The nurse shark (Nebrius) is a genus of shark that has lived from the early Paleocene epoch, 65 million years ago, until the present day.
Nurse sharks can range in length from 75 centimeters up to 4.3 meters. Their color can vary from yellowish to dark brown, and they have powerful pectoral fins, two spineless dorsal fins (the second being smaller) aligned with the pelvic and anal fins, as well as a tail that accounts for more than a quarter of the shark's total length.
One of the distinct characteristics of the nurse shark is its mouth located far ahead of the eyes and set back from the snout, indicating that it lives and feeds along the seabed. The lower jaw features two sensory barbels that assist in locating prey hidden in the sediment. Behind each eye is a very small circular opening known as a spiracle, which is part of the shark's respiratory system. Their teeth are fan-shaped with serrated edges.
Nurse sharks are nocturnal animals that hunt for prey in bottom sediments. Their diet consists mostly of crustaceans, mollusks, invertebrates, and other fish, particularly stingrays.
