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The spinner shark ( Carcharhinus brevipinna) is a type of requiem shark, in the 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 , 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 .
Spinner sharks are swift and gregarious that feed on a wide variety of small and . When feeding on schools of forage fish, they 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 three to 20 young every other year. The young 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 has assessed this species as Vulnerable worldwide.
Based on similarities in morphology, tooth shape, and behavior, the closest relatives of the spinner shark were originally believed to be the blacktip shark and the graceful shark ( C. amblyrhynchoides).Garrick, J.A.F. (1982). "Sharks of the genus Carcharhinus". NOAA Technical Report, NMFS CIRC-445. However, this interpretation was not supported by Gavin Naylor's 1992 allozyme analysis, which suggested that these similarities are the product of convergent evolution and that the closest relative of the spinner shark is the copper shark ( C. brachyurus). In a 2007 ribosomal DNA study, the spinner shark was found to be the most genetically divergent of all the requiem shark species examined save for the tiger shark ( Galeocerdo cuvier), being less related to other Carcharhinus species than the lemon shark ( Negaprion brevirostris).
The earliest fossil record of the spinner shark is from the Late Miocene of Panama. They are also known from the Late Miocene of Odisha, India and potentially the Middle Miocene to Early Pliocene of Florida, US.
The spinner shark has been reported from the ocean surface to a depth of , though it prefers water less than deep, and occupies all levels of the water column. 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 fish migration; in spring and summer, they are found in warm inshore waters, and in winter, they move south into deeper water.
The first dorsal fin is relatively small and usually originates behind the free rear tip of the . No ridge exists between the first and second dorsal fins. The pectoral fins are moderately short, narrow, and falcate (sickle-shaped). The body is densely covered with diamond-shaped with seven (rarely five) shallow horizontal ridges. 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.
The length at birth is in the northwestern Atlantic, off Tunisia, and off South Africa. Spinner sharks are relatively fast-growing sharks: per year for newborns, per year for one-year-olds, per year for adolescents, and per year for adults. In the northwestern Atlantic, males mature at long and females at long, corresponding to ages of 4–5 years and 7–8 years, respectively. Off South Africa, males mature at and females at . Spinner sharks generally do not reproduce until they are 12–14 years old. The maximum lifespan has been estimated at 15–20 years or more.Fowler, S.L. (2025). 9782831707006, International Union for Conservation of Nature and Natural Resources. ISBN 9782831707006
The meat of the spinner shark is of high quality and sold fresh or dried and salted. In addition, the fins are used for shark fin soup in East Asia, the liver oil is processed for , and the skin is made into leather products. Spinner sharks are an important catch of the US commercial shark fisheries operating in the northwestern Atlantic and the Gulf of Mexico. The meat is marketed under the name "blacktip shark" in the United States, due to that species being considered superior in quality by consumers. It is likely also caught by other fisheries across its range, going unreported owing to confusion with the blacktip shark. The spinner shark is also highly regarded by recreational fishers, being described as a "spectacular fighter" that often leaps out of the water.
The IUCN has assessed the spinner shark as Vulnerable worldwide; its frequent use of coastal habitats renders it vulnerable to human exploitation and habitat degradation. The Northwest Atlantic fishery for this species is managed under the US National Marine Fisheries Service 1999 Fishery Management Plan for Atlantic Tunas, Swordfish, and Sharks. For the purposes of commercial quotas and recreational bag limits, the spinner shark is categorized as a "large coastal shark".
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