Texas Gulf Coast Fishing

Spinner Shark

SPINNER SHARK Carcharhinus brevipinna

The Spinner Shark is a species of requiem shark, 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 330 ft., though it prefers shallow water. The spinner shark resembles a larger version of the Blacktip Shark, 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 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.

Distribution: In the western Atlantic Ocean, it occurs from North Carolina to the northern Gulf of Mexico, including the Bahamas and Cuba, and from southern Brazil to Argentina. In the eastern Atlantic, it occurs from off North Africa to Namibia. In the Indian Ocean, it is found from South Africa and Madagascar, to the Red Sea and the Gulf of Aden, to India and nearby islands, to Java and Sumatra. In the Pacific Ocean it occurs off Japan, Vietnam, Australia, and possibly the Philippines.
Habitat: This species may be found from coastal waters to well offshore, over continental and insular shelves. Juveniles have been known to enter bays but avoid brackish conditions. The northwest Atlantic subpopulation is known to be migratory; in spring and summer they are found in warm inshore waters, and in winter they move south into deeper water.
Description: The average spinner shark is 6.4 ft. long and weighs 123 lbs; this species attains a maximum known length and weight of 10 ft. and 198 lbs. Indo-Pacific sharks are generally larger than those from the northwest Atlantic. This species has a slim, streamlined body with a distinctive long, pointed snout. The eyes are small and circular. There are prominent forward-pointing furrows at the corners of the mouth. The first dorsal fin is relatively small and usually originates behind the free rear tip of the pectoral fins. There is no ridge between the first and second dorsal fins. The pectoral fins are moderately short, narrow, and falcate (sickle-shaped). The coloration is gray above, sometimes with a bronze sheen, and white below, with a faint white band on the sides. Young individuals have unmarked fins; the tips of the second dorsal fin, pectoral fins, anal fin, and lower caudal fin lobe (and sometimes the other fins as well) are black in larger individuals. The spinner shark differs from the blacktip shark in that its first dorsal fin is slightly more triangular in shape and is placed further back on the body. Adults can also be distinguished by the black tip on the anal fin.
Feeding Habits: This species employs an unusual tactic when feeding on schools of small fish: the shark charges vertically through the school, spinning on its axis with its mouth open and snapping all around it. The shark's momentum at the end of these spiraling runs often carries it into the air, giving it its common name. Spinner Sharks follow migrating schools of mackerel, tunas, and jacks. Like blacktip sharks, they congregate around shrimp trawlers to feed on the discarded bycatch, and may be incited into feeding frenzies.