The nurse shark (Ginglymostoma cirratum) is a bottom-dwelling shark, and is the only known species in the genus Ginglymostoma. They range in length from 2.1–2.7 metres (6 ft 11 in – 8 ft 10 in), and weigh 75–120 kilograms (165–265 lb).Nurse sharks feed on crustaceans, mollusks, sea snakes, fish, coral, and tunicates.The Nurse shark is common in the coastal tropical and subtropical waters of the eastern Pacific and the Atlantic Ocean.Nurse sharks are nocturnal, and are very sluggish and are harmless unless bothered.