Hexanchus griseus, commonly known as the bluntnose sixgill shark, is a species of deep sea shark belonging to the hexanchidae family. It is one of the few extant species within the Hexanchus genus and is characterized by its unique anatomical features.
The bluntnose sixgill shark can be identified by its large, cylindrical body that can reach lengths of up to 5.5 meters (18 feet). It has a broad, blunt snout and possesses six gill slits on each side of its head, which are more than most shark species that usually have five. This feature gives the shark its common name. Its dorsal fin is positioned further back on its body compared to other sharks, and it lacks an anal fin.
This species typically inhabits deep ocean waters, dwelling as deep as 2,500 meters (8,200 feet). It has a wide distribution, found in various oceans around the world including the Atlantic, Pacific, and Indian Oceans.
Being a solitary and slow-moving shark, the bluntnose sixgill primarily feeds on carrion and scavenges on dead or dying animals that sink to the ocean floor. However, it is also known to be an opportunistic predator, preying on a variety of marine organisms such as fish, seals, and other sharks.
Due to its deep-sea habitat, limited research has been conducted on the bluntnose sixgill shark. Thus, the knowledge about its behavior, reproductive strategies, and population numbers remains incomplete. However, it is considered a vulnerable species due to its slow growth, late maturity, and high longevity.
