Porbeagle shark - Lamna nasus
WHAT TO LOOK FOR
This is a heavy bodied shark with a short, conical snout, and long gill slits. It has a strong keel on its caudal peduncle with short, secondary keels on the base, and a crescent tail. Northern and Southern shown in illustration.
Dark grey or blackish on top, with the underside being white with dusky blotches. It has a very distinctive white tip on its first dorsal fin.
The shark is 1.9 to 2.6 ft [60 to 80 cm] long at birth. Porbeagle sharks are extremely slow to reach sexual maturity (18 to 26 years). Males mature at 4.9 to 6.7 ft [1.5 to 2 m] in length, and females mature at 6.7 to 8.2 ft [2 -2.5 m] (but can be smaller in the south Pacific). Its maximum length can be over 9.8 ft [300 cm].
Inshore to continental offshore fishing banks. They are occasionally in the open ocean, from less than 3.3 to 2296.6 ft [1 to 700 m] deep.
The sharks are found in the north Atlantic, and cool water areas 33.8 to 64.4ºF [1 to18ºC] in the southern hemisphere. They are not found in equatorial seas.
Prey – Small fishes, dogfish, tope and squid.
Reproduction – Porbeagle sharks have long gestation periods, and generally bear litters of only 4 pups.
This is a migratory species that moves inshore and to the surface in the summer months. It spends the winter offshore in deeper water. Populations are segregated by age (size) and sex. The shark is inquisitive, and may approach boats and divers.
The Porbeagle shark is Critically Endangered in the Northeast Atlantic and Mediterranean where fisheries are unmanaged. The Mediterranean population has virtually disappeared. It is Endangered n the Northwest Atlantic — female spawning stock has decreased to 12% and 16% of previous levels. In the Southern Ocean it is classed as Near Threatened –depletion of spawning stock indicates biomass is 18% of previous levels. The North Atlantic population has been seriously depleted (~90%) by commercial fisheries for the shark’s high value meat.
After multiple attempts and efforts to secure protections, the Porbeagle shark was placed on CITES Appendix II in 2016.