SHORT-TAIL STINGRAY

Short-tail Stingray. Bathytoshia brevicaudata.

View more Short-tail Stingray images in the Shark Pictures Database

Common Names: Shorttail Stingray, Short-tail Stingray, Smooth Stingray, Pitted Stingray, Thorntail Stingray.

Latin Name: Bathytoshia brevicaudata

Synonyms: Dasyatis brevicaudata, Dasyatis thetidis, Dasyatis matsubarai.

Family: Dasyatidae

Identification: Rhomboid disc; wider than long. Anterior disc margins almost straight with rounded tips. Snout obtuse. Dorsum smooth, dark brown to dark purplish-grey with a diagonal line of small white spots on each pectoral fin from level with the eyes towards the tail. Ventrum pale, sometimes mottled near the margin. Center line of tail contains a row raised thorns between base and barb. Beyond barb/sting, tail tapers quickly to a short thin whip. Tail usually shorter than disc with a short, prominent ventral finfold.

Size: Maximum recorded disc width 210cm.

Habitat: Sand and rocky bottoms often near rocky reefs and continental drop offs. Intertidal to 480m. Observed in shallow bays in Australia. More frequent between 180-480m in South Africa. Seen mating in cave systems in New Zealand.

Distribution: Temperate seas. Mostly in the southern hemisphere in southeast Africa, Australia except north coast, New Zealand and southern Oceana. Also from the Northern Hemisphere around the Japanese archipelago and Eastern Russia.

Diet: Moves into shallow water in Australia at flood tide to feed. Feeds on bony fishes, bivalves, squid, and crustaceans.

Reproduction: Viviparous. In NZ males have been observed biting and holding onto the much larger females pectoral fin for hours at a time. During actual copulation the male flips upside down under the female and inserts one clasper. He then beats his pectoral fins up and down and in so doing moves his clasper in and out of the females cloaca. During maturation males have been observed nudging the female which may stimulate the birthing process.

Conservation Status: The IUCN lists the Shorttail Stingray as LEAST CONCERN. This species is taken as bycatch in trawl, Danish seine, longline and purse seine fisheries, but is most often discarded, although small quantities are sold in Australia when caught as bycatch (Lamberth 2006, Last and Stevens 2009). This species is a minor bycatch component (4.3% of the elasmobranch catch) of the New South Wales commercial line fishery with approximately 30% of these rays being retained (Macbeth et al. 2009). The species is also taken as bycatch (7% of the elasmobranch catch) in the Southwest Longline fishery off Western Australia (Jones et al. 2010). An estimated 88.5 tonnes were caught annually in the Australian Southern and Eastern Shark and Scalefish Fishery between 2000 and 2006, of which ~5% was retained for market (Walker and Gason 2007). It is commonly taken by recreational line fishers, either by surfcasting or line fishing from boats and sometimes speared or harpooned for sport. It is often released but sometimes retained for their flesh, or for angling competitions. It is occasionally captured in beach meshing/shark control gear off South Africa. Commercial and recreational fishers regularly amputate stingrays' tails before releasing them to reduce the risk of injury. The relatively large number of Short-tail Stingrays seen by divers without tails suggests they survive capture and release well. A small number of rays are caught for exhibition in public aquaria.

Photographs: Roe Reef, Rottnest Island, Western Australia.

Similar species: Matsubara's Stingray (Dasyatis matsubarai) has a very similar appearance including the rows of white spots, but is only known from Japan and possibly Thailand.

Reaction to divers: The shorttail stingray moves away when approached but may ignore divers when concentrating on mating.

Diving logistics: Although I have seen Shorttail rays on almost every dive at Rottnest Island I found these big rays very unapproachable. A far better location to try would be the Poor Knights Marine Reserve off of New Zealand where hundreds of Shorttail stingrays Congregate to mate each summer.

Citations:

Duffy, C.A.J., Paul, L.J. & Chin, A. 2016. Bathytoshia brevicaudata. The IUCN Red List of Threatened Species 2016: e.T41796A68618154. http://dx.doi.org/10.2305/IUCN.UK.2016-1.RLTS.T41796A68618154.en. Downloaded on 22 October 2017.