Rays of the WorldRays are among the largest fishes in the sea and have colonized all oceans. The first cousins of sharks, rays evolved from early Mesozoic or late Paleozoic shark like ancestors. They also share with sharks many life history traitsall are carnivores or scavengersand a multitude of morphological and anatomical characters, such as their skeletons built of cartilage. There are six families and 633 valid named species of rays, but additional undescribed