Tuesday, February 1, 2011
February 1, 2011 : Nurse Shark
The nurse shark, Ginglymostoma cirratum, is a shark in the nurse sharks (Ginglymostomatidae) family, the only member of its genus Ginglymostoma. Nurse sharks can reach a length of 4.3 m (14 ft) and a weight of 330 lbs (150 kg).
The nurse shark is a common inshore bottom-dwelling shark, found in tropical and subtropical waters on the continental and insular shelves. It is frequently found at depths of one metre or less but may occur down to 75 m. Its common habitats are reefs, channels between mangrove islands and sand flats. It occurs in the Western Atlantic from Rhode Island down to southern Brazil; in the Eastern Atlantic from Cameroon to Gabon (and possibly ranges further north and south); in the Eastern Pacific from the southern Baja California to Peru; and around the islands of the Caribbean.
Nurse sharks are nocturnal animals, spending the day in large inactive groups of up to 40 individuals. Hidden under submerged ledges or in crevices within the reef, the nurse sharks seem to prefer specific resting sites and will return to them each day after the night's hunting. By night, the sharks are largely solitary; they spend most of their time rifling through the bottom sediments in search of food. Their diet consists primarily of crustaceans, molluscs, tunicates, sea snakes, and other fish, particularly stingrays.