page_title: Reticulate whipray
section_title: Biology and ecology
hierarchical_section_title: Reticulate whipray / Biology and ecology
caption_attribution_description: Honeycomb stingrays (Himantura uarnak) in Darwin
context_page_description: The reticulate whipray or honeycomb stingray is a species of stingray in the family Dasyatidae. It inhabits coastal and brackish waters across the Indo-Pacific region from South Africa to Taiwan to Australia, favoring sandy habitats. A large species reaching 2 m in width, the reticulate whipray has a diamond-shaped pectoral fin disc and an extremely long tail without fin folds. Both its common and scientific names refer to its ornate dorsal color pattern of many small, close-set dark spots or reticulations on a lighter background. However, the reticulate whipray is only one of several large spotted stingrays in the Indo-Pacific which, coupled with the variability of its coloration with age and locality, has resulted in a great deal of taxonomic confusion.
  Often encountered resting on the bottom during daytime, the reticulate whipray is a predator of bottom-dwelling invertebrates and bony fishes. Like other stingrays, it is aplacental viviparous, with the developing embryos nourished at first by yolk and later by histotroph. Females bear litters of up to five pups in summer, following a gestation period of a year.
context_section_description: During the day, the reticulate whipray is generally inactive and spends much time resting motionless on the sea floor, sometimes buried in sand. In Shark Bay, Western Australia, this ray can be found resting singly or in small groups in very shallow water during high tide. Its lateral line extends to the tip of its extremely long tail, giving it advance warning of approaching predators such as bottlenose dolphins (Tursiops aduncus) and hammerhead sharks (Sphyrna). The cowtail stingray (Pastinachus sephen) prefers to rest with the reticulate whipray over others of its own species, because the whiprays' longer tails grant them superior predator detection. These mixed-species groups often settle into a "rosette" with their tails pointing radially outward for maximum predator awareness.
  The reticulate whipray preys on a variety of benthic and neritic organisms, including crabs, shrimps, mantis shrimps, bivalves, gastropods, worms, jellyfish, and bony fishes. In the western Indian Ocean, about two-thirds of its diet consists of fishes, in particular ponyfish and anchovies, with shrimps and other crustaceans making up most of the remainder. By contrast, rays in Australian waters are apparently not piscivorous, and are known to consume penaeid prawns. Known parasites of this species include Anthrobothrium loculatum, Dendromonocotyle colorni, Halysiorhynchus macrocephalus, Monocotyle helicophallus, M. multiparous, and M. spiremae, Thaumatocotyle australensis, and Tylocephalum chiralensis.
  Like other stingrays, the reticulate whipray is aplacental viviparous: the developing embryos are initially sustained by yolk, which is later supplanted by histotroph ("uterine milk", enriched with proteins and lipids) produced by the mother. Females give birth to up to five pups in the summer, after a year-long gestation period. Off South Africa, the newborns measure 28–30 cm (11–12 in) across and sexual maturation is attained at a disc width of approximately 1 m (3.3 ft), which corresponds to an age of 4-5. Off Australia, the newborns measure 21–28 cm (8.3–11.0 in) across, with males reported to mature at 82–84 cm (32–33 in) across. The juveniles of this species, H. leoparda, and H. undulata differ in birth size, disc shape, denticle development, and amount of spotting, and are in fact more distinct from each other than are adults of the three species. Shark Bay may serve as a nursery area for young rays.
caption: Two reticulate whiprays and other fish being fed on a beach near Darwin, Australia.
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