The viper dog fish is a rare deep sea shark.  Its maximum length is 47cm. It is found off the coast of Wakayan and Tokushima and Japan in the northern Pacific ocean. It has been seen once in Hawaii.  It is the only species in the genus Trigonopnathos that lives in depths of 330 and 360m.  Little is known about this type of shark. There are more than 360 described species of sharks, there are eight orders of sharks: Hexanchiformes, Squaliformes, Pristiophoriformes, Heterodontiformes Orectolobiformes, Carcharhiniformes, Lamniformes. But researchers think that there are more sharks that have not been discovered yet.

Sharks are the best hunters in the world. Their hunger can be satisfied in one meal. Even their pups go looking for food. The shark's food lasts a long time in their stomach because they use little energy to swim. Sharks are strong living creatures. Sharks take care of themselves better than any other living creature. Sharks never get cancer.  Their cartilage is being studied to develop anti-cancer drugs. Sharks have been around for more than 300 million years, even longer than dinosaurs. Sharks bodies are heavier than the sea so if they stop moving they will sink. To live they have to keep swimming.

Author: Elijah L.
Published: 02/2009

Sources:

http://en.wikipedia.org/wiki/Viper_dogfish Animals book "Trigonognathus kabeyai". FishBase. Ed. Ranier Froese and Daniel Pauly. May 2006 version. N.p.: FishBase, 2006.

Photo Credit: http://www.science.fau.edu/sharklab/photos/sharks/vipershark