Feb Elasmobranch of the Month: Tope Shark
Tope (School shark )
Image credit: Andy Murch
Key Features The tope shark is a slender bodied species with a notably elongated snout. Two dorsal fins are present, the first notably larger than the second, with the second dorsal being positioned directly above the anal fin (Shark Trust, 2010). Colourations can vary from sandy brown-grey (SSACN, 2015) on the dorsal side and blends to white on the ventral. Mature females can reach a maximum size of 195 cm (Shark Trust, 2010). Habitat Tope are a wide-ranging species in temperate waters (Walker et al., 2006), found in the east and southwest Atlantic Ocean, the western Indian Ocean and most of the Pacific Ocean (Walker et al., 2006; Shark Trust 2010). Tope are often found close to the seabed at a range of depths from the surface to 750 meters (SSACN, 2015). A migratory species, tope have been known to travel large distances. Individuals initially caught in the UK have been recaptured as far as the Canary Islands- that’s 2700 miles (SSACN, pers comms)! Food Source Although the tope often remains close to the sea floor, their diet can vary between bottom-dwelling and mid-water species. Prey items range from bony fish (such as mackerel, herring and cod), to cephalopods and crustaceans. Status The tope is classified as “Vulnerable” on the IUCN Red List of Threatened Species. Threats This species is valued for a number of goods and therefore is subject to a variety of threats throughout its range. Highly desired for their liver-oils, fins and meat (Walker et al., 2006), fishing pressure is higher in parts of Europe (where their meat is used in local dishes) and South America. Not only this, but their fins are also exported to Asia for the shark fin soup trade. As with many shark species, tope are also caught as bycatch by longline fisheries targeting tuna. Tope are thought to segregate by size and sex (Walker et al., 2006), thus increasing their vulnerability to fishing pressure.
Image credit: Andy Murch
References Scottish Sea Angling Conservation Network. 2015. Fish Factoids. Available at: https://www.ssacn.org/wp-content/flipread/SSACN%20Factoids%202015/files/assets/basic-html/page-7.html. (Accessed 1st September 2017). Walker, TI, Cavanagh RD, Stevens JD, Carlisle AB, Chiaramonte GE, Domingo A, Ebert DA, Mancusi CM, Massa A, McCord M, Morey G, Paul LJ, Serena G and Vooren CM. 2006. Galeorhinus galeus. The IUCN Red List of Threatened Species 2006: e.T39352A10212764. http://dx.doi.org/10.2305/IUCN.UK.2006.RLTS.T39352A10212764.en. (Accessed 1st September 2017). Shark Trust. 2010. An Illustrated Compendium of Sharks, Skates, Rays and Chimaera. Chapter 1: The British Isles. Part 2: Sharks.