The Japanese fishermen who caught the first specimen of Mitsukurina in the "Black Current" off Yokohama called it tenguzame, which means "goblin shark." This has become its common name, although very few people besides ichthyologists and shark-book authors ever get a chance to use it. The shark is extremely rare, found only in deep water off Japan, South Africa, perhaps off Portugal, and, in one strange instance, in the Indian Ocean, cable malfunction necessitated the raising of the cable, and an awl-like shark's tooth was found embedded in the wire covering. The cable had been at 750 fathoms, and the tooth belonged to a goblin shark.
The shark is thought to have been feeding on some sort of animal life growing on the cable at that depth, but very little else is known of its feeding habits. Its awl-like teeth and protrusible jaws seem to indicate that it is a fish eater, but this is only a supposition. (It probably needs protrusible jaws to feed at all, given the nature of its forehead appendage. This seems a self-handicapping situation, so perhaps the protrusion serves some other, less problematical function.) The first known tenguzame was a 3.5-foot male, but subsequent specimens have been as long as 14 feet.
This seems to me the strangest of all the sharks. It looks like some kind of prehistoric survivor, an experiment in shark design that doesn't seem to work. And yet, by definition, it does work. Triceratops, the dinosaur with three horns, is long gone, as are Pteranodon and hundreds of other "impossible" animals. There is little that can be said about this mysterious shark, because so little is known about it. And yet, we have the most curious, incontrovertible fact of all: Mitsukurina lives.
According to National Geographic Kids: A fourth of the goblin shark's weight can be its liver. Scientists don't yet understand why its liver is so big. These sharks have been found as deep as 4,000 feet. This 10-foot-long shark preys on small octopuses and fish. It has rarely even been seen by people. The shark's "nose" is dotted with sensory cells. Scientists think the snout's main purpose is to help the shark find food in deep, dark waters.