Nurse sharks are common in the tropical waters of the western Atlantic. They are non-migratory. In fact, it seems as though they hardly move at all during the daytime, and researchers believe that they inhabit one location for much of their lives. They can frequently be found sitting motionless, often piled on top of one another, while resting on the ocean floor, in caves or under coral reefs. They are nocturnal hunters, foraging at night for bottom-dwelling marine life such as spiny lobsters, squid, mollusks and a variety of reef dwelling animals. Tagged individuals have been identified returning repeatedly to the same caves or resting sites at the end of each night’s hunting. Unlike most other sharks, the nurse shark clearly does not have to keep swimming in order to keep water circulating over its gills. Nurse sharks are able to flutter water over their gills while lying on the ocean floor.

They are comic looking creatures with very small eyes and prominent fleshy protrusions or “nasal barbels” jutting from the base of their nose. They seem to locate their prey by touch and by smell, more than sight. Nurse sharks have strong, crushing jaws designed to feed on lobsters, crabs and shrimps as well as sea urchins and another favorite food, octopi. Because of this fishermen frequently consider them as competitors for limited shrimp and lobster catches. The nurse shark’s role in the food chain was clearly established in the Florida Keys, where they have been heavily exterminated by fishermen. Once the nurse sharks dwindled, the octopus population grew rapidly, devouring many more shrimp and lobsters than the nurse sharks consumed. Nurse sharks are also vulnerable to human impact on the environment because of their slow growth pattern of development. Nurse sharks take many years to become mature, reproductive adults. After reaching adulthood, they breed infrequently and only produce a few offspring at a time.