Nurse Shark (Ginglymostoma cirratum)
The Nurse Shark can be seen 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. Its common habitats are reefs, channels between mangrove islands and sand flats.
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.
They are thought to take advantage of dormant fish which would otherwise be too fast for the sharks to catch; although their small mouths limit the size of prey items, the sharks have large throat cavities which are used as a sort of bellows valve. In this way, nurse sharks are able to suck in their prey. Nurse sharks are also known to graze algae and coral. Nurse sharks have been observed resting on the bottom with their bodies supported on their fins, possibly providing a false shelter for crustaceans which they then ambush and eat.
The nurse shark is not widely commercially fished, but because of its sluggish behavior it is an easy target for local fisheries. Its skin is exceptionally tough and is prized for leather; its flesh is consumed fresh and salted and its liver is utilized for oil. It is not taken as a game fish. It has been reported in some unprovoked attacks on humans but is not generally perceived as a threat.
Information courtesy of wikipedia.org/wiki/nurse_shark
Photo courtesy of the-shark-side-of-life.com