Pseudobarbus asper 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Actinopterygii Cypriniformes Cyprinidae

Scientific Name: Pseudobarbus asper (Boulenger, 1911)
Common Name(s):
English Smallscale Redfin
Barbus asper Boulenger, 1911

Assessment Information [top]

Red List Category & Criteria: Endangered B2ab(ii,iii,v) ver 3.1
Year Published: 2007
Date Assessed: 2007-03-01
Assessor(s): Swartz, E. & Impson, D.
Reviewer(s): Snoeks, J. (Freshwater Fish Red List Authority) & Darwall, W. (Freshwater Biodiversity Assessment Programme)
This species has recently (since 1998) experienced a major reduction in population size in the Groot River of the Gamtoos River system due to the presence of Clarias gariepinus (estimated global population decline of more than 30% since 1998 (E. Swartz, pers. comm.)). P. asper also occurs widely in the Gourits River system, however the future threat from Clarias gariepinus in this system is serious and the potential loss of habitat to this alien can cause a very rapid decline. The Gourits will probably experience the same rate and severity of decline as seen in the Groot River system once Clarias gariepinus establishes (there is a high likelihood of this happening). Area of occupancy (AOO) is estimated at less than 500 km², with only two locations known, defined as the Gourits and Gamtoos River systems; there are no known areas in the Gamtoos and Gourits River systems where barriers protect this species against invasion by Clarias gariepinus. Habitat loss is ongoing. The species qualifies for EN under criterion B2ab(ii,iii,v). There is no information about overall number of mature individuals, however the current population size is expected to be in the thousands.
Previously published Red List assessments:

Geographic Range [top]

Range Description:Prefers mainstream areas of the Gamtoos and Gourits River systems but also occurs in lower reaches of tributary streams in the latter river system (Skelton 2001, Swartz 2005).
Countries occurrence:
South Africa (Eastern Cape Province, Western Cape)
Additional data:
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:This species has recently (since 1998) experienced a major reduction in population size in the Groot River of the Gamtoos River system due to Clarias gariepinus. This species also occurs widely in the Gourits River system.
Current Population Trend:Decreasing
Additional data:

Habitat and Ecology [top]

Habitat and Ecology:The species prefers mainstream areas with high mineral content that may be slightly turbid.

Threats [top]

Major Threat(s): Mainstream areas are under threat due to increasing impacts downstream of agricultural activities and excessive water extraction. However, the main threat to this species seems to be Clarias gariepinus. This alien has caused the recent rapid decline of this species in the Gamtoos River system (since 1998).

Conservation Actions [top]

Conservation Actions: No conservation actions are in place for this species, mainly because it has not been perceived as threatened in the past. However, the rapid loss of range to Clarias gariepinus in the Gamtoos River system is of concern and there are already reports of this alien species being placed in farm dams in the Gourits River system. Urgent conservation actions are need to prevent the introduction and spread of this alien fish species.

Citation: Swartz, E. & Impson, D. 2007. Pseudobarbus asper. The IUCN Red List of Threatened Species 2007: e.T18477A8330018. . Downloaded on 25 June 2018.
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