Pelagic Stingray

Dasyatis violacea

• Rare
• Pelagic at surface to 250 m
• Total length to 98 cm
• Both surfaces uniform dark purple in colour
• Broad, wedge-shaped disc
• Whip-like tail with long, stinging spine
• Lacks caudal, dorsal and pelvic fins

Description

The pelagic stingray is easily distinguished by its characteristic, serrated tail spine which is flattened dorsoventrally and attached rigidly to the skin of the tail. Cells at the base of the spine secrete a poison which can inflict exceedingly painful wounds. It is possible, as with other members of the family Dasyatidae, that new spines develop before an old one is lost. The tail itself is less than twice the length of the body, with a long, lower caudal finfold ending well forward of the tapered tip of the tail. The body of the pelagic stingray is disc-shaped and depressed but thick, with a blunt, rounded snout and angular pectorals. The mouth is small and curved, and filled with bands of small, rounded teeth with cusps, ridges, or tubercles. The eyes - located on the dorsal surface of the head along with the spiracles - are small and do not protrude. Dorsal and anal fins are absent, and pectorals are continuous anteriorly along the sides of the head. The pectoral disc is without thorns. Pelagic stingrays have no prominent markings on their skin, and vary in colour from uniformly violet or purple to dark blue-green, both on their dorsal and ventral surfaces.

Size

The pelagic stingray reaches a total maximum length (TL) of approximately 160 cm.

Range

In Canadian north Atlantic waters, the pelagic stingray is thought to be a migratory species only, with occasional incidental captures on longlines reported from the eastern edge of the Grand Bank and from Georges Bank. A small number of captures during exploratory cruises have also been noted since early records (1962, 1965). More broadly, the pelagic stingray occurs southward from Canadian waters along the coast of the United States to the Lesser Antilles. It is also found in the Pacific Ocean and the Mediterranean Sea.

Habitat

As its name suggests, the pelagic stingray occupies open surface and near surface waters, usually occurring in the first 100 m of the water column but reaching depths of 381 m. It is often reef-associated, and is perhaps the only totally pelagic member of the family Dasyatidae.

Life History

Unkown

Diet

Pelagic stingrays have a wide diet that includes coelenterates (including medusae), squid, decapod crustaceans, and fish.

Reproduction

The pelagic stingray is ovoviviparous, with embryos developing within the oviduct of the female prior to being born live. Fecundity is thought to be 1-9 young per litter, with the possibility of two litters per year.

Interaction with people

Traditionally, spines of members of this family (Dasyatidae) were used for spear tips, awls, and daggers, and are currently sold as curios. However, the pelagic stingray is of no great commercial importance, and - due to its pelagic existence - comes into contact with humans only rarely.