Himantura oxyrhyncha 


Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Chondrichthyes Rajiformes Dasyatidae

Scientific Name: Himantura oxyrhyncha
Species Authority: (Sauvage, 1878)
Common Name(s):
English Longnose Marbled Whipray, Longnose Marbled Stingray, Marbled Freshwater Stingray
Himantura krempfi (Chabanaud, 1923)
Himantura oxyrhynchus (Sauvage, 1878)
Trygon oxyrhynchus Sauvage, 1878

Assessment Information [top]

Red List Category & Criteria: Endangered B1ab(iii) ver 3.1
Year Published: 2005
Date Assessed: 2005-10-01
Assessor(s): Compagno, L.J.V.
Reviewer(s): Musick, J.A. & Fowler, S.L. (Shark Red List Authority)
This assessment is based on the information published in the 2005 shark status survey (Fowler et al. 2005).

The Longnose Marbled Whipray (Himantura oxyrhyncha)) is a very rare species, known from only five specimens in museum collections worldwide,with three being the syntypes from Phnom Penh, Cambodia. It is known to occur from only three or four riverine systems. It is confined to tropical freshwater habitats that are under intensive threat from fisheries, pollution, logging in the catchment areas and river engineering projects and is a desirable aquarium species.
Previously published Red List assessments:
2000 Endangered (EN)
2000 Endangered (EN)

Geographic Range [top]

Range Description: This species occurs in feshwater habitats. It is known from Grand Lac and Phnom Penh, Cambodia (Mekong River), and also from Thailand in the lower Mae Nam Nan and Chao Phraya river system (Compagno and Roberts 1982, Kottelat 1985, Cook and Compagno 1994, Compagno and Cook 1995a). Photographic evidence of a specimen landed from the Mahakam River, Kalimantan (Indonesia) (P. Last pers. comm.). It may be present but unrecorded in other rivers because of its rarity. Subpopulation details are unknown. If, as seems likely, this ray is unable to transit marine habitats, each riverine population will be completely isolated.
Countries occurrence:
Cambodia; Indonesia; Thailand
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: Rare.
Current Population Trend: Unknown
Additional data:
Population severely fragmented: No

Habitat and Ecology [top]

Habitat and Ecology: This rarely recorded freshwater species is known from only five specimens in museum collections. No information is available on any of its life history parameters.
Systems: Freshwater

Use and Trade [top]

Use and Trade: aquarium use

Threats [top]

Major Threat(s): This rare ray is taken very infrequently as bycatch in freshwater teleost fisheries, which are intensive through much of its range. It is possibly also sought after for the aquarium trade, as the young of this ray are small and particularly attractive. Two of the five known museum specimens were from aquarium suppliers. Its habitat is seriously threatened by riverine pollution from agricultural chemicals, sewage and industrial waste in the river catchments, logging activities and river engineering projects (e.g. dam construction on the Chao Phraya River). Continued habitat loss and degradation are likely a major impact on the species.

Conservation Actions [top]

Conservation Actions: The Thai government started a project in the 1990s to breed this and other freshwater stingrays in captivity at Chai Nat above the dam on the Chao Phraya River to counter declines of freshwater rays in the river. A single specimen of this ray was seen in captivity there in 1993 (but this was moribund and died during our visit). We later (1996) learned that the project had been put on hold, at least temporarily.

Citation: Compagno, L.J.V. 2005. Himantura oxyrhyncha. The IUCN Red List of Threatened Species 2005: e.T44185A10858162. . Downloaded on 30 May 2016.
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