Spotted Stingaree: Urolophus gigas

Family: Urolophidae
Common name(s)

Spotted Stingaree.

Identification

A large stingaree with a circular disc that is approximately equal in length and width. Snout broadly rounded or slightly obtusely angular. Anterior margins of disc broadly convex, apices broadly rounded. Disc completely smooth.
Eyes very small; orbit length 0.16-0.25 x snout length. Spiracle large, origin below mid-eye or posterior portion of eye. Gill slit margins smooth. Mouth small. 9-12 small oral papillae on mouth floor. Nasal curtain skirt shaped, weakly flared posteriorly, slightly extended posteriorly into a lobe, posterior margin heavily fringed. No fleshy lobe on each nostril.
Tail short and broad, length 0.76-0.8 x disc length, round to somewhat oval in cross section. Dorsal fin present. Caudal fin short and deep, with a rounded tip.

Colour

Dorsum dark grey or blackish with a generally symmetrical, dense covering of irregular pale blotches containing small dark flecks. Where blotches are absent there is a dark mask across the eyes, a large dark circle on disc centre (without a white centre blotch), and a large dark vaguely triangular shape on posterior half of each pectoral fin. Pale blotches near disc margin and dorsally on tail smaller. Ventrum pale with scattered dark spots and a well defined dark disc margin.

Size

Total length 80cm. Length at birth unknown.

Habitat

Temperate seas. Found on and around rocky reefs, seagrass beds, kelp, and sand. From shallow water to 50m.

Distribution

Southeast Indian Ocean. The spotted stingaree is wide ranging in southern Australia, occurring from Lakes Entrance, Victoria westwards to Albany, Western Australia, including the northern coast of Tasmania.

Conservation Status

LEAST CONCERN

The Spotted Stingaree is infrequently caught as bycatch in the Great Australian Bight Trawl Sector of the Southern and Eastern Scalefish and Shark Fishery (SESSF) (Walker and Gason 2007). Overall, trawl effort in that sector of the fishery is low and parts of the species’ distribution are unfished or have extremely low fishing pressure (Patterson et al. 2017). The lack of trawling in Bass Strait (Patterson et al. 2017) as well as its occurrence around rocky reefs would provide it with some refuge from major fishing gears. This species is of no commercial value and is discarded when caught (Walker and Gason 2007).
Where the species is taken as bycatch, a concern is the demonstrated low post-release survivorship of trawl caught stingarees (Campbell et al. 2018), and the fact that urolophids frequently abort pups upon capture and handling; even if gravid females survived capture, their reproductive output can be lost (White et al. 2001, Trinnie et al. 2009, Adams et al. 2018).
The species may also be subject to localised habitat loss and degradation due to increased levels of recreational water use and development in shallow embayments around southern Australia.

Citation

Kyne, P.M., Last, P.R. & Marshall, L.J. 2019. Urolophus gigasThe IUCN Red List of Threatened Species 2019: e.T60094A68649513. https://dx.doi.org/10.2305/IUCN.UK.2019-1.RLTS.T60094A68649513.en. Downloaded on 26 March 2021.

Reproduction

Viviparous, probably with trophodermic nutrition. Up to 13 pups per litter.

Diet

Diet unrecorded.

Behavior

The spotted stingaree hides in reef crevices, under ledges, and in seaweeds to avoid detection. Little else is known of its behavior.

Reaction to divers

Easy to approach. Generally remains motionless unless closely disturbed.

Diving logistics

The spotted stingaree is seen infrequently at numerous dive sites in the Great Australian Bight.

I encountered this species in Albany, WA, but this is at the extreme western edge of the species known range so they may be more common further south and east.

Searching under ledges and seaweed, and examining reef crevices while diving in mixed terrain is probably the best approach.

Similar species

Circular Stingaree Distinguished in the field by subtle differences in dorsal patterning; most notably the central dark circle on mid back that is ringed in pale blotches and has a pale blotch in its centre.