It looks like a banjo catfish but it's actually an akysid catfish from the Far East. Matt Clarke explains how to keep Acrochordonichthys rugosus.
Scientific name: Acrochordonichthys rugosus
Origin: A. rugosus has been collected in Java, Sumatra, Thailand and Malaysia.
Size: Around 10cm/4".
Diet: This small, predatory akysid catfish is said to feed on small balitorid loaches, such as nemacheilines, so be careful what you mix it with. They are nocturnal, so don't expect to see much movement during the day.
Habitat: These tend to live among leaves and bogwood in deep, fast-flowing sandy or rocky bottomed forest streams.
Water: They don't like being kept too warm, 20-25C/68-77F is fine. They appear to be quite adaptable to more alkaline waters, but pH 6.0-7.0 is ideal. Keep the water well oxygenated.
Aquarium: A South-east Asian riverine biotope tank with a bogwood and leaf-litter base, and plenty of water movement, is good. They can be kept in groups and leave most fish alone - if they're not snack-sized.
Breeding: Probably never bred in captivity. Females are said to be fatter and males have a narrow genital papilla in front of the anus.
Identification: Difficult to identify correctly as they undergo ontogenetic changes in morphology and colour. The importer says this fish is A. rugosus, however, these catfish vary in colour and morphology so may be one of 12 other species in the genus. Some specimens of A. chamaeleon look similar to this fish.
Similar species: The
genus includes A. chamaeleon, falcifer, guttatus, gyrinus, ischnosoma, maha-kamensis, melanogaster, obscurus, pachyderma, septentrionalis, pleurostigma and strigosus. Five of these were described in 2001, but gyrinus was only described last year. We can't tell from this picture, but A. rugosus should have one dorsal spine and three to four soft rays, plus four to six soft rays in the anal, and serrated pectorals. See Ng and Ng (2001) for more details and a dichotomous key to 11 of the 12 Acrochordonichthys.
Notes: The tuberculate skin on these fish, like that of South American banjo cats, is warty and sometimes sloughed by the fish. Two species got their names from the texture of their skin, 'rugosus', which means rough, and 'pachyderma', suggesting the skin is elephant-like.
Availability: These were imported directly from Thailand by Maidenhead Aquatics in Harlestone Heath.
Price: Surprisingly cheap at around 2.50 each.
This article was first published in the October 2004 issue of Practical Fishkeeping magazine.