Cave catfish  (Clarias cavernicola)

The cave catfish is classified as Critically Endangered (CR) on the IUCN Red List (1).

The cave catfish (Clarias cavernicola) is a freshwater, cave-dwelling fish (2). This unusual fish lacks pigment and appears a pinkish white colour (3). It has an extended eel-like body, with long dorsal and anal fins (4). The head has a rectangular shape and the rounded snout (2) carries four pairs of thread-like barbels (5). On the upper surface of the head the eyes are either entirely absent or extremely small and covered with skin (2). The Latin species name, cavernicola, means 'cave dwelling'.

The cave catfish is found only in the Aigamas Cave in Namibia (2).

The cave catfish inhabits open, clear water over rocky shelves (6).

This cave-dwelling fish feeds opportunistically on particles that fall into the lake, from bat droppings to animal carcasses and insects (2). Due to the lack of light in the cave where it lives, the cave catfish is sightless, detecting prey by means of taste buds and other senses on the barbels (4). There is currently no data available on its breeding habits (3).

The cave catfish is found only within a single cave in Namibia and is therefore at inherent risk of extinction due to any chance event. The main threat to the species comes from the depletion of ground water within the cave, and the exploitation of aquifer water may pose the most serious threat in the long-term (3).

The protection of the Aigamas Cave is vital in the conservation of this species, and the present owner is sympathetic to the sensitivity of the cave, only allowing access or collection of the cave catfish with a Nature Conservation Permit (3). Twenty captive specimens were held in the National Zoological Gardens' aquarium in Pretoria for several years (3), but no longer persist (7). There is also a move to provide legislative protection for this rare and unique fish (3).

View information on this species at the UNEP World Conservation Monitoring Centre.