Short-tail Stingray, Smooth Stingray.
A very large, thick bodied stingray with a kite-shaped disc that is slightly wider than long; disc width approximately 1.1-1.2 x length. Snout short and obtuse with a small protruding tip. Anterior margins of disc mildly convex. Pectoral fin apexes narrowly rounded. Pelvic fins relatively small with narrowly rounded apexes.
Eyes relatively small. Snout length 2-2.2 x combined eye and spiracle length.
Mouth contains 5-7 oral papillae. Deep labial furrows around mouth. Lower jaw weakly convex. Extremely broad, skirt shaped nasal curtain with a fringed margin. Nostrils oval shaped. Dorsal surface lacks dermal denticles but specimens exceeding 45cm DW have a row of stellate thorns and tubercles on midline of tail from base to caudal spine. Sharp thornlets cover tail beyond caudal spine. Tail relatively very wide, and depressed at base. Tail length usually shorter than disc width. Dorsal finfold reduced to a hard ridge.
Dorsum uniformly grey, slate grey, grey-brown, or almost black, with a row of small white pores on each pectoral fin that start close to mid points of the anterior pectoral fin margins, and run diagonally backwards, parallel to the pectoral fin posterior margins. Ventrum white; usually with a dusky disc margin.
Maximum disc width 210cm. Disc width at birth 32-36cm.
Temperate seas. On soft substrates, sometimes adjacent to reefs. From shallow bays (including estuaries) to at least 480m.
The short-tail stingray has a patchy temperate distribution.
In the southern hemisphere it occurs around New Zealand (including the Kermadec and Chatham Islands), along the entire southern coast of Australia from southern Queensland to Shark Bay, Western Australia, and in southern Africa from the Zambezi River in Mozambique to Cape Town in South Africa.
In the northern hemisphere it occurs in Japan and St Peter the Great Bay in eastern Russia. Until recently, the northern population was considered a separate species (Dasyatis matsubarai) but recent genetic studies have confirmed that the southern and northern populations are the same species.
The short-tail stingray 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.
Duffy, C.A.J., Paul, L.J. & Chin, A. 2016. Bathytoshia brevicaudata. The IUCN Red List of Threatened Species 2016: e.T41796A68618154. https://dx.doi.org/10.2305/IUCN.UK.2016-1.RLTS.T41796A68618154.en. Downloaded on 01 February 2021.
Matrotrophic aplacental viviparity. Litter size 6-10.
Diet consists of invertebrates and small fishes.
Forms large mating aggregations, during which many males will follow a single female in an effort to mate with her.
Average depth changes by region. In South Africa short-tail stingrays are mostly found between 180-480m. In Australia they are generally shallower than 150m. This may reflect food availability in each region.
Reaction to divers
Shy but approachable with non-aggressive movements. Generally bolts if approached closely.
Short-tail stingrays are regularly encountered at numerous sites in southern Australia. In that region, they are usually referred to as smooth stingrays or bull rays.
Although I have seen Short-tail rays on almost every dive at Rottnest Island in Western Australia, I found these big rays very unapproachable at that location. Further south at Hamelin Bay, short-tail stingrays and southern eagle rays swim right up to the beach to forage for scraps discarded by fishermen. At this location the rays have become habituated to humans; accepting fish scraps by hand and allowing tourists to pet them.
While they can be encountered just about anywhere in southern Australia, for guaranteed encounters head to Narooma Harbour and Montague Island. Both have large populations of short-tail stingrays. They are also common under the jetties/piers near Melbourne, such as Flinders and Blairgowrie Piers. (Intel. Nigel Marsh)
At the Poor Knights Islands off New Zealand, short-tail stingrays form massive mating aggregations during the summer, where one large female is pursued by scores of males. Timing a visit to coincide with the event is difficult.
Elsewhere in NZ, short-tail stingrays can be found in shallow harbours/estuaries, in the summertime from Nov-end to March. There are usually a few around Tauranga harbour, and in nearby bays around Motiti Island. (Intel. Helen Cadwallader)