This species is not normally aggressive towards conspecifics with juveniles in particular exhibiting a marked schooling instinct.

Older individuals tend to be more solitary but still group together from time-to-time, and it’s best maintained in numbers of four or more.

One important point to note is that acestrorhynchids are can…

The genus Ageneiosus was at one point classified in the family Ageneiosidae alongside the genus Tetranematichthys, but this was not accepted by all authors. The grouping remains poorly-studied with the last major revision having been conducted by Watson (1990) in his unpublished dissertation, in which A. inermis was included under the currently synonymous name A. brevifilis. It can be separated from the majority of the genus (except A. marmoratus) by possession of a truncate caudal fin, and from…

This species is relatively rare in the hobby but sometimes available from specialist retailers or private breeders. Though described in 1991 it was first collected much earlier and misidentified by Gosse (1976) as G. surinamensis.

It’s one of just five Geophagus species not to be included in the nominal G. surinamensis ‘group’ of closely-related species within the genus along with G. gottwaldi, G. grammepareius, G. harreri an…

One of the most enigmatic species in the hobby, this incredible little catfish must rank amongst the most stunning freshwater species known. In the late 1990s and the early part of this century you could buy one of these for as little as twenty pounds. However in 2004, the Brazilian government banned the exportation of the species amid apparent concerns over the exploitation of wild stocks. As yet, the conservation status of the fish has not been confirmed by any scientific proof with the only e…

This unidentified species possesses a highly variable colour pattern with the pale, randomly-arranged spots and blotches on the body ranging in colour from whitish to yellowish to rusty orange depending on the specimen.

It’s regularly confused with similar-looking relativ…

Collected from the rio Xingu downstream and in the vicinity of Belo Monte, Pará state, northern Brazil.

The majority of its natural habitat is likely to be severely degraded in the near future due to ongoing construction of the Belo Monte dam.

Prior to description in 2011 this species was traded under the DATZ code numbers L018, L085, L077 and ‘Das Aquarium’ code LDA060, while a very similar-looking fish from the lower rio Xingu which has been assigned the code L081 may also represent a form of B. xanthellus but is not mentioned in the description paper.

B. xanthellus can be distinguished from congeners by a combination of the following…

Prior to description this species was traded under the DATZ code L047 or the alternative vernacular name ‘magnum pleco’. It can be distinguished from congeners by a combination of the following characters: presence of a broad, light-coloured (usually yellowish) distal band on the dorsal and caudal fins throughout life, slightly reduced in adults. The only other member of the genus to possess such bands is B. xanthellus but in that species they are reduced to small markings at the fin tips in adults, and the body is covered in pale, normally yellowish, spots.

It remains unconfirmed as to whether this fish represents a colour form of B. xanthellus or not since its DATZ code number of L081 is not referred to in the description paper whereas all other codes for ‘gold nugget’ plecos, i.e., L018, L085, L177 plus the ‘Das Aquarium’ code LDA060 are mentioned.

In addition, one of the specimens in our images was apparently collected at São Félix do Xingu which is significantl…

A somewhat odd-looking species with a distinctive wide head and overall flattened profile. Unfortunately this fish is not the easiest fish to keep alive in the aquarium since it requires rather specialised conditions and is often in poor condition post-import.