March is a month for east coast sharks. Today we feature the Spinner shark, Carcharhinus brevipinna, which gets its common name from the way it moves while feeding. This species of shark is fast and will literally spin through the water and through various pelagic schools of fish, biting in all directions. They have even been spotted spinning out of the water to catch their prey.
This shark swims in schools that migrate off the Florida and Louisiana coasts, as well as in the Gulf of Mexico. They migrate closer to shore to feed and reproduce during the spring and summer. Spinner sharks are viviparous (remember the yolk sac placenta from our last post on shark gestation and birth? Of course you do smarty-pants!) and like to birth their pups in higher salinity estuaries near shore. This species of shark is able to have 3-15 pups, which grow approximately 6 inches within the first 6 months.
This shark species has been designated “Near Threatened” by The World Conservation Union. Spinner sharks are often misidentified as blacktip sharks in the fishing industry based. For one thing, Spinner sharks look similar in shape and size. In addition, blacktips are highly sought after in the shark fishing industry, which means that it is more profitable for fisheries to report high yields of blacktips. There are currently no conservation efforts for Spinner sharks.
Join us next week to look at another sharky resident of the North American Eastern coast.
Edited by KC O’Shea
Photography: Mark Mohlmann; http://australianmuseum.net.au/image/spinner-shark-carcharhinus-brevipinna and stsimonsfishing.com