This week’s featured species is known for its dynamic and acrobatic hunting strategies that often results in the shark leaping and twisting through the air. The Spinner Shark (Carcharhinus brevipinna) is a moderately sized shark in the family Carcharhinidae (Ebert, Fowler, & Dando, 2015). They have slender bodies with long, narrow snouts and small, circular eyes. Their pectoral fins are relatively small and both dorsal fins are relatively short as well for their size (Ebert, Fowler, & Dando, 2015). Their fins (dorsal, pectoral, pelvic, anal, and caudal) are edged with black tips.
The spinner shark primarily feeds on schooling bony fish like sardines, herring, mullet, and bluefish (Burgess, 2009). They do occasionally feed on cephalopods like squid and cuttlefish, as well as other smaller elasmobranchs like stingrays. Their teeth are specifically designed for handling slippery prey items, like bony fishes. In the upper jaw, the teeth are symmetrically erect towards the center margin of the jaw. In the lower jaw, the cusps are slightly more narrow than the upper jaw, with a more broad base (Bester, 2018).
Spinner sharks are known for their incredible acrobatics! These sharks really put on a show when they are hunting! Spinner sharks will swim rapidly through a school of fish towards the surface with their mouths wide open. As they shoot towards the surface, they twist and turn their bodies along an axis, snapping their jaws at every fish along the way. Their high speed and upward momentum carries them up and out of the water, typically twisting several times before landing on their backs with a splash (Burgess, 2009)! The video below is the perfect example of these incredible aerial feats!
FrontYardVideo (Videographer). (2016 January). Spinner Sharks Jumping FYV Thanks john Oliver! [Video Clip]. Retrieved from https://www.youtube.com/
Like many other large elasmobranch species, the spinner shark is facing several threats directly related to humans. The spinner shark utilizes inshore estuaries, bays, and beaches as their pupping grounds and nurseries. These areas are highly vulnerable to habitat degradation and destruction by human development and alteration (Burgess, 2009). The loss of valuable nursery habitat could have vast implications for juvenile survival and the future survival of the species. The spinner shark is also directly target by commercial and recreational fisheries. Commercially, the spinner shark is prized for the fins in the East Asian markets. In some regional markets, the hides are also prepared for leather and the livers are utilized for the oils (Burgess, 2009). They are also prized in recreational fishing.
The spinner shark is easily misidentified with another Carcharhinidae species, the blacktip shark (Carcharhinus limbatus) (Tricas, et al, 1997). These two species share the same home range, as well as the same inshore habitat preference. They also have strikingly similar body structures and black tip markings. However, the blacktip shark does not have a black tip on the anal fin, while the spinner shark has black tips on all fins. The spinner shark also has the first dorsal fin slightly further on the back than the blacktip shark. However, the similarities are so similar that it is likely landings data for the spinner shark are reported as a blacktip shark (Burgess, 2009). Any products from these misidentified spinner sharks would then be sold under “blacktip shark,” making it difficult to determine the true number of landings and products derived from spinner sharks every year (Burgess, 2009). The spinner shark is currently listed as a Near Threatened species by the International Union for Conservation of Nature (IUCN). Continued careful monitoring of the species is required.
Authority: Müller & Henle,1839
Family: Carcharhinidae; 59+ species
Length: Up to 9.1 feet (2.78 m)
Weight: Up to 110 lbs (49.8 kg)
Habitat: Coastal; close inshore along insular and continental shelves
Depth: Surface to 246 feet (75 m)
Reproduction: Placental Viviparous
Gestation: 11 – 15 months
Litter Range: 3 – 20 pups; average 7 – 11 pups
Home Range: Warm temperate and tropical waters of the Atlantic, Mediterranean, and Indo-West Pacific Oceans
Diet: Bony fishes, cephalopods, some small elasmobranchs
IUCN Status: Near Threatened
(Castro, 1993; Burgess, 2009; Ebert, Fowler, & Dando, 2015)
Thanks so much for checking out the Spinner Shark! If you missed last week’s featured species, please be sure to check out the prickly Bramble Shark! If there is a species of elasmobranch you’d love to know more about, leave me a comment or send me a message! I would love to do a feature on your favorite species. So connect with me on Instagram and Facebook for even more elasmo fun!
The new Ocean For Sharks Shop is open! There’s handmade ocean inspired plush animals, canvas paintings, and of course my children’s book, Winifred the Wondrous Whale Shark, available in print and PDF. Be sure to stop by. Remember proceeds benefit shark research and conservation with a donation to Project AWARE!
Conservation legislation needs public support in order to become law and help protect the environment and wildlife. Tell your representatives that you care about environmental and wildlife conservation. It only takes a moment to make a change that will last a lifetime. Until next time finactics!
Featured Image Source
Paulson, M. (2016, January 25). Spinner Shark Jump 1, Tampa Electric Manatee Viewing Area, Tampa, Florida [Digital Image]. Retrieved from https://www.flickr.com/photos/matthewpaulson/24379722934
Bester, C. (2018, October 18). Carcharhinus brevipinna (L. French & G. Bester, Eds.). Retrieved from https://www.floridamuseum.ufl.edu/discover-fish/species-profiles/carcharhinus-brevipinna/
Branstetter, S. (1987). Age and growth estimates for blacktip, Carcharhinus limbatus, and spinner, C. brevipinna, sharks from the northwestern Gulf of Mexico. Copeia, 964-974.
Burgess, G.H. (2009). Carcharhinus brevipinna. The IUCN Red List of Threatened Species. Retrieved from https://www.iucnredlist.org/species/39368/10182758
Castro, J. I. (1993). The shark nursery of Bulls Bay, South Carolina, with a review of the shark nurseries of the southeastern coast of the United States. Environmental biology of fishes, 38(1-3), 37-48.
Ebert, D. A., Fowler, S. L., & Dando, M. (2015). Sharks of the world: a fully illustrated guide. Wild Nature Press.
Tricas, T. C., Deacon, K., Last, P., McCosker, J. E., Walker, T. I., & Taylor, L. (1997). The Nature Company Guides: Sharks and Rays. (L. Taylor, Ed.). Hong Kong: The Nature Company, Time Life Books.