Honeycomb Whipray.

The honeycomb stingray or reticulate whipray, Himantura uarnak, is a species of stingray in the family Dasyatidae, named for the striking pattern of black lines and dots on its back. Other common names include leopard stingray, longtail stingray, and marbled stingray; some of these names are shared by other, similarly colored stingrays. The taxonomy of this species merits further examination, as it may represent a species complex. It is found in shallow marine waters throughout the Indo-Pacific and feeds on benthic fishes and invertebrates. This species is of importance to commercial and recreational fisheries across its range.

Distribution and habitat

The honeycomb stingray is widely distributed in the Indo-Pacific region, from the eastern coast of South Africa and the Red Sea to Australia and French Polynesia, including Mozambique, India, Indonesia, the Philippines, and Taiwan. It has also colonized the eastern Mediterranean Sea through the Suez Canal. This species is found in shallow waters from the intertidal zone to a depth of 50 meters (160 ft), at temperatures of 23-26° C (73-79° F). It is commonly encountered over soft sediment around beaches, estuaries, lagoons, and coral reefs.

Description

This large species has been reported to a disk width of 2 meters (6.6 ft) and a weight of 120 kg (260 lbs). With its very long tail, it reaches 6 meters (20 ft) in length. The pectoral fin disk is thick and diamond-shaped, wider than it is long, with a broad triangular snout. The mouth is relatively small, with 4-5 papillae on the floor. There are 26-40 rows of teeth in the upper jaw and 27-44 rows in the lower jaw. The extremely thin, whip-like tail measures 3-3.5 times the length of the body when intact. The tail mounts a single serrated spine and no fin folds. A broad band of flattened, heart-shaped dermal denticles extend from between the eyes to over the base of the tail, becoming more dense as the ray ages.
Several color morphs are known for the honeycomb stingray, which may turn out to be distinct species.
Generally, juveniles are yellow to brown with a closely spaced pattern of dark spots on the dorsal pattern and around 7 spots in a line between the spiracles. In adults, the dorsal ornamentation becomes denser, forming a fine, complex pattern of dark brown lines and spots on a white to orange background. The underside is pale and unadorned. The tail has alternating black and white bands past the spine.

Biology and ecology

The honeycomb stingray feeds on a wide variety of small bony fishes and invertebrates. In the western Indian Ocean, it feeds mostly on fishes (especially ponyfish and anchovies), while also taking lesser amounts of shrimps and other crustaceans, and molluscs. Off Australia, this species is a predator of penaeid prawns and is apparently not piscivorous. Other reported food items include worms and jellyfish.
The extremely long tail of the honeycomb stingray is equipped with mechanoreceptors that give it advance warning of approaching predators. The cowtail stingray (Pastinachus sephen) is known to preferentially rest in mixed-species groups with this ray, due to its superior predator detection. Known parasites of this species include Anthrobothrium loculatum, Dendromonocotyle colorni, Halysiorhynchus macrocephalus, Monocotyle helicophallus, M. multiparous, M. spiremae, Thaumatocotyle australensis, and Tylocephalum chiralensis.
As in other members of its family, the honeycomb stingray is ovoviviparous, with the embryos being sustained by a yolk sac in early development and by nutrient-rich histotroph ("uterine milk") delivered through specialized structures by the mother in late development. Females give birth to litters of 3-5 young in the summer, after a year-long gestation period. The newborns measure 28-30 cm (11-12 in) across. Sexual maturation is attained at a disk width of around a meter (3.3 feet), corresponding to an age of 4 or 5.

Relationship to humans

This species is popular with recreational anglers and is also frequently caught by beach seines, tangle nets, bottom trawls, and longlines. Though sometimes eaten, it is not valued as a food fish and is usually released. This species is also utilized for its skin and cartilage, as well as in Chinese medicine. Its tail may be sold as a curio. The conservation status of this species has not yet been evaluated by the World Conservation Union.