Urogymnus polylepis (Bleeker, 1852)
Giant freshwater whipray
Urogymnus polylepis
photo by Jean-Francois Helias / Fishing Adventures Thailand

Family:  Dasyatidae (Stingrays), subfamily: Urogymninae
Max. size:  240 cm WD (male/unsexed); max.weight: 600 kg
Environment:  demersal; freshwater; brackish, potamodromous
Distribution:  Asia and Oceania: Mekong and Chao Phraya basins; also from eastern Borneo, New Guinea and northern Australia.
Diagnosis:  Dorsal spines (total): 0-0; Dorsal soft rays (total): 0-0. Absence of ventral and dorsal skin folds on the tail, and the broad greyish to blackish marginal band on the ventral surface of the disc. The dorsal surface of the disc is brown (Ref. 27732). Spiral valve with 21 turns; dorsal surface with uniform brown or grey coloration (Ref. 12693). Lacking caudal fin; with long whip-like tail (Ref. 43281).
Biology:  Inhabits sandy bottoms in estuaries and large rivers (Ref. 12693). Feeds on benthic invertebrates (Ref. 12693) and fishes (Ref. 32457). Ovoviviparous (Ref. 50449). Caught occasionally by demersal gillnet and longline fisheries operating in riverine and estuarine areas. Utilized for its meat and possibly its cartilage (Ref.58048). Marketed fresh, with large individuals being sold in cut pieces by the kilogram (Ref. 12693). Size reaches to about 500 cm TL. Threatened due to over harvesting and pollution (Ref. 58490).
IUCN Red List Status: Endangered (EN); Date assessed: 25 January 2021 (A2bcd) Ref. (130435)
Threat to humans:  venomous


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