Dasyatis
Himantura
Pastinachus
Pteroplatytrygon
Taeniura
Urogymnus
See text for species.
Dasyatidae is a family of rays, cartilaginous marine fishes, related to skates and sharks.
Dasyatids are common in tropical coastal waters throughout the world, and there are fresh water species in Asia (Himantura sp.), Africa, and Florida (Dasyatis sabina). Most dasyatids are neither threatened nor endangered. The species of the genera Potamotrygon, Paratrygon, and Plesiotrygon are all endemic to the freshwaters of South America.
Dasyatids swim with a "flying" motion, propelled by motion of their large pectoral wings (commonly mistaken as "fins"). Their stinger is a razor-sharp, barbed, or serrated cartilaginous spine which grows from the ray's whip-like tail (like a fingernail), and can grow as long as 37 cm (about 14.6 inches). On the underside of the spine are two grooves containing venom-secreting glandular tissue. The entire spine is covered with a thin layer of skin called the integumentary sheath, in which venom is concentrated. This gives them their common name of stingrays, but the name can also be used to refer to any poisonous ray.
Some adult rays may be no larger than a human palm, while other species, like the short-tail stingray, may have a body of six feet in diameter, and an overall length, including their tail, of fourteen feet.