The Whiptail Stingray Family – Dasyatidae
Diamond Stingray, Hypanus dipterura, a representative member of the Whiptail Stingray or Dasyatidae Family.
The fish of the Whiptail Stingray or Dasyatidae Family are a group of marine fish found in shallow waters of tropical and warm temperate areas of the Atlantic and Pacific Oceans. In Mexico they are known as rayas látigo. Globally, the Dasyatidae Family includes seventy species with thirty-eight species that have been placed in the genus Hypanus, six of which are found in Mexican waters, four in the Atlantic and two in the Pacific.
The Whiptail Stingrays are moderate to very large rays ranging in size from 30 cm (12 inches) to 2 meters (6 feet 6 inches). They are uniformly dark brown dorsally and off-white ventrally. They are characterized by an angular to rounded very flattened disc with a width that is no more than 1.3X the disc length. Their pectoral fins are continuous with the head. Their eyes and spiracles are on the dorsal side and their mouth and five pairs of gill openings are on the ventral side. They have small teeth set in many series that form bands on each jaw. They have no caudal or dorsal fins. Their tail is slender and whip-like being longer than the disc and has one or more serrated venomous spines that can measure up to 40 cm (16 inches) in length on its upper surface, making them dangerous to humans. The skin on their disc can be smooth or armed with tubercles, thorns, or denticles.
The Whiptail Stingrays are found in coastal waters and estuaries, off beaches, and in river mouths generally over sandy or muddy bottoms spending (with one exception) a large portion of their time half-submerged in the substrate (benthic) watching for prey. They have a keen sense of sight, hearing, smell, taste, and touch with exceptional electrical sensitivity exceeding that of all other animals. They feed on a variety of sand and mud-dwelling organisms including crabs, mollusks, shrimps, worms, and fish. The Pelagic Stingray, however, consumes crustaceans, jellyfish, squid, and fish. They are preyed upon by a wide variety of the larger sharks including the Great Hammerhead. Occasionally, Remoras are found attached to the larger species. They utilize their venomous stinger for protection. Most stingrays have drab coloring allowing them to blend in with sandy or muddy bottoms. They are live-bearing fish with reproduction occurring via aplacental uterine viviparity which involves internal fertilization; they develop from egg to juvenile inside their mother’s uterus where they are fed by their mother’s milk for a period of two to four months. Each female produces one litter per year, usually bearing two to six young. Newborns arrive looking like rolled up cigars that are fully developed miniature adults. They are born in low numbers but in large sizes and are able to feed and fend for themselves from birth, assuring the continuity of the species. They are generally poorly studied and their lifespan is generally unknown but they are known to be slow growing, slow to mature, with small litter sizes, and long-lived, thus prone to overfishing. They are considered either Endangered or Vulnerable to potential extinction. They date to the Cretaceous Period, 65 million to 145 million years ago.
The Whiptail Stingrays have been important food sources for a variety of global cultures for eons. They are sold commercially in local markets throughout their ranges. Their tail spines have been used for spear tips, daggers, or whips. Various components of these rays have been used for a wide variety of medical purposes such as skin replacement, tumor suppression, cancer treatment as well as for gelatin and liver oil production. They can also be found in public aquarium exhibits. They are famous for wreaking havoc with oyster farms and cultivated clam beds. And of course, they are known for inflicting excruciating pain and even death in humans with their stingers.
There are five members of the Whiptail Stingray or Dasyatidae Family currently presented in this website: