The carnivores – Pseudacanthicus andScobinancistrus
Author: Darren Stevens
First published in Aquarium World May 2010
Although most plecos are herbivores or omnivores, there are a few mainly carnivorous plecos, including two spectacular beauties – the leopard cactus pleco and the goldie pleco. These plecos grow large and can be aggressive – particularly as adults, and as such are only suitable for large tanks with plenty of cover and line of sight barriers. Feed your carnivorous plecos on a varied protein-rich diet, along with a few veggies. I feed mine on carnivore pellets, trout pellets, shrimps, fish, frozen mussels, bloodworms, algae wafers and courgettes.
Pseudacanthicus means ‘false thorns’ in reference to the numerous thorn-like spikes that adorn the body, and give rise to the common name of cactus pleco. There are seven scientifically described cactus plecos and several awaiting a scientific name. Cactus plecos are generally found in deeper water in lowland rivers in north-eastern Brazil, although the odd species is found in the Guyanas. Most species grow to about 25-30cm, although there are notable exceptions such as the P. hystrix which grows to at least 80cm. Many cactus plecos have limited ranges and are therefore susceptible to overfishing. For this reason the export of many Brazilian species has been banned by IBAMA, Brazil’s environmental protection agency. However the leopard cactus pleco is widespread and approved for export.
The leopard cactus pleco is a large (to 24 cm standard length, SL) pale orange-brown pleco covered with irregular large black spots separated by a thin margin, giving a honeycombed appearance. The dorsal (top) fin and caudal (tail) fin are covered with varying amounts of orange. There are four very similar forms (L114, L427, 'L600', LDA07) which may represent two or more species or one widespread variable species. Most leopard cactus plecos in the hobby are apparently Demini leopard cactus plecos (P. cf. leopardus, L114) from the Rio Demini in Brazil. True leopard cactus plecos (P. leopardus, 'L600') come from waterways in the vicinity of the Brazil/Guyana border, and they grow a little larger (to 35 cm TL) than L114. They also differ slightly in colour, body form, and apparently the number of teeth. Both forms are suited to larger tanks with pH’s of 5.6–7.0 and temperatures of 24–28oC. Demini leopard cactus plecos (L114) have been bred twice in New Zealand and several times overseas.
Scobinancistrus are closely related to the wood-eating Panaques, and their smaller Panaqolus relies, and some researchers consider they should be placed in a Panaque sub-group. They have a few (about 6-8) long narrow spoon-shaped teeth on each jaw, while Panaques and Panaqolus have several shorter, broader spoon-shaped teeth. Their large ‘buck-teeth’ are thought to be for eating molluscs (snails and other shellfish), and they are effective snail eaters in aquariums. Scobinancistrus are found in clear waterways in north-eastern Brazil (the rios (rivers) Xingu, Tapajos, Tocantins, Jamanxim, and Cupari), where they are captured by divers with air supplies (sometimes in over 20 metres depth). There are two scientifically described Scobinancistrus species: the golden cloud pleco, S. pariolispos and the goldie or sunshine pleco, S. aureatus, and another couple awaiting a scientific name. Golden cloud plecos are black with white spots and are very rare in New Zealand, while goldie plecos are regularly imported.
Goldie or Sunshine pleco (Scobinancistrus aureatus, L014)
Goldie or sunshine plecos are a large (to 30 cm SL) striking black bodied pleco covered with fine white to yellowish spots. In juveniles, the fins, tail, and suckermouth are yellow-orange. As they grow the spots become finer, more numerous, and spread over the fins; and the yellow-orange colour on the fins and tail becomes more yellowish and fades to the tips. Goldie plecos are relatively peaceful but will hold their own once established. They can be aggressive towards others goldies, particularly if there is not sufficient space for territories, and may inflict painful injuries with their teeth. They originate from the Rio Xingu in Brazil, where they live alongside zebra plecos (Hypancistrus zebra) and gold nuggets (Baryancistrus xanthellus L018, L085). They are suited to larger tanks with pH’s of 5.8–7.2 and temperatures of 25–29oC. Goldie plecos have been bred occasionally overseas.
There are other mainly carnivorous plecos that are occasionally seen in New Zealand, including the coffee and cream cactus pleco (Pseudacanthicus spinosus, L160), scarlet pleco (Pseudacanthicus pirarara, L025), galaxy or vampire pleco (Leporacanthicus galaxias, L007, L029), and the golden vampire pleco (L. heterodon, L172).
I would like to thank Firenzenz and Krazy Geoff for their comments and improvements on earlier versions of this article.
Planet catfish (www.planetcatfish.com)
Jonathan Armbrusters Loricariidae website
(http://www.auburn.edu/academic/science math/res_area/ loricariid/fish_key/lorhome/index.html)
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Evers, H-G.; Seidel, I. (2005). Baensch Catfish Atlas Vol 1. Mergus, Germany. 943 p.
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