Oriental Bluespotted Maskray.
A small stingray with a kite-shaped disc that is wider than long; disc width approximately 1.2-1.3 x length. Snout short, and bluntly rounded or obtusely angular. Tip of snout not extended. Anterior margins of disc weakly convex. Pectoral fin apices rounded to angular. Pelvic fins large; apices narrowly rounded.
Eyes large and protruding. Snout length 1-1.3 x combined eye and spiracle length.
Mouth small, containing 2 large oral papillae. Prominent labial furrows and folds around mouth. Nasal curtain narrow and skirt-shaped; posterior margin undulate and lightly fringed. Nostrils thin.
Very small denticles on mid-disc in larger adults. Variable row of small thorns on midline; more pronounced near nape. 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 6.6-7.5 x shorter than ventral fold. 1-2 tail stings usually present.
Dorsum Yellow-brown with a distinct black speckled, brown band across eyes, and numerous eye-sized blue spots, often with pale centres on disc. Blue spots mostly on pectoral fins; sparser or absent on medial strip. Ventrum white with a greyish submarginal band. Tail grey-blue anteriorly, with irregular black and white bands beyond caudal sting. Tail section before tip often solid white. Ventral finfold usually dusky.
Maximum disc width 38cm. Disc width at birth approximately 12cm.
Tropical seas. On sandy substrates, often adjacent to reefs. From inshore to less than 100m.
Southeast Asia. Found east of the Malay Peninsula from Taiwan and The Philippines southward to at least Sulawesi.
Although the oriental bluespotted stingray is not listed as occurring further east in Indonesia than Sulawesi, I have photographed what appears to be this species in Raja Ampat, West Papua.
Oriental 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.
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)
Matrotrophic aplacental viviparity. Reported pregnant females contained only a single pup.
Sedentary. Behavior poorly known.
Reaction to divers
Shy and difficult to approach unless extremely accustomed to divers.
The oriental bluespotted maskray is quite common in the Philippines and around Borneo. Virtually any shallow sandy bay will likely have one or two rays in residence.
I have also seen this species at Raja Ampat although this is outside the official range of this species.
Bluespotted Maskray A very similar ray. Distinguishable by larger size, proportionately shorter ventral finfold, and tail coloration that is browner anteriorly. Plus, more westerly (but possibly overlapping) range.
Australian Bluespotted Maskray A very similar ray. Distinguishable by blue spots that are more concentrated on the centre of the disc. Plus, more southerly (but likely overlapping) range.