Fluvitrygon oxyrhyncha 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Chondrichthyes Myliobatiformes Dasyatidae

Scientific Name: Fluvitrygon oxyrhyncha (Sauvage, 1878)
Common Name(s):
English Longnose Marbled Whipray, Longnose Marbled Stingray, Marbled Freshwater Stingray
Himantura krempfi (Chabanaud, 1923)
Himantura oxyrhyncha (Sauvage, 1878)
Himantura oxyrhynchus (Sauvage, 1878)
Trygon oxyrhynchus Sauvage, 1878
Taxonomic Source(s): Eschmeyer, W.N., Fricke, R. and Van der Laan, R. (eds). 2016. Catalog of Fishes: genera, species, references. Updated 29 September 2016. Available at: (Accessed: 29 September 2016).
Taxonomic Notes: Last et al. (2016) placed Himantura kittipongi, H. oxyrhyncha, and H. signifer within their newly described genus Fluvitrygon.

This species was submitted to The IUCN Red List in 2000 as H. oxyrhyncha, but it was noted as H. oxyrhynchus in Eschmeyer and on FishBase. L. Compagno comments "as a noun in apposition to the generic name, the original spelling oxyrhynchus can be retained". But, more recent correspondence from the IUCN SSC Shark Specialist Group (SSG) states that the species should be oxyrhyncha and not oxyrhynchus (Pete Kyne in litt. 2004). M. Kottelat (pers. comm. 2011) commented that oxyrhynchus is the correct spelling, which conforms to the International Commission on Zoological Nomenclature in his opinion, based on rules for the formation of complex nouns.

W. White (pers. comm. 2011; SSG) expressed the opinion that, 'given the genus name this [the -a ending] makes sense unless it was named as a noun in apposition which it mustn’t have been.'

Assessment Information [top]

Red List Category & Criteria: Endangered B1ab(iii) ver 3.1
Year Published: 2016
Date Assessed: 2005-10-03
Needs updating
Assessor(s): Compagno, L.J.V.
Reviewer(s): Musick, J.A. & Fowler, S.L.
This is an amended version of the 2005 assessment to accommodate the change in genus name from Himantura to Fluvitrygon. The assessment is based on the information published in the 2005 shark status survey (Fowler et al. 2005).

The Longnose Marbled Whipray (Fluvitrygon 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:

Geographic Range [top]

Range Description:This species occurs in freshwater 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
Additional data:
Range Map:Click here to open the map viewer and explore range.

Population [top]

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.

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. 2016. Fluvitrygon oxyrhyncha. The IUCN Red List of Threatened Species 2016: e.T44185A104180982. . Downloaded on 23 May 2018.
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