Blue-spotted stingray  (Taeniura lymma)

This colourful stingray is immediately recognisable by the large, bright, iridescent blue spots that adorn its oval, elongated body (3) (4). Distinctive blue stripes also run along either side of the tail, which is equipped with one or two sharp venomous spines at the tip, used by the ray to fend off predators (5). Indeed, the brightly-coloured skin acts as ‘warning colouration' to alert other animals that it is venomous (6). The snout is rounded and the mouth is found on the underside of the body, along with the gills (5), perfect for scooping up animals hiding in the sand (6). Two plates exist within the mouth that are adapted for crushing the shells of crabs, prawns and molluscs (5). The upper surface of the body disc is grey-brown to yellow, olive-green or reddish brown, while the underside is white (3). Thus, when viewed from below the white belly blends in with the sunny waters above and when viewed from above, the dark, mottled back blends in with the dark ocean floor below (6).

Found in the Indo-West Pacific: ranging from South East Africa and the Red sea to the Solomon Islands, north to southern Japan and south to northern Australia (3).

Commonly found on the sandy or rocky bottoms of coral reefs, in shallow continental shelf waters, to depths of 20 m (3) (5). While usually inhabiting the deeper reef areas, where it hides in reef caves, under tabletop corals and overhangs, this stingray moves up to shallower reef flats and lagoons at high tide. Unlike most stingrays, blue-spotted stingrays rarely bury themselves in the sand (6).

Blue-spotted stingrays live alone or in small groups (6), migrating in large schools into shallow sandy areas on the rising tide in order to feed, and dispersing back into the ocean as the tide falls to shelter in the coral crevices of the reef (5) (7). Feeding most commonly occurs during the day, but sometimes also at night (6), and the diet consists largely of worms, shrimps, crabs, molluscs and small fish (5). Prey is often detected through electroreception, a system which senses the electrical fields produced by the prey (5). Not all small fish and invertebrates are potential prey, as blue-spotted stingrays can often be found at ‘cleaning stations', areas of reef where large fish line up and tiny fish or shrimp pick off their dead skin and parasites (6).

In courtship, males often follow females, using their acutely sensitive ‘nose' to detect a chemical signal emitted by the female that indicates she is receptive. Breeding occurs from late spring through the summer, and gestation can last anything from four months to a year (5). Reproduction is ovoviviparous, meaning females give birth to live pups that have hatched from egg cases inside the uterus (6). Up to seven pups are born per litter and each juvenile is born with the distinctive blue markings of its parents in miniature (7).

Despite being both wide-ranging and common, the blue-spotted stingray is subject to a variety of human-imposed threats (1). Widespread destruction of coral reef habitat probably poses the most significant threat to the species (1). Harm is caused by poisoning through farm pesticides and fertilizers running into the sea, by dynamite fishing, and by cyanide, used to capture reef animals for the pet trade (6). This ray is hunted throughout its range by inshore fisheries and its beautiful colouration makes it an attractive candidate for an aquarium pet (5) (6). However, this species does not survive well as a pet, outgrowing most home aquariums (6). With such a low reproductive rate, consisting of long gestation periods and small litters, the blue-spotted stingray is particularly vulnerable to population collapses caused by over-fishing, habitat loss and the pet trade (5).

Presently, this stingray is classified only as Lower Risk/near threatened (LR/nt) on the IUCN Red List 2004, and no direct conservation measures are currently in place for the species (1).

For further information on the blue-spotted stingray see:

• Animal Diversity Web:
  http://animaldiversity.ummz.umich.edu/site/index.html
• FishBase:
  http://www.fishbase.org/search.php
• Shedd: The World's Aquarium:
  http://www.sheddaquarium.org/sea/fact_sheets.cfm?id=109

For more information on sharks and their conservation see:

• Project Aware
  http://www.projectaware.org/

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk