The bluntnose sixgill shark, as the name suggests, has six gill slits instead of the usual five.
This indicates that it is one of the more primitive sharks and is closely related to the extinct shark species of the past.
They are slow, but strong swimmers, and are capable of the occasional burst of speed when it's necessary to catch prey.
A bit like me and public transport then.
These sharks are large, powerful, and heavy-bodied. Ooh, like me again. No wonder I like these guys so much.
At birth the pups measure between 65 and 75cm. Mature males average between 310 and 330cm and the female is larger at between 350 and 420cm. The maximum length is around 550cm.
They range in colour from a light grey or brown to almost black on top and may have darker patches of colour on their sides. The underside is paler.
The eyes of this shark are a fluorescent bluey green colour.
The fins are soft and supple. The single, spineless dorsal fin is set well back on the body. The paired Pectoral fins are angular and fairly large in comparison to the pelvic fins. A single anal fin is present and the caudal fin has a well developed upper lobe with a marked sub terminal notch.
Their lower teeth are large and comb-shaped and set in 5 to 7 rows. The upper teeth are smaller and cusped.
They like bony fish, squid, and small sharks and rays. Larger sharks will also prey on cetaceans and pinnipeds.
This shark is ovoviviparous. The gestation period is unclear but may be as long as two years. Wow, let's hope they don't suffer from morning sickness.
Litter sizes range from as few as 20 to as many as 100 pups at a time.
They're found worldwide and may be one of the most widely distributed of all sharks. As they are often sensitive to light, they prefer to stay at depths of up to 1800m by day and are found in water as shallow as 30m at night.