Widely-distributed throughout the Amazon, Orinoco, Essequibo, and Tocantins river systems in Brazil, Peru, Bolivia, Ecuador, Colombia, Venezuela, and Guyana.

Type locality is ‘Rio Cupai [= Rio Cupari], Rio Tapajós basin, Amazon River drainage, Pará State, Brazil’.

Has been collected from habitats containing clear, soft, acidic, tea-coloured blackwater, most typically among leaf litter or submerged vegetation in very shallow (10-50 cm depth) water along the margins of streams and other minor tributaries.

At a village called El Niñal close to the mouth of the rio Pasimoni in the Casiquiare drainage pH was…

Gasteropelecids are commonly-referred to as ‘freshwater hatchetfishes’ due to their heavily-keeled body shape which has evolved in such a way due to possessing an enlarged, heavily-muscled pectoral girdle, and which resembles the shape of a hatchet head.

They are sometimes said to be capable of propelled flight above the water surface by beating their pectoral fins but in fact this is not the case and was disproven by Wiest (1995) who used…

Both species also possesses a broader dark midlateral stripe on the body which tends to be more well-defined in B. lateristriga than in B. maculata.

Colour pattern in B. maculata varies considerably with some specimens noticeably paler than others, for example, and the the broad midlateral stripe usually less intense in such individuals.

This does not app…

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…

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 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).

Décor is relatively unimportant and maintenance simple provided sufficient space is available.

A natural-style arr…

Populations known in the aquarium trade include ‘Cuao’, ‘Orinoco’, ‘San Antonio’, and ‘Sipapo Ventuari’.

B. wavrini and its congener B. cupido can be separated by body shape and position of the dark blotch on the posterior portion of the flank. In B. cupido the body is relatively compact and the blotch located above the upper lateral line, whereas in B. wavrini the body is noticeably elongate and the blotch on or below the upper lateral line.