Apistogrammas are identified by the use of "A numbers"in a similar fashion to the "L number" system used to identify loricariids. Apistogramma brevis is identified as A168. Additionally, apistos are also grouped into type families and this species is the species type of the brevis group.

Unlike some apistogramma species, a. brevis occurs only in a relatively small range and has not been found outside this.

personata complex gibbiceps group…

This is the type species of the genus Aequidens and has the widest distribution of any member species. It exists in various colour forms depending on locality with variants from Ecuador and Peru being particularly sought after since they develop striking red (Ecuador) or orange (Peru) colouration on the lower part of the jaw, head and anterior portion of the belly whereas those from Brazil tend to have an overall grey/blue/green colouration, for example.

Despite its type status it's long…

In the Amazon region it is only specimens larger than around 160 cm and werighing in excess of 50 kg that are referred to as ‘Piraíba’ with the name ‘filhote’ normally applied to smaller individuals. Other vernacular names include ‘Salton catfish’, ‘Kumakuma’; and ‘tiger antenna catfish’; with members of the genus often referred to collectively as ‘goliath catfishes’.

This species, which may also be referred to by the alternative vernacular names 'spiny catfish', 'painted talking catfish' or 'chocolate raphael', isn't particularly common in the trade and most often exported only as bycatch among shipments of Platydoras armatulus. It appears very similar to the congener A. spinosissimus with the most useful external distinguishing character being the presence of pale blotches on the dorsal surface, between the dorsal and caud…

The genus Brachychalcinus currently contains four other species: B. copei (Steindachner 1882) from the rio Madeira and rio Solimões; B. nummus Böhlke 1958 from the Upper Amazon region in Colombia, Ecuador and Peru; B. parnaibae Reis 1989 from the rio Parnaíba basin, and B. retrospina Boulenger 1892 from the Rio Paraguay system.

The group is often referred to collectively as ‘silver dollar tetras’ and tho…

A. bimaculatus is not a popular aquarium fish but is available on occasion exception, most often as a contaminant among shipments of other species.

It’s identity is also in question to an extent with the name currently applied to what is considered to represent a species complex comprising at least four taxa.

For aquarists perhaps more useful are the subtle differences in colour pattern with P. simulans differing from both P. innesi and P. axelrodi in possessing a greener (vs. bluer) lateral stripe which covers more (vs. less) of the eye/head and extends to the caudal-fin base (vs. terminating anterior to caudal-fin base), a lesser (vs. greater) amount of relatively duller (vs. brighter) red pigmentation on the flanks.

The taxonomic history of all three species is complicated with earlier authors such as Géry (1960, 1977) ten…

At least two colour forms have been traded, one of which is more intensely-coloured and has been referred to as H. sweglesi ‘red’ or ‘rubra’. The bright red pigmentation is retained in long-term captive specimens, suggesting that it is not considered to be an artefact of diet, but we suspect it might reflect conditions at the collection locality with the reddest fish putatively inhabiting blackwater and plainer forms clearwater environments. Zarske (2014) found the two forms to be identical in terms of morphology an…

A beautiful species that's not often seen for sale in the hobby, and is usually a little more expensive than other tetras when available. This is mainly due to the wild caught nature of most specimens entering the trade. It can be a little delicate when initially imported, and is sensitive to deteriorating water conditions in general. As a result, it's not a good choice for the beginner, and should only be added to well-matured tanks.

As with the closely related Hemigrammus, the ta…

Endemic to the Río Meta, a major tributary of the Río Orinoco in eastern Colombia and western Venezuela. It is known from several tributaries within the upper basin including the ríos Humea, Ocoa, Guatiquía (including its two branches the ríos Negrito and Guayuriba), Manacacias, and Metica (the name given to the upper Río Meta above its confluence with the Río Humea). It appears to be absent from the lower Meta and has not been recorded in Venezuela.