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 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.

Known only from the rio Uaupés system in Brazil with type locality ‘brook emptying into Igarape Yavuari River, tributary of River Uaupés, upper Negro River basin, 0°14’31″N, 68°03’48″W, Amazonas, Brazil’.

The full extent of its range is unclear but additional populations may exist.

This species is quite common in the aquarium trade although normally misidentified as the congeners C. nattereri or the very similar C. meinkeni.

It was considered synonymous with C. nattereri for a number of years and was also referred to as C. cf. meinkeni by Zarske and Géry (2006) befo…

This species has been widely referred to as the congener C. nattereri in aquarium literature both prior to and post-publication of its official description in 2006.

The two can be told apart quite easily by the fact that C. nattereri possesses a dark lateral stripe while C. meinkeni does not.

C. meinkeni can be distinguished from all congeners by the followi…

This species is sometimes traded as C. sp. ‘red line’, ‘spotted tetra’ or as its congener C. nigrofasciata.

In the past it’s name was also widely applied to the fish now identified as C. callolepis and C. meinkeni, and this misidentification continues to an extent although the two are easily-distinguished by the fact that C. nattereri is the only one of the three possessing a dark lateral stripe on each side of the body.

This species was described from a single specimen and included in the genus Leporinus until 2011 at which point the holotype was examined and recognised as corresponding to the fish described as Synaptolaemus cingulatus (Myers & Fernández-Yépez, 1950).

Known from the middle and upper Amazon river basins in Brazil, Peru, Ecuador and Colombia.

Type locality is ‘Amazon River at Obidos, Cudajas, and Tabatinga; Rio Negro, Brazil.’

It apparently practises an interesting reproductive strategy in which the eggs are deposited in a shallow depression excavated from the substrate and guarded by the male.