The nurse shark, also known by its scientific name Ginglymostoma cirratum, is a species of shark and the sole member of its taxonomic genus Ginglymostoma, a word that roughly translates from ancient Greek to "hinge mouth." The origin of the name "nurse shark" is under dispute, but most likely comes from the Old English word "hurse," which means "sea-floor shark."

The nurse shark occupies shallow tropical or subtropical waters relatively near the coast. It prefers depths of about three feet, but may be found in waters as deep as about 250 feet. The nurse shark resides, on the western Atlantic coastline, as far north as Rhode Island in the United States and as far south as southern Brazil; on the eastern Atlantic coastline, around Cameroon and Gabon but possibly further north and south; in the eastern Pacific coastline, as far north as southern Baja California and as far south as Peru; and surrounding the Carribean islands.

On average, nurse sharks measure between seven and a half and ten feet in length, and weigh between 200 and 330 pounds. However, at their largest, nurse sharks can be huge, measuring 14 feet in length and weighing a whopping 730 pounds. Nurse sharks are made distinctive by their somewhat puckered mouths and very large tail fins. Their skin is brown-grey in color and smooth to the touch.

Nurse sharks feed primarily on fish, squid, and shrimp. They largely consume dormant fish, and tend to do so by sucking their food into their large throats. Though crustaceans are not its preferred food, the nurse shark has a very powerful jaw that makes it well-equipped to eat things like shellfish and even coral. Nurse sharks have been spotted resting on the ocean's floor while propping themselves up with their fins; it is suspected that this behavior is a means of luring crustaceans into a sort of false shelter so that the nurse shark can better seize them as prey.

Like many animals, nurse sharks have a defined mating season, which occurs from late June to late July. After this time, female nurse sharks gestate for about six months, Nurse sharks are ovoviviparous, meaning that pregnant nurse sharks produce eggs that actually hatch in utero, where the shark pups continue to develop for a period of time until a live birth occurs. A female nurse shark can only give birth every two years, and typically delivers between 21 and 29 pups at a time.

Nurse sharks are slow-moving animals that do not tend to be aggressive. For this reason, they do not pose a substantial risk to humans. However, they have been known to bite humans who step on them inadvertently or disturb them as an act of self-defense. Therefore, if you encounter a nurse shark, you likely do not need to worry, but it is wisest to leave it be.

About the Author - Wildlife Animals educational articles about wild animals and themed wild animals gifts. http://www.wildlife-animals.com