Systematics of tetras (genera Hemigrammus, Hyphessobrycon, Thayeria, Parapristella, and Bryconella), with emphasis on the species from the northern cis-andean South America.

Abstract

The species comprehended by the genera Hyphessobrycon, Hemigrammus, Thayeria, Parapristella, and Bryconella, currently allocated either as a "Incertae sedis" or within the subfamily Tetragonopterinae (family Characidae), the so-called "tetras", are among the most taxonomically-challenging species assemblage within South American freshwater fishes. The present project intends to advance considerably our knowledge on the taxonomy/systematics of the species belonging to these genera, which currently encompasses 184 valid species. A sizable portion of the diversity within these genera will be re- evaluated taxonomically, aiming at producing modern diagnoses, evaluating the geographic variation, and adequately map the distribution for each studied species. It is predictable that many undescribed species will be identified and formally described during the course of the project. Although this assemblage of genera/species probably does not constitute a natural, monophyletic entity, it is argued herein that taxonomy has a logical priority over phylogenetic reconstruction and that the efforts conducted during the present project will be of great help to guide future attempts aiming at establishing solid phylogenetic hypotheses for the family Characidae. (AU)