Frequently found under rock or reef ledges. Carnivorous with well-developed organs for scent and vibration detection. Like all sharks, the nurse shark has a skeleton of cartilage rather than bone. Instead of scales, its body is covered with tiny razor-sharp denticles. The teeth are specialized forms of denticles. Sharks must continually swim or will slowly sink because they have no air bladder. Edibility is poor. Range is from Rhode Island to Brazil, including the Gulf of Mexico.