Physical Attributes of the Goblin Shark

Many sharks look sinister. The Goblin Shark looks sinister and grotesque. It has a ridiculously long snout, much longer than other sharks have. This sharp-looking soft fleshed “nose”, the rostrum, hovers over a collection of pointed teeth in a protractible jaw. Protractible means that the Goblin Shark’s jaw is usually tucked within its streamlined body but can be suddenly thrust forth. When the shark attacks the jaws thrust out and open wide as a muscular tongue shoots forth to suck prey between its gaping needle-like outer teeth and onto the crushing bony plate that is composed of the fused teeth of its inner jaw.

The fins of the Goblin Shark are not like those of many other sharks, being rounded and held close to its body, rather than sharply upright. The anal and pelvic fins, the ones on the lower half of its body, are significantly larger than the dorsal fin, the fin on top. Its physique resembles those of the languid, slow moving sharks, rather than the fast swimmers. The Goblin is pinkish, because the blood in its capillaries shows through its soft translucent skin, but its fins are edged with peacock blue. Goblin Sharks lack a nictating membrane, the transparent inner eyelid that protects the eyes of many other shark species, and they have “nostrils” on either end of their mouths, at the base of the rostrum.

This baby pink monster, Mitsukurina owstoni, gets its genus name from Kakichi Matsukuri, the zoologist who took the first specimen to David Jason be identified and its species name from the wildlife collector Allan Owston, who acquired the first specimen from a Japanese fisherman. Its common name in English is a translation of tenguzame, a supernatural creature of Japanese folklore that had a long nose and was a defender of sacred sites.

This shark may grow up to 12 feet long or more, but the average of known specimens is about 5 feet. It can weigh up to 350 pounds. Its size and weight at birth are unknown. Its density is about that of seawater. It is a denizen of the outer continental shelves, probably worldwide, living at depths of 60 to 280 meters (about 200 to 920 feet), feeding in mid-water, and hunting in the zone where very little sunlight penetrates. It probably finds its prey with electrodetection organs in its rostrum in the semi-darkness where it hangs, although it can see, too. It may sieze its prey from ambush, hovering in the dimness and then suddenly swallowing up such swimmers as are migrating up or down between darkness and light. So its physical attributes make sense: it is built to hide in the dimness of the middle levels of the sea, to sense and then seize its passing prey.

This bizarre seeming fish is not a danger to humans, living as it does in realms we seldom visit. No Goblin Shark has yet survived long in captivity, nor has its behavior in the wild been well observed. Much of their life-cycle remains a mystery to us. They are sometimes taken as bycatch, fish caught by fishermen in search of other prey, but they are not sought after. Their flesh is occasionally dried and salted, but they are not generally considered a food fish. A few collectors treasure the skeletons of their startling jaws.

http://www.elasmo-research.org/education/shark_profiles/m_owstoni.htm
http://www.youtube.com/watch?v=RnOikVwoT88
http://www.youtube.com/watch?v=LGOb1KLdWGE&NR=1
http://www.fossilsonline.com/index.php?main_page=index&cPath=3
http://www.flmnh.ufl.edu/FISH/Gallery/Descript/GoblinShark/GoblinShark.html