The taxonomy of the nominal species of giant trahiras Hoplias aimara (Valenciennes, 1846) and Hoplias macrophthalmus (Pellegrin, 1907), both described from Cayenne (French Guiana), was evaluated to determine whether they constitute distinct forms and to determine the geographic distribution of the recognized species. A total of 200 specimens were examined (30–624 mm standard length). Analysis of meristic and morphometric data resulted in the recognition of a single species. Study of the type-specimens revealed that both species names, H. aimara and H. macrophthalmus, refer to the same taxon. According to the Principle of Priority of the International Code of Zoological Nomenclature the name Hoplias aimara has precedence. This species is distinguished from congeners by the presence of a vertically-elongate dark spot on the median portion of the opercular membrane and by the absence of the accessory ectopterygoid. Hoplias aimara occurs in the drainages of Rio Tocantins, Rio Xingu, Rio Tapajós, Rio Jarí, and Rio Trombetas, in coastal drainages of the Guyanas, Suriname, and state of Amapá, Brazil. In the Río Orinoco basin, the species occurs only in the Río Caroní and rivers to the east of this drainage. Literature records of Hoplias aimara for the Rio Purus and upper Río Orinoco were based on misidentifications. This pattern of geographic distribution of Hoplias aimara in rivers of the Guyanas and Brazilian Shields also occurs in other Neotropical species of fishes.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 2006 • No. 3