spinner shark is viviparous, with females bearing litters of 3–20 young every other year. The newborns are born in shallow nursery areas near the coast, and are relatively fast-growing. This species is not usually dangerous to humans but may become belligerent when excited by food. Spinner sharks are valued by commercial fisheries across their range for their meat, fins, liver oil, and skin. They are also esteemed as strong fighters by recreational fishers. The International Union for Conservation of Nature (IUCN) has assessed this species as Near Threatened worldwide and Vulnerable off the southeastern United States.