Pterophyllum leopoldi can be differentiated from other members of the genus by the presence of up to 11 vertical stripes on the body, though often only the 3 largest, boldest stripes can be seen. This species also shows a dark patch over the operculum.

In adult specimens, a red/maroon hue over the back and fins is characteristic of the species, leading some to believe the most colourful natural form Angelfish.

The name-sake roman nose possessed by the fish is also very distinctive and used as a meristic feature.

Apistogramma commbrae and other members of the commbrae complex can be distinguished from congeners by the conspicuous double caudal peduncle spot. This species may also be polymorphic, with some males exhibiting red and blue markings on the cheeks and a yellow gular region.

Prior to the description of C. gibberosa in 2003 the genus Cyphotilapia was considered monotypic for almost a century. Members are separated from other cichlid taxa inhabiting Lake Tanganyika by possession of a hump on the forehead and broad vertical bands on the body, although the latter tend not to be visible in large males.

Known only from affluents within the upper rio Tocantins basin draining into the enormous Serra da Mesa hydroelectric reservoir in Goiás state, Brazil. It has been collected from the rios Maranhão, das Almas, Traíras, and Palmerinha/Palmeira(?).

Type locality is ‘Brazil, Goiás, Rio Tocantins basin, Rio das Almas, tributary of left margin of Rio Maranhão, 14˚37′51.2″S, 49˚1′56.6″W’.

Retroculus spp. are unsuitable for the standard community aquarium, and should be maintained in a set-up designed to resemble a flowing river. The substrate should be composed of soft sand mixed with small pebbles if the aim is to breed the fish (see ‘Reproduction’). Rocks, boulders, roots, branches, and aquatic plants can also be added, although the la…

Based on current knowledge, it thus remains impossible to deduce whether the group of putative species currently comprising S. jurupari, S. mapiritensis, and S. rhynchitis, plus populations from Amapá and the upper Negro/upper Orinoco region, represent distinct taxa or a single meta-population which can be referred to as S. jurupari sensu lato. Here on SF we include the named species separately, since they continue to be considered valid.

Despite its extensive natural distribution S. lilith is uncommon in the ornamental trade, where it is sometimes referred to as ‘one-spotted demon fish’ or ‘one spot eartheater’.

It can be distinguished from other members of the genus by possessing a single dark blotch on the flank and a prominent ocellus at the caudal-fin base. Among the named species it is most similar to S. daemon, but that species possesses two blotches on the flank.