Corantijn

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 vernacular name of this fish is derived from its appearance and behaviour, rather than a genetic association with the marine barracuda, and it's also sometimes referred to as 'pike characin' or 'spotted cachorro' with local vernacular names including 'Grand dent-chien' (French Guiana), ' Cachorrinho' or 'Ueua' (Brazil). Although most species of Acestrorhynchus appear superficially similar to one another most exhibit distinguishable external chara...

Apparently this species is polymorphic with body patterning varying significantly depending on locality. Individuals collected from black water habitats tend to be noticeably darker in overall colouration, for example, with this being particularly evident among populations from the Guiana Shield. The genus Ageneiosus was at one point classified in...

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...

C. strigata is an enduringly popular species in the aquarium hobby but is not bred on a commercial basis with all fish offered for sale collected in the wild. It can be told apart from other members of the genus by its larger adult size and dark, marbled colour pattern appearing as a series of dark and light stripes running diagonally across the body below the lateral line. This colour pattern is variable and popul...

This species can be told apart from relatives by the characteristic 'keyhole' shaped marking on each side of the body. It's one of few fishes in which the current generic name is derived from the common name popularised in the aquarium hobby with 'Cleithracara' a combination of the Greek kleithron, meaning lock, and, acará, the Guaraní word for cichlids.

This species is currently the only described member of its genus although colour pattern and morphology vary considerably across its range. You may see reference to this species being the only fish species to possess infra-red vision, but other species also possess this ability and we suspect that infra-red plays an important role in the reproductive cycle of many fishes.

This species is generally rare in the aquarium hobby though oddly appears to be one of the commoner species in Australia where it's often referred to by the vernacular name 'black-throated eartheater'. It's a member of the nominal G. surinamensis 'group' of closely-related species within the genus and can be identified by a combination of characters including: presence of dark preopercular markings; no vertical bars on the flanks even when stressed/preserved; base of filaments on the first gill arch mostly covered by a flap of skin; exposed part of bra...

This species is also referred to as 'black-anded leporinus', 'striped leporinus' and 'eight-banded leporinus'. Young specimens are often traded for aquaria without warning as to their potential size and requirements, and as a result it's fairly ubiquitous in public aquarium displays.

This is the type species of the genus, fairly ubiquitous in the aquarium trade, and represents an excellent choice for the newcomer to fishkeeping since it's less demanding than most congeners. It's sometimes referred to as 'Beckford's pencil fish' or 'brown pencilfish'. Don't worry if your fish look different when you switch on the aquarium lights after dark or in the morning as like most Nannostomus species it assumes a cryptic, vertically-barred colour pattern at ni...

There also exist a number of minor differences in colour pattern between populations. For example some Peruvian forms have yellow pigmentation on the body and fins, and those from Guyana and Suriname possess a short red stripe on vertical scale rows 6-9, above the central dark stripe on the body. Rio Negro forms have a similar red stripe but overlapping the central dark stripe and extending along most of the flank, while a form from Colombia has an elongate red stripe which is broken in two beneath the dorsal-fi...

S. leucosticta is frequently available in the ornamental trade and farmed for the purpose in several countries. It is often confused with its congener S. jurupari in aquarium literature and on websites, but is easily recognised by presence (vs. absence) of prominent white spots or vermiform markings on the sides of the head. Although the presence of white spots on the head does not distinguish it from all known Satanoperca populations (see below), it can...

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'.

Study of B. rousseauxii has revealed that sexually mature adults are found only in the western Amazon, with no mature individual ever recorded east of Manaus despite the intensive commercial fishery operating there. The total distance covered by some populations during migration from the delta was as much as 5500 km, making it the longest known in any freshwater fish species.

This rich feeding ground is exploited until the sea water returns, at which point the catfishes begin to migrate upstream in massive numbers, moving up the Amazon and its tributaries. Sexually mature individuals are not normally recorded during these events so they're thought related to feeding and dispersal rather than spawning. The fish are subject to intensive capture by commercial and artisanal fishing operations during this upstream movement.

Type locality is 'Río Yuruari, 3 kilometers east of El Callao, 7°18'N, 61°50'W, Bolivar, Venezuela', and this species is also known from the Rupununi River drianage in Guyana and the Courantyne/Corantijn system in Suriname. The Yuruari, an affluent of the Río Cuyuni, an...