A New Miniature Characid (Ostariophysi: Characiformes: Characidae), with Phylogenetic Position Inferred from Morphological and Molecular Data

Abstract

Erythrocharax altipinnis is described from the Serra do Cachimbo, Pará, Brazil. The new taxon is distinguished from all of the Characidae genera by having the pelvic bones firmly attached through the isquiatic processes; a nearly triangular hiatus in the musculature covering the anterior chamber of the swim bladder between the first and second pleural ribs (pseudotympanum); the pedunculate, notably expanded and distally compressed teeth in both jaws; circumorbital series represented by antorbital and four infraorbital bones with laterosensory canals not enclosed; a single tooth row in the premaxillary with the teeth perfectly aligned and similar in shape and cusp number; the first three branched dorsal-fin rays distinctly elongate in males; a bright red adipose and caudal fins in life; a conspicuous dark midlateral stripe extending from the opercle to the tip of the median caudal-fin rays; and by the absence of a humeral spot. The phylogenetic position of the new taxon is discussed using morphological and molecular datasets, with conflicting results of both approaches discussed. Additionally, a summarized discussion on the current problems in the Characidae taxonomy is presented and the principal biases in the morphological dataset are also discussed.

Ontogenetic changes in mouth morphology triggers conflicting hypotheses of relationships in characid fishes (Ostariophysi: Characiformes)

“…The single tooth series in the premaxilla, however, has been demonstrated by direct homology (Malabarba, 1998) or by parsimony analyses (e.g. Paracheirodon Géry by Weitzman, Fink, 1983; Charax Gronow by Lucena, 1987; "the Rosy Tetras Clade" by Weitzman, Palmer, 1997; Xenurobryconini by Weitzman, Fink, 1985;Netto-Ferreira et al, 2013) to originate several times and independently in different genera of the Characidae. Malabarba (1998) identified three non-homologous origins of a single tooth series in Characidae: (1) the merging of both rows into a single one; (2) the reduction of the anterior tooth row, with one or even two teeth remaining and not perfectly aligned in a single series; and, (3) the complete loss of the anterior tooth row.…”

Molecular phylogeny of Moenkhausia (Characidae) inferred from mitochondrial and nuclear DNA evidence

“…In a recent article, Netto‐Ferreira et al. () described a new genus and species, Erythrocharax altipinnis , and found this genus to be the sister group of a clade composed by P. cyclolepis and Macropsobrycon xinguensis . We added the molecular information about E. altipinnis and M. xinguensis to our database and we found the following relationship [ Erythrocharax altipinnis ( Parecbasis cyclolepis ( Moenkhausia cotinho , Macropsobrycon xinguensis ))] with 66% confidence in the ML partitioned analyses, reinforcing the idea that this group should be better analysed in further studies.…”

A history of the biogeography of Amazonian fishes

“…Roberts' (1972) hypothesis has been repeatedly corroborated and colorful characin species are indeed far more numerous in clear-or blackwater rivers and streams (cf. Bertaco, Carvalho, 2005a, 2005bCarvalho, Bertaco, 2006;Lima, Birindelli, 2006;Lima et al, 2007;Bertaco, Malabarba, 2007;Sousa et al, 2010;Bertaco et al, 2011;Ingenito et al, 2013;Mattox et al, 2013;Netto-Ferreira et al, 2013;Marinho et al, 2014;Pastana, Dagosta, 2014;Dagosta et al, 2015;Ohara, Lima, 2015).…”