General

''Austroglanis barnardi'' is an endangered species of catfish (order Siluriformes). It is one of three members of the family Austroglanididae. It is also known as the spotted rock-catfish or Barnard's rock-catfish.

Biology

Not much is known about the biology of ''A. barnardi'' because of the discovery being so recent. It has a 12-year

generation time In population biology and demography, generation time is the average time between two consecutive generations in the lineages of a population. In human populations, generation time typically ranges from 22 to 33 years. Historians sometimes use this ...

but nothing more is known about reproduction within the species. It feeds on aquatic insects, benthic invertebrates and other small fishes.

Habitat

This species is endemic to South Africa and is found only in freshwater bodies of subtropical climate. It has only been recorded from the Thee, Noordhoeks and Hex Rivers, which are all small tributaries of the Clanwilliam Olifants River System in the Western Cape, South Africa. It is extremely uncommon in these two streams it inhabits. ''A. barnardi'' inhabits riffles among loosely bedded rocks and coarse sand. Its preferred water depth is between 10-60 centimeters. Other species that occur in this area include ''Pseudobarbus phlegethon'', ''Barbus calidus'', and ''Austroglanis gilli''.

Physical Description

These fish reach a length of about 8 centimeters (3 in). Its head is flattened with a broad snout with its eyes located on the top of the head. The mouth is located on the underside of the head along with fleshy lips. It has three pairs of barbels. It has short, round fins accompanied by weak, curved spines on the pectoral and dorsal fins. Their color is golden-brown with dark brown blotches.

Threats

''A. barnardi'' is threatened by various forms of

habitat destruction Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...

such as stream channelization, water abstraction, and sedimentation, all of which reduce the incidence of their obligate riffle habitat. Portions of their river habitat are adjacent to agricultural fields and orchards, so it is likely that pesticides and insecticides affect populations. It has been threatened by the introduction of invasive species such as tilapia, smallmouth bass and the bluegill sunfish.

Conservation

Biologists have recently discussed many conservation methods. In 2013, an alien fish barrier was constructed across a section of the Noordhoeks River to keep ''Micropterus'' species from moving upstream from this section of river. Additionally, invasive spotted bass were removed mechanically from sections of the Thee river mechanically between 2010 and 2014. No known populations are currently within the boundaries of any provincial nature reserves.

References

Austroglanididae Freshwater fish of South Africa {{catfish-stub