Batoidea is a superorder of cartilaginous fish containing more than 500 described species in thirteen families. They are commonly known as rays, but that term is also used specifically for batoids in the order Rajiformes, the "true rays". Batoids include stingrays, skates, electric rays, guitarfishes and sawfishes. Anatomy Batoids are flat-bodied, and, like sharks, are a species of cartilaginous marine fish, meaning they've a boneless skeleton made of a tough, elastic substance. Most batoids ha… (More on Batoidea)