Abstract
A new genus and species of characid fish is described from rio Braço Norte, a tributary of rio Teles Pires, Tapajós basin, Mato Groso, Brazil. The new taxa can be diagnosed from the remaining characids by a unique combination of characters that includes the presence of a single row of relatively compressed premaxillary teeth, large teeth with four to nine cusps on premaxillary and dentary, absence of pseudotympanum, incomplete lateral line with 7–13 pored scales, sexually-dimorphic males with distal margin of anal fin approximately straight, and presence of a nearly triangular and horizontally elongated blotch from the posterior half of the body to caudal peduncle. The most parsimonious phylogenetic hypothesis, using morphological data, recovered the new genus and species in a clade including Paracheirodon axelrodi and Hyphessobrycon elachys.
Highlights
The Characidae is one of the richest families among bony fishes, and depending of the alternative proposals followed [1,2], the family comprise between 1,100 to over than 1,200 species [3]
The aim of the present study is to describe this new taxon, assigned to a new genus, due to both phylogenetic position and unique combination of characters
Diagnosis: Phycocharax can be diagnosed from the remaining characid genera by the combination of the following character-states, none of them unique: 1) presence of single row of relatively compressed premaxillary teeth (Fig 2); 2) large teeth on premaxillary, and dentary with four to nine cusps (Fig 2); 3) pseudotympanum absent; 4) incomplete lateral line with 7–13 pored scales; 5) anal fin dimorphic, males with distal margin approximately straight, and decreasing gently posteriorly (Figs 1a and 3a), while females present slightly concave margin of anal fin with anteriormost branched rays distinctly longer than remaining rays (Figs 1b and 3b); 6) presence of horizontally-elongated somewhat triangular blotch extending from vertical through dorsal-fin terminus to caudal peduncle end (Figs 1 and 3)
Summary
The Characidae is one of the richest families among bony fishes, and depending of the alternative proposals followed [1,2], the family comprise between 1,100 to over than 1,200 species [3]. Much advance to understand the relationships within Characidae family has been accomplished, it still constitutes in an unsettled issue. A stable classification of the Characidae is still far to be established, given the great diversity and complexity of the family and the lack of comprehensive analysis combining morphological and molecular data [4]. Many members of the Characidae have low variation either in molecular data [2] as in morphological [5,6], and most deep relationships within the family are incongruent between different analysis or have low support. The new taxon is described due to its unusual combination of single row of compressed premaxillary teeth, pseudotympanum absent, and sexual dimorphism with males exhibiting a straight distal margin of the anal fin, PLOS ONE | DOI:10.1371/journal.pone.0170648 February 15, 2017
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
