The largest ray at the Aquarium is the roughtail ray at about 200 lbs. K Stingrays are surprising animals. Most have a flat body with wide pectoral fins that resemble wings. There are two smaller pelvic fins and a long, thin, whiplike tail that may or may not have a small dorsal fin or two on top. Rays have skeletons of cartilage rather than bone.
Cartilage is more flexible and lighter in weight than bone.
The skin covering of rays is usually soft and smooth, the they range in color from light to dark grays and brown. Some, like the spotted eagle rays, have a pattern of spots. The underside is usually lighter, a pattern called countershading that is found in many sea creatures and in some birds also. Most rays have a hard spine on top of the tail. The spines have serrated edges with sharp points that point back toward the base.