A goblin shark is a type of deep water shark that has a retractable jaw. Rarely seen, goblin sharks are not studied in great numbers, but are thought to be relatively common. The scientific name for the goblin shark is Mitsukurina owstoni.
The goblin shark has a long, flat, pointed snout, small eyes, and a flabby pink-gray body. Its tail is asymmetrical, much longer on top than it is on the bottom. The largest of this species ever record was 12.6 feet (3.8 m), but they average around 5 feet (1.6 m). From the few samples studied, females seem to be larger than males.
The most remarkable feature of this shark is its jaws. Connected to the mandibular joints by ligaments which are either relaxed or contracted, the jaws are capable of shooting forward to capture prey. When the ligament are contracted the jaws sits flush against the body, their half-moon shape appearing very similar to other, more familiar, shark species. When the goblin shark senses food, the ligaments relax, and the jaws rapidly flash out, mouth wide, to capture the prey in its loosely spaced, needle-like teeth.
The goblin shark senses potential food by using organs in its snout called ampullae, which they use to detect their prey's bioelectric signatures. It likely remains mostly motionless when hunting, preferring the prey to come to it. Goblin sharks eat shrimp, squid, and soft bodied fish, as well as crabs. Not much about their diets is known since there is little scientific information about their stomach contents.
Most frequently found in Japan, goblin sharks live on outer continental shelves worldwide. Having been found at depths of 130-3,940 feet (40-1,200 m), they are thought to live near the bottom or at mid-level of their ocean habitats. They are assumed to be slow swimmers because their asymmetrical tails and muscle tone are not suited for speed.
Since a pregnant female has never been caught, means of reproduction is not known. Scientists speculate, however, that these sharks are ovoviviparous, meaning they give birth to live offspring, but the offspring are incubated inside fertilized eggs which hatch inside the body before birth. Scientists have come to this conclusion because most other sharks of the Lamniformes order — to which goblin sharks belong — are ovoviviparous.
The goblin shark is rarely caught intentionally, and is usually a by-catch of commercial fisherman. It is thought to be of minimal danger to humans, but has had relatively little contact with humans. There are about 45 specimens of goblin shark kept for study by scientists.