Facts about Goblin shark

Mitsukurinidae appeared in the late-Mesozoic era, about 125 million years ago. The oldest Mitsukurina fossils are from the middle Eocene and are 49-37 million years old. So far, two fossil species have been discovered: Mitsukurina lineata and Mitsukurina maslinensis.

It was described by American ichthyologist David Starr Jordan, who recognized it not only as a new species but also as a new family and genus.

It can be found in the Indo-Pacific and Oceania, Japan, South Africa, Gulf of Mexico, Suriname, French Guiana, southern Brazil, France, Portugal, Madeira and east of Senegal.

They can be found in seamounts, upper continental slopes and submarine canyons. Younger specimens usually reside in less deep waters than their older counterparts.

They are equipped with five pairs of gill slits, gill openings are short and not extending onto dorsal surface of the head.

The largest specimen so far has been caught in the Gulf of Mexico. Female measured at least 5,4 m, but dimensions were assumed by investigating photographs only. The maximum weight recorded so far is 210 kg, of a specimen 3,8 m long. Males reach maturity at body length between 2,64 and 3,22 m.

Goblin sharks have long and flat snouts, small eyes that lack nictitating membrane (which is unusual for sharks), long and narrow teeth in front of a jaw and flat ones located behind that are used for crushing food.

It has been observed, that this receptor is able to detect pressure, touch, salinity, temperature, electric and magnetic fields. The latest research indicates that ampullae of Lorenzini aids the sharks with sensing geomagnetic information, giving the fish ability to determine its location and help with navigation.

When catching prey, goblin sharks can protrude their jaws almost to the end of the snout. Usually though, their jaw stays at a natural position aligned with the underside of the head.

They have short and rounded fins, anal and pectoral fins are larger than the dorsal fins. The caudal fin is heterocercal, with a significantly larger upper lobe and lacking a middle lobe. Heterocercal fin is an asymmetrical type, where the upper lobe is bigger than the lower one. Such a fin is characteristic for the phylogenetically oldest fish.

Unlike many other sharks, the goblin shark has a rather slack and slender body and weak, poorly calcified skeleton. As their anatomy is not suitable for long pursuits after prey, they attack from an ambush. As soon as the shark gets close enough to prey, it catches it by mowing its jaw forward.

According to the book The Sharks of North America. by Jose I. Castro they are almost certainly ovoviviparous. A small number of fetuses develop in the mother's body, where they feed on unfertilized eggs. At birth, baby goblin sharks are at least 82 cm long.

Research of those fish has to be made in ocean waters as no individual survived in captivity for more than a week.

Among creatures found in their stomach are cephalopods, crustaceans, grenadiers and dragonfish.

They sometimes appear in fishnets and in this case are usually dried, salted and delivered to the market in that form. Bycatch is very rare and it is most common in southern Japan, where about 30 individuals, mostly juveniles, are caught in nets each year.

IUCN classifies those fish as a least concern (LC). Because they are bottom-dwelling creatures, the probability of catching such organisms is relatively low. Is one of the few shark species affected only very slightly by human activity.