Nurse Shark
Say the word "shark" and the Great White probably comes to mind, with mental pictures of a very big mouth filled with very huge teeth. Chances are the nurse shark will probably never be mistaken for the Great White. It does have strong jaws, a wide head, and replaceable teeth that are strong enough to crush shellfish. However, this gray-brown colored creature is actually rather harmless.
The nurse shark is kind of a sluggish animal that feeds mostly on the bottom of the sea floor. It eats fish, shrimp, lobsters, and coral and generally hunts at night. During the day, nurse sharks tend to congregate in groups. Sometimes they just pile up on the sea bottom and go to sleep.
The biggest nurse sharks grow to about 14 feet long and weigh as much as 700 pounds. However, they are also as small as two feet long.
It's unclear how the nurse shark go its name. One suggestion is that the name comes from the sucking, baby-like sound the animal makes as it swims through the sea.
Even though the nurse shark has a rather docile reputation, if you are doing any Key West Diving, it is probably a good idea to swim the other way if you see one. Nurse sharks are said to become testy if they are disturbed during their daytime slumbers.