Phylogenetic relationships within the speciose family Characidae (Teleostei: Ostariophysi: Characiformes) based on multilocus analysis and extensive ingroup sampling

Abstract

BackgroundWith nearly 1,100 species, the fish family Characidae represents more than half of the species of Characiformes, and is a key component of Neotropical freshwater ecosystems. The composition, phylogeny, and classification of Characidae is currently uncertain, despite significant efforts based on analysis of morphological and molecular data. No consensus about the monophyly of this group or its position within the order Characiformes has been reached, challenged by the fact that many key studies to date have non-overlapping taxonomic representation and focus only on subsets of this diversity.ResultsIn the present study we propose a new definition of the family Characidae and a hypothesis of relationships for the Characiformes based on phylogenetic analysis of DNA sequences of two mitochondrial and three nuclear genes (4,680 base pairs). The sequences were obtained from 211 samples representing 166 genera distributed among all 18 recognized families in the order Characiformes, all 14 recognized subfamilies in the Characidae, plus 56 of the genera so far considered incertae sedis in the Characidae. The phylogeny obtained is robust, with most lineages significantly supported by posterior probabilities in Bayesian analysis, and high bootstrap values from maximum likelihood and parsimony analyses.ConclusionA monophyletic assemblage strongly supported in all our phylogenetic analysis is herein defined as the Characidae and includes the characiform species lacking a supraorbital bone and with a derived position of the emergence of the hyoid artery from the anterior ceratohyal. To recognize this and several other monophyletic groups within characiforms we propose changes in the limits of several families to facilitate future studies in the Characiformes and particularly the Characidae. This work presents a new phylogenetic framework for a speciose and morphologically diverse group of freshwater fishes of significant ecological and evolutionary importance across the Neotropics and portions of Africa.

The brain of Brycon orbignyanus (Valenciennes, 1850) (Teleostei: Characiformes: Bryconidae): gross morphology and phylogenetic considerations

“…1-3). Also, in many significant past papers the genus Brycon was considered "primitive", "generalized" or phylogenetically basal in the Neotropical Characiformes, or at least in relation to the Characidae, sharing several osteological features with basal African groups (see Weitzman, 1962;Buckup, 1998;Mirande, 2009Mirande, , 2010Weitzman, 2003 andOliveira et al, 2011).…”

“…Characiformes contains approximately 2,100 valid living species, occurring mostly in the freshwaters of the Neotropical region (19 families) and less so in the African Sub-Saharan region of Africa (four families) (Reis et al, 2003;Oliveira et al, 2011). As with other teleostean groups, the clades within the Characiformes are diagnosed and have their evolutionary interrelationships hypothesized almost exclusively with osteological characters (Fink & Fink, 1981, 1996.…”

“…These Otophysi brain studies have unequivocally shown that the central nervous system can be an important source of phylogenetically informative morphological characters, although relatively unexplored. Bearing that in mind, we have chosen Brycon orbignyanus, a member of the putative generalized and phylogenetically basal family Bryconidae (Roberts, 1969;Mirande, 2009Mirande, , 2010Oliveira et al, 2011), to be described as an example of a generalized Characiformes brain.…”

Two new species and a review of the inseminating freshwater fish genus Monotocheirodon (Characiformes: Characidae) from Peru and Bolivia

“…After its inclusion with inseminating clade A characids (Weitzman et al, 2005) and subsequently the subfamily Stevardiinae (Mirande, 2010;Oliveira et al, 2011) the first attempt to resolve the relationships of Monotocheirodon with the other stevardiin genera was by Ferreira et al (2011). This involved 153 characters, including features of morphology, reproduction and sperm ultrastructure.…”

“…Their phylogenetic relationships were not resolved and as emphasized by Ferreira et al (2011) were depicted as forming a large polytomy. This subfamily was also utilized as the representative taxon of Clade A characids along with Markiana nigripinnis analyzed in a recent molecular study (Oliveira et al, 2011). The present contribution is designed to describe the two new species of Monotocheirodon, redefine this genus, and briefly discuss its relationships with the other members of the subfamily Stevardiinae.…”