Ningaloo Maskray: Neotrygon ningalooensis

Family: Dasyatidae

Common names

Ningaloo Maskray.

Binomial

Neotrygon ningalooensis.

Synonyms

None.

Identification

A small stingray with a kite-shaped disc that is slightly wider than long. Disc width ~1.1 x length. Short, bluntly angular to somewhat rounded snout, without an extended tip. Weakly undulate anterior margins of pectoral fins. Pectoral fin apices broadly rounded. Large pelvic fins with narrowly rounded apices. Large, greatly protruding eyes. Mouth small with prominent labial furrows and folds and two very long oral papillae. Fairly narrow, skirt-shaped nasal curtain with an undulate fringed posterior margin.
Skin lacking denticles, but with 4-5 small thorns on midline. No thorns on tail. Broad based tail, depressed at base, tapering gently to caudal sting, then thin to tip. Tail short ~1.1 x disc width. Long, low ventral finfold. Short, but prominent dorsal finfold posterior to sting. Two tail stings usually present.

Colour

Dorsum yellowish-brown with large pale blotches, small orange speckles, and small pale blue spots. Distinct or sometimes faint dark ‘mask’ across eyes. Two large dark blotches or a short dark band shoulders. Ventrum white with dark margins. Anterior half of tail and dorsal finfold speckled. Tail beyond ventral finfold banded to tip, often mostly black with thin white rings and one or two long white sections close to tip.

Size

Maximum disc width ~30cm.

Ningaloo Maskray, Neotrygon ningalooensis. Bundegi Beach, Exmouth Gulf, Western Australia, Indian Ocean.

Conservation Status

DATA DEFICIENT

Although the Ningaloo Maskray has not yet been assessed by the IUCN, its status is likely similar to the sympatric Painted Maskray (Neotrygon leylandi) which is assessed as ‘Least Concern’. However, the Ningaloo Maskray has an even smaller range and appears to be confined to very shallow water less than 5m deep. The two areas with highest (known) population density are Bundegi Beach and Shark Bay, which are both protected from commercial fishing, but Ningaloo Maskrays may be impacted by recreational shore fishing.

Habitat

Tropical seas. On sandy substrates, coral rubble, and seaweed. Confined to very shallow water usually shallower than 5m deep.

Distribution

Eastern Indian Ocean. The Ningaloo maskray inhabits a small stretch of coastline in Western Australia from Shark Bay northward to Exmouth Gulf.

Reproduction

Matrotrophic aplacental viviparity. Litter size unknown.

Diet

Diet unknown, but probably small benthic invertebrates.

Behavior

During the day, the Ningaloo Maskray remains very close to shore in Exmouth Gulf, resting in low seaweed beds where it is expertly camouflaged.

Reaction to divers

Skittish, but fairly easy to approach on snorkel. Generally bolts after a few seconds once engaged.

Diving logistics

Ningaloo Maskrays are easy to find by snorkeling off of the beaches on the western edge of the Exmouth Gulf. Bundegi Beach in particular is a good spot to see this species. Search in the shallow seaweed beds a few meters from shore where they hide in plain sight during the day.