Jenkins' Whipray

The pectoral fin disc of the Jenkins' whipray is diamond-shaped and rather thick in the center, measuring 1.1–1.2 times wider than long; the outer corners of the disc are broadly rounded. The anterior margins of the disc are nearly straight and converge at a very obtuse angle on the snout, which has a barely protruding tip. The eyes are medium-sized and closely followed by larger spiracles. A short, broad curtain of skin with a finely fringed posterior margin is present between the long, thin nostrils. The mouth is wide and gently arched, and contains four papillae (nipple-shaped structures) on the floor, the inner pair of which is shorter than the outer.

The Jenkins' whipray is rather common, with a wide but patchy distributed in the tropical waters of the Indo-Pacific. It occurs off southeastern Africa (including Madagascar), the Socotra Islands near Yemen, South and Southeast Asia (including the Philippines), New Guinea, and northern Australia from Ningaloo Reef to the Gulf of Carpentaria. This bottom-dwelling species is generally found close to shore in water under 50 m (160 ft) deep, though it has been recorded as far down as 100 m (330 ft) off northwestern Australia. It prefers sandy or silty bottoms, often in lagoons, and has been known to enter brackish water.

The Jenkins' whipray may be encountered alone or in groups; there is some evidence of segregation by sex. Small teleost fishes form a substantial portion of its diet, while crustaceans are also taken. One individual has been observed accompanying a smalleye stingray (Dasyatis microps) off Tofo, Mozambique. Known parasites of this species include the tapeworms Dollfusiella ocallaghani, Parachristianella baverstocki, P. indonesiensis, and Pterobothrium platycephalum. As in other stingrays, the Jenkins' whipray is aplacental viviparous: the developing embryos are sustained at first by yolk, which is later supplanted by histotroph ("uterine milk") produced by the mother. The newborns measure 20–27 cm (7.9–10.6 in) across, and males reach sexual maturity at 75–85 cm (30–33 in) across.

Because of its large thorns, the Jenkins' whipray is highly prized for its skin; the meat and cartilage may also be utilized. It is frequently taken intentionally and incidentally across much of its range by intensive coastal fisheries, using tangle nets, bottom trawls, seine nets, and to a lesser extent longlines. Particularly large numbers are caught by an Indonesian commercial gillnet fishery targeting wedgefishes, that operates in the Arafura Sea and increasingly, illegally, in Australian waters. Although species-specific data is lacking, this fishery has caused a substantial decline in overall stingray populations. Off northern Australia, the Jenkins' whipray is relatively protected; it is thought to contribute minimally to the bycatch of the Northern Prawn Fishery (NPF) since the mandatory introduction of Turtle Excluder Devices (TERs).