Nurse shark

Photo: Gonzalo Romero · CC BY

Bottom-dwelling, largely nocturnal sharks that spend much of the day resting in groups under coral ledges or on sandy substrate. Nurse sharks are identifiable by their broad, flattened heads, small eyes, and twin nasal barbels used to sense prey in sand and rubble. They feed on crustaceans, molluscs, and small fish, using powerful suction to extract prey from crevices. Among the least threatening sharks to divers — slow-moving, benign, and tolerant of close approach when resting. They should not be handled; bites from provoked individuals, while rare, are powerful.