Pink Whipray: Pateobatis fai

Family: Dasyatidae
Common name(s)

Pink Whipray, Tahitian Stingray.

Identification

A large stingray with a kite-shaped disc that is wider than long; disc width approximately 1.1-1.2 x length. Snout fairly short, and obtusely angular. Apical lobe (snout tip) triangular, slightly extended. Anterior margins of disc straight or weakly concave. Pectoral fin apices angular. Pelvic fins large; apices narrowly rounded.
Eyes small and slightly protruding. Snout length 1.9-2.3 x combined eye and spiracle length.
Mouth small, containing 4 oral papillae; 2 central papillae very large, lateral papillae very small. Prominent labial furrows and folds around mouth. Lower jaw slightly arched. Nasal curtain slightly skirt-shaped; posterior margin finely fringed.
A small, vague band of denticles on mid-shoulder in young animals, absent in adults exceeding 90cm DW. Tail long and narrow; sub-circular in cross-section, tapering gently to caudal sting, then filamentous to tip. Sparse small denticles on tail beyond caudal sting. Tail length (when intact) 2-2.6 x disc width. Caudal finfolds absent. One caudal sting usually present.

Colour

Dorsum grey-brown or pinkish. Pale spots anterior to eye and between eye and spiracle. Ventrum white with a broad dark margin that starts posterior to mouth level. Tail beyond caudal sting fades to black.

Size

Maximum disc width 186cm. Disc width at birth approximately 30-55cm.

Habitat

Tropical seas. On sandy substrates and reef rubble, often adjacent to reefs. From shallow bays to inner continental shelf. Intertidal to 200m.

Distribution

Indian Ocean and west/central Pacific. Recorded from South Africa and Egypt but absent (or presently unrecorded) in East Africa. Population more consistent from India, through Southeast Asia (including southern Japan) to northern Australia. Also eastward to Samoa and French Polynesia.

Conservation Status

VULNERABLE

The Pink Whipray (Pateobatis fai) is taken as a utilized bycatch of tangle/gillnet, trawl net, and dropline fisheries throughout Southeast Asia and parts of the Indian Ocean. Inshore fishing pressure is intense throughout this species’ range in Southeast Asia and in parts of the Indian Ocean. It is caught in particularly high numbers in the target fishery for rhynchobatids operating in the Arafura Sea. Although no species-specific data are available, overall catches of sharks and rays are reported to be declining, with fishermen having to travel further to sustain catch levels. Given the continuation of high levels of exploitation throughout its range in Southeast Asia where the species is commonly caught in multiple types of fisheries, along with evidence for declines in catches of rays, the level of decline (>30% over the last three generations) and exploitation can be inferred from overall declines in fish catches in the region, as well as from habitat loss.

In Australia, the Pink Whipray is considered at minimal threat throughout its wide range as there is no information to suggest that this species has declined in this area. Fisheries in northern Australia are generally well managed and the introduction of turtle exclusion devices (TEDs) have significantly reduced the bycatch of large stingrays. There are also marine protected areas in this species’ range, and this species is common in parts of the Great Barrier Reef Marine Park. This large species may have limiting life history characteristics that would make it biologically susceptible to depletion in fisheries and therefore, efforts should be made to assess and monitor mortality in fisheries and population trends throughout its range. The Pink Whipray is assessed as Vulnerable globally based on inferred levels of decline and exploitation across a large part of its range, but is considered to be Least Concern in Australia.

Citation

Manjaji Matsumoto, B.M., White, W.T., Fahmi & Gutteridge, A.N. 2016. Pateobatis faiThe IUCN Red List of Threatened Species 2016: e.T161615A104219816. https://dx.doi.org/10.2305/IUCN.UK.2016-3.RLTS.T161615A104219816.en. Downloaded on 23 February 2021.

Reproduction

Histotrophic viviparity. Litter size unknown.

Diet

Predates mainly on small fishes and prawns.

Behavior

Known to form large mating(?) aggregations of up to 25 animals during the summer months.
In Nuku Hiva, French Polynesia, on multiple occasions I have observed small groups and individual pink whiprays swimming horizontally in midwater, next to a reef face.

Reaction to divers

Shy unless accustomed to divers. Then, fairly nonchalant unless approached too closely.

Diving logistics

Pink whiprays are very common in southern Queensland, best spots to see them being Manta Bommie and Flat Rock off Brisbane, Wolf Rock off Rainbow Beach and Heron Island. Also seen at many spots in the Maldives (Nigel Marsh intel).

Nuku Hiva (the main island in the Marquesa Archipelago in French Polynesia) is also a good area for these rays. No particular dive site stands out but any spot with an accessible sandy bottom should be good. At a site called the Sentinel, near Taioha’e I encountered three pink whiprays swimming together in mid-water.

Similar species

Jenkins’ Whipray A similar ray from the Indo-West Pacific. Distinguishable by a prominent row of thorns along midline in adults.