This fish is normally traded as A. nigropterus or A. cf. ansorgii although neither appears to be its correct name meaning it remains unidentified at present.

A. nigropterus is a valid congener that is not in the aquarium trade with little to no export from Lake Mai-Ndombe, to which it is endemic, while A. ansorgii is a synonym of Nannopetersius ansorgii.

This species is largely unsuitable for the home aquarium given its eventual size and natural behaviour, and we know of only a handful of private aquarists with the facilities required to house it long-term.

Nonetheless juveniles and subadults are sometimes available in the trade although often misidentified as the congener B. maculata.

Boulengerella differs from Ctenolucia, the only other genus currently contained in the family Ctenolucidae, by a series of derived features including possession of 87-124 (vs. 45-50) lateral line scales, presence of a strongly (vs. weakly) developed fleshy appendage at the tip of the snout and absence (vs. presence) of fleshy flaps on the lower jaw.

Within the order Characiformes the family Ctenoluciidae is also distinguished by a set o…

It’s known by various vernacular names including ‘Pirá-pacu’, ‘Pira-pucu’ or ‘Diente de cao’ (central Amazon), ‘Bicuda’ or ‘Uena’ (rio Tocantins), ‘Bicuda’ (rio Tapajós), ‘Aguejeta’ or ‘Picua’ (Venezuela), and ‘Moruwi’ or ‘Pirapoko’ (Guyana).

The entire dorsal-fin base is located anteriorly to a vertical through the anal-fin origin and this character distinguishes it from all other ctenolucids except B. lucius and B. xyrekes.

This species is sometimes traded as ‘cherry red Congo tetra’ or ‘super red Congo tetra’ and has also been referred to using the misapplied names Alestopetersius nigropterus (a valid congener) and A. ansorgii (a synonym of Nannopetersius ansorgii).

This species appears to be restricted to the Imo and Niger drainages in Nigeria but the full extent of its distribution is unclear.

Type locality is ‘Aba, Lower Niger, Nigeria’, corresponding to the city of Aba in Abia state, southern Nigeria which lies on the Aba River, a tributary of the Imo.

Nigeria has lost 95 % of its original rainforest cover, num…

This species is rare in the aquarium trade but is arguably more suitable for the home aquarium than some of its better-known relatives given its adult size and relatively docile behaviour.

Other vernacular names include ‘Dientón’ (Peru), ‘Perrito’ (Ecuador), ‘Payara-chata’ or ‘Payarin’ (Venezuela) and ‘Icanga’, ‘Minguilista’ or ‘Peice-cachorro’ (Brazil), some of which are also applied to related species.

Vernacular names in Brazil include ‘Cachorra’ or ‘Pirandirá’, although these are also applied to congeners.

It can be told apart from all congeners by the following combination of characters: head and body silvery with dark dorsal surface; an elongate dark blotch posterior to the opercle; dorsal, caudal and anal-fin rays reddish to orange proximally with some individual variation in intensity and tonality; adipose fin dark, with diffuse black pigmentation.

H. armatus should probably not be considered a home aquarium subject at all given its eventual size and migratory natural behaviour.

Unfortunately, juveniles are seen for sale quite regularly, most often without adequate information regarding their long-term care, and it’s common to see them being maintained in medium-sized aquaria with no possibility of achieving their potential.

It’s most similar to A. riesei but can be told apart by its more-elongate body (depth 4-5 times, vs. 3.1-3.5 times, in SL), live body colour (silvery yellow, vs. red) and suborbital bone structure (almost complete, vs. reduced).

The third species, A. lindeae, is quite different posses…