No abstract

The taxonomy of the common guppy, Poecilia reticulata Peters, 1859, is reviewed and the closely related Campoma guppy, P. wingei n. sp., is described. Formerly, the common guppy was not judged to be closely related to any other species of Poecilia, but the new species is the second species to be allocated in the subgenus Acanthophacelus Eigenmann, 1907. The recognition of P. wingei results from observed character displacement, i.e., on the interaction between two closely related species in a shared environment. In addition to differences in coloration, behaviour also indicates specific differences. The area in which P. wingei occurs, the Campoma region at the base of the Paría Peninsula in Venezuela, hints to an origin of the subgenus Acanthophacelus prior to the uplift of the Cordilleras, i.e., the eastern orogenesis of the Andes. Moreover, an explanation is offered for aberrant molecular data in Trinidadian guppies.

Pyxiloricaria menezesi n. gen., n. sp., is described and illustrated from Rio Miranda (Est. Mato Grosso do Sul) and from Rio Cuiabá (Est. Mato Grosso), Brazil. It is assigned to the subtribe Planiloricariina of the tribe Loricariini, subfamily Loricariinae. A comparison is made with sympatric Pseudohemiodon cf. laticeps (Regan, 1904).

Descriptions and illustrations are given of four species of mailed catfishes belonging to the subfamily Loricariinae, tribe Harttiini. Two species are assigned to Lamontichthys P. de Miranda Ribeiro, 1939: Lamontichthys filamentosus (La Monte, 1935) (type-species, of which Harttia filamentissima C. H. Eigenmann & Allen, 1942, is provisionally considered a junior synonym), based on a total of thirteen specimens, including all type-specimens, from Brazil, Bolivia, Peru, and Ecuador (all from tributaries of the Rio Amazonas system), and Lamontichthys stibaros n. sp., based on two specimens from Ecuador, sympatric with the former species.