The fourth and fifth gill slits are very close together. Behind each eye there is a spiracle, an organ that takes in water used for breathing when the shark rests at the bottom. The skin is dark gray-brown on top and some nurse sharks, especially the young, have spots. The nurse shark is smooth to the touch, unlike most sharks. They are nocturnal hunters that rest during the day in groups.
Nurse sharks do well in captivity.
Most hunting is done at night. The nurse shark is a large, sluggish, docile shark that is generally harmless unless provoked. They are sluggish or rest during the day, sometimes piled together on the bottom. They are bottom-dwellers, living near sandy beaches, mudflats, and sandbars. They are common in coral reefs.