Stingrays

Rays are more than 500 species of flattened fish that are closely related to sharks. Rays and sharks have skeletons made of cartilage (like in your nose and ears) instead of bone and breathe through five or six gill slits.

Diet
Rays slowly swim above the seafloor, searching for clams, crabs, shrimps, squid, and fishes hidden in the sand. They use suction to pull prey into their mouths and then crush through any hard shells with rows of flattened teeth.

Stingers
Although rays are generally peaceful animals, they can sting if threatened. When an unwary swimmer steps on a ray buried in the sand, the stingray defensively reacts by stabbing with the sharp, serrated spine at the base of its tail. The spine delivers painful venom. If stung, a swimmer can lessen the pain by soaking the wounded area in extremely hot water. At the shore, swimmers can avoid being stung by shuffling their feet while wading in shallow water. Stingrays sense the vibrations of this movement and calmly swim away.