Austroglanis barnardi 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Actinopterygii Siluriformes Austroglanididae

Scientific Name: Austroglanis barnardi (Skelton, 1981)
Common Name(s):
English Barnard's Rock-catfish, Spotted Rock Catfish
Gephyroglanis barnardi Skelton, 1981
Taxonomic Notes: Formerly placed in family Bagridae, but recognized in a separate family by Mo (1991) and de Pinna (1998) (Nelson 2006).

Assessment Information [top]

Red List Category & Criteria: Endangered B1ab(ii,iii,v)+2ab(ii,iii,v) ver 3.1
Year Published: 2007
Date Assessed: 2007-03-01
Assessor(s): Swartz, E., Bills, R. & Impson, D.
Reviewer(s): Snoeks, J. (Freshwater Fish Red List Authority) & Darwall, W. (Freshwater Biodiversity Assessment Unit)
Locations have been identified as the three surviving populations. Bills (1999) established the lower limits and in some cases upper limits of this species in the three tributary streams where they currently still occur and also showed that they still occur in the mainstream Olifants River near the Heks tributary. Since his last assessment, there has been a reduction in range in the Noordhoeks River due to changes in the extent of water extraction. The Noordhoeks has been established as the most important population for conservation, since it has the best habitat and has the largest population. The occurrence of this species in the mainstream Olifants River is uncertain, since the habitat where they occurred has dried up several times since 1999 and may only be colonized from the Heks River during times of favourable flow when the cobble habitat has been flushed of sediments. These two reductions in range may account for a large loss of the species' extent of occurrence (EOO). However, criterion A is not relevant, since the loss of habitat probably does not result in a reduction of at least 30%. The species has an EOO of less than 5,000 km², an area of occurrence (AOO) of less than 10 km², is fragmented, and only three populations remain (less than five localities) with continuing decline in AOO, habitat and number of mature individuals. However, despite being fragmented, the three populations are probably each large enough to survive on their own without the need for immigration. It therefore qualifies under Endangered B1ab(ii,iii,v)+2ab(ii,iii,v) and as Critically Endangered under only B2b(ii,iii,v) (i.e., insufficient criteria for CR). The overall assessment for is therefore Endangered under criterion B. There are no reliable population estimates at this stage, but provisional indications are that it would not qualify under criteria C or D and no quantitative analysis has been carried out to consider criterion E.
Previously published Red List assessments:

Geographic Range [top]

Range Description:This species is endemic to three tributary streams of the Olifants branch of the Olifants River system that drains the Cederberg Mountains (Bills 1999). They have been recorded in recent times in the mainstream of the mainstream of the Olifants River, but unsustainable water extraction has caused these areas to dry up several times in the last few years, suggesting that this area is recolonized from the Heks population.
Countries occurrence:
South Africa (Western Cape)
Additional data:
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:Although the range of this species is reasonably well understood, information about population trends is lacking. There has probably been a loss of mainstream habitats in the last ten years, and the distribution range in the Noordhoeks tributary has fluctuated depending on where water extraction occurs. However, more accurate information is needed to study long-term trends.
Current Population Trend:Decreasing
Additional data:

Habitat and Ecology [top]

Habitat and Ecology:Prefers fast flowing, rocky habitats of headwater streams. They seem to be restricted to cobble zones of the lower gradient sections of tributary streams (Bills 1999).

Threats [top]

Major Threat(s): Alien invasive species have severely fragmented populations of this species in the past. Especially Micropterus dolomieu, must have caused a major reduction in population size just after their introduction in the 1940s. Unsustainable water extraction is a major threat, especially the low gradient sections of tributary streams that this species seems to prefer. All the water of all four tributary streams is being used during summer months, with the result that this species only survives above extraction points. The effect of insecticides has not been quantified, but all the tributary streams has orchards before they reach the Olifants River (Bills 1999).

Conservation Actions [top]

Conservation Actions: No conservation measures specifically designed for the recovery of this species has been established. Plans are underway to do river rehabilitation for other species elsewhere in the Cederberg Mountains, and if successful it can be attempted for tributary streams where this species occurs.

Citation: Swartz, E., Bills, R. & Impson, D. 2007. Austroglanis barnardi. The IUCN Red List of Threatened Species 2007: e.T2426A9437974. . Downloaded on 19 October 2017.
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