Rafael Costa Angrizani, Luiz Roberto Malabarba

Abstract

More than 100 species have been referred to Rhamdia since its description, but in the last revision of the genus more than two decades ago, only eleven species have been considered as valid. Rhamdia quelen was then redefined to include 47 junior synonyms, resulting in a species with a large distribution in the Neotropics, from Mexico to Argentina. Populations of Rhamdia from west of the Andes have been recently removed from the synonymy of R. quelen, and currently there are 27 species recognized in the genus. Most cis-Andean populations, however, remain referred to the R. quelen species complex. In this paper, we use species delimitation methods and multilocus phylogenetic analyses to delimit the species contained in the R. quelen species complex in cis-Andean river drainages. Eighteen MOTUs in the gene tree were recovered with high support. We further demonstrate that the previous designation of a neotype for R. quelen is invalid, and has to be replaced by the proper designation of a neotype from the type locality of the species. The neotype is designated herein and R. quelen is diagnosed and redescribed.

https://www.mapress.com/j/zt/article/view/zootaxa.4801.1.3

Figure 3. Species tree produced by Starbeast in Beast 1.8.4. Dark gray highlight: the trans-Andean clade; light gray highlight: the cis-Andean clade; dark green highlight: the Amazon clade (AM); light green highlight: the Upper Amazon clade (PE); pink highlight: the non-Amazon clade; blue highlight: the Continental clade (CC); orange highlight: the Atlantic clade; red highlight: the Lowland clade (LA); yellow highlight: Highland clade (HA). The terminals are different lineages recovery for the bayesian analyses.

Figure 4. Neotype of Rhamdia quelen by present designation. MNRJ 51746, Brazil, Rio de Janeiro State, Cachoeira de Macacu, tributary of the Rio Soarinho, tributary of the Rio Macacu, Baía de Guanabara (22o38’6”S 42o43’6”W).