Australian Bluespotted Maskray: Neotrygon australiae

Family: Dasyatidae
Common name(s)

Australian Bluespotted Maskray.

Identification

A small stingray with a kite-shaped disc that is wider than long; disc width approximately 1.2-1.3 x length. Snout very short, and bluntly angular. Tip of snout not extended. Anterior margins of disc weakly convex. Pectoral fin apices angular. Pelvic fins large; apices narrowly rounded.
Eyes large and protruding. Snout length 0.8-1.2 x combined eye and spiracle length.
Mouth small, containing 2 large central oral papillae. Prominent labial furrows and folds around mouth. Nasal curtain narrow and skirt-shaped; posterior margin undulate and heavily fringed. Nostrils thin.
Denticles on disc absent except for a varying row of small thorns extending from nape to level of cloaca. Tail broad and depressed at base, tapering gently to caudal sting, then thin but firm to tip. No prickly denticles on tail. Tail length (when intact) up to 1.5 x disc width. Ventral finfold long and low. Dorsal finfold very short; length approximately 4-6.6 x shorter than ventral fold. 1-2 tail stings usually present.

Colour

Dorsum Yellow-brown with a distinct but dusky brown band across eyes, and numerous eye-sized blue spots, often with pale centres. Spots sparser and smaller towards disc margin. Ventrum white with a greyish submarginal band. Tail beyond caudal fades to black with irregular white bands. Caudal finfolds mostly black.

Size

Maximum disc width 38cm. Disc width at birth unknown.

Habitat

Tropical seas. On sandy substrates, often adjacent to reefs. From 23-91m.

Distribution

In Australia from Shark Bay in Western Australia to Cape Tribulation, northward to southern Indonesia; Bali, Nusa Tenggara Archipelago, and southern West Papua, and into southern PNG.
Identical looking bluespotted maskrays from the east coast of Australia likely represent an overlooked range extension of this species.

Conservation Status

NOT EVALUATED

Australian bluespotted maskrays are part of a recently (2016) split complex of rays that were previously grouped as Dasyatis kuhlii. This member of the Kuhlii complex has not yet been assessed by the IUCN.

Citation

Last, P.R., White, W.T. and B. Séret, 2016. Taxonomic status of maskrays of the Neotrygon kuhlii species complex (Myliobatoidei: Dasyatidae) with the description of three new species from the Indo-West Pacific. Zootaxa 4083(4):533-561. (Ref. 116741)

Reproduction

Matrotrophic aplacental viviparity. Litter size unknown.

Diet

Diet unknown.

Behavior

Sedentary. Behavior poorly known.

Reaction to divers

Shy and difficult to approach unless extremely accustomed to divers.

Diving logistics

Although the Australian bluespotted maskray is probably quite common in northern Australia, conditions in the Northern Territory are far from ideal for scuba diving due to high levels of run off from numerous rivers, and because of the danger of encountering saltwater crocodiles. Consequently, most Australian encounters occur in northern WA. Exmouth is probably the best area to look for this ray within Australia.

In Indonesia, diving conditions are much more favourable. Australian bluespotted maskrays are seen at hundreds of dive sites from Bali eastwards to PNG. One of many sights to see this ray in Indonesia is at Nusa Penida; a popular diving island on the south coast of Bali.

Similar species

Oriental Bluespotted Maskray A very similar ray. Distinguishable by blue spots that concentrated on the pectoral fins and less dense on the medial strip of the disc. Plus, more northerly (but likely overlapping) range.