Giant freshwater stingray

This article is about the giant freshwater stingray from Asia. For the giant freshwater stingray from South America, see short-tailed river stingray.

Giant freshwater stingray
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Subclass: Elasmobranchii
Order: Myliobatiformes
Family: Dasyatidae
Genus: Urogymnus
Species:
U. polylepis
Binomial name
Urogymnus polylepis
(Bleeker, 1852)
Geographic range (excludes populations not confirmed as extant and/or conspecific)[1]
Synonyms
  • Himantura chaophraya Monkolprasit & Roberts, 1990
  • Trygon polylepis Bleeker, 1852
  • Himantura polylepsis (Bleeker, 1852)

The giant freshwater stingray (Urogymnus polylepis, also widely known by the junior synonym Himantura chaophraya) is a species of stingray in the family Dasyatidae. It is found in large rivers and estuaries in Southeast Asia and Borneo, though historically it may have been more widely distributed in South and Southeast Asia. The widest freshwater fish and the largest stingray in the world, this species grows up to 2.2 m (7.2 ft) across and can reach up to 300 kg (660 lb) in weight. It has a relatively thin, oval pectoral fin disc that is widest anteriorly, and a sharply pointed snout with a protruding tip. Its tail is thin and whip-like, and lacks fin folds. This species is uniformly grayish brown above and white below; the underside of the pectoral and pelvic fins bear distinctive wide, dark bands on their posterior margins.

Bottom-dwelling in nature, the giant freshwater stingray inhabits sandy or muddy areas and preys on small fishes and invertebrates. Females give live birth to litters of one to four pups, which are sustained to term by maternally produced histotroph ("uterine milk"). This species faces heavy fishing pressure for meat, recreation, and aquarium display, as well as extensive habitat degradation and fragmentation. These forces have resulted in substantial population declines in at least central Thailand and Cambodia. As a result, the International Union for Conservation of Nature (IUCN) has assessed the giant freshwater stingray as Endangered.

  1. ^ a b Grant, I.; Rigby, C.L.; Bin Ali, A.; Fahmi, Haque, A.B.; Hasan, V.; Sayer, C. (2021). "Urogymnus polylepis". IUCN Red List of Threatened Species. 2021: e.T195320A104294071. doi:10.2305/IUCN.UK.2021-2.RLTS.T195320A104294071.en. Retrieved 13 November 2021.{{cite journal}}: CS1 maint: multiple names: authors list (link)