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.

Known from minor rivers in the coastal states of São Paolo, Paraná, and Santa Catarina, southern Brazil, plus some tributaries of the rio Paraná basin in Paraguay.

Type locality is ‘Paranaguá, 25°32’S, 48°36’W, Paraná, Brazil’.

S. pappaterra is relatively rare in the ornamental trade and much sought after by enthusiasts.

It is easily distinguished from all known congeners by presence of a series of prominent black blotches beneath the dorsal-fin, plus a well-defined dark band extending along the side of the body. In recent genetic analyses its genetic distinctness was strongly supported, with S. jurupari and S. leucosticta its closest relatives.

Occurs naturally in Brazil, Paraguay, Uruguay and Argentina with feral populations in Australia, New Zealand, Ethiopia and Malawi which were purportedly introduced for purposes of mosquito control but are now considered invasive.

Following Lucinda (2008) its natural range comprises the Lagoa dos Patos system, lower rio Uruguai, rio Tramandaí, and rio Mampituba in Rio Grande do Sul st…

This species has been traded as ‘six-eyed tetra’ in reference to its colour pattern comprising two dark spots on each flank plus the eye.

Based on the extensive review of the genus by Lucena and Malabarba (2010), in which nine new species were described, P. tegatus can be told apart from congeners by the following combination of characters: lateral line incomplete with 8-13 perforated scales; laterally elongate humera…

A paternal ‘lip brooder’ which has been bred in aquaria.

Post-spawning the male carries the eggs attached to his labial barbels for a period of 12-14 days after which the fry hatch with a large yolk sac attached, this being absorbed over the next 48 hours or so.

During incubation the behaviour of the male i…

Type locality is given simply as ‘Amazon River, Brazil’ and according to current thinking this species has a huge natural range encompassing the Amazon River system in Brazil and Peru plus the Paraná-Paraguay drainage in southern Brazil and Paraguay and rio São Francisco basin in southern Brazil.

Specimens in our images were collected fro…

C. aurofrenatus is currently understood to occur throughout much of the Río Paraguay-Paraná system in Paraguay, and has also been recorded in Argentina and Bolivia.

It was described from Paraguay with type locality given as ‘Aguada near Arroyo Trementina’. The latter is stated to be a tributary of the ‘Rio Aquido Canigi’.

An obligate piscivore capable of consuming surprisingly surprisingly large prey.

Newly-imported specimens may refuse to accept anything but live fishes although most can be weaned onto dead alternatives once they recognise them as edible, and some even learn to accept dried foods-

Like the vast majority of predatory fishes this specie…

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…