Abstract
A new Hemigrammusis described from the rio Paraguai and rio Madeira basins, Mato Grosso and Rondônia States, Brazil. The new species is characterized by possessing a wide dark horizontal stripe across the eye, a vertically elongated humeral blotch, and 4-5 gill-rakers on upper branch and 9-10 on lower. The new species can be easily diagnosed from H. lunatus, the sympatric and morphologically most similar congener, by the shape of humeral blotch and the number of gill rakers. Data of the type material of both Hemigrammus lunatus and H. maxillaris, as well as extensive examination of specimens, allowed us to conclude that H. maxillarisis a junior subjective synonym of H. lunatus. A redescription of H. lunatus, as well as a formal restriction of its type locality, is provided. A putative monophyletic group within Hemigrammus, composed by H. barrigonae, Hemigrammus lunatus, H. machadoi new species, and H. ulreyi, named Hemigrammus lunatus group, is proposed based on overall body morphology and color pattern. Additionally, a discussion on the biogeographical relationships between the rio Paraguai and rio Guaporé basins is provided.
Highlights
Hemigrammus Gill is a speciose Characidae genus (54 species currently recognized as valid; Lima et al, 2003; Lima & Sousa, 2009; Carvalho et al, 2010; Mendonça & Wosiacki, 2011; Zarske, 2011) widespread in cis-Andean South America, including the Amazon, Orinoco, La Plata, and São Francisco river basins, and rivers of Guyana, Suriname, French Guyana, and northeastern Brazil
We have examined very few specimens of H. lunatus from western Amazon other than from the rio Madeira basin and for the moment we refrain from discussing their presumable conspecificity with the populations from Central Amazon, rio Madeira, and rio Paraguai basins
Specimens belonging to Hemigrammus machadoi were previously identified by Durbin in Eigenmann (1918: 165) as atypical specimens of H. lunatus
Summary
Hemigrammus Gill is a speciose Characidae genus (54 species currently recognized as valid; Lima et al, 2003; Lima & Sousa, 2009; Carvalho et al, 2010; Mendonça & Wosiacki, 2011; Zarske, 2011) widespread in cis-Andean South America, including the Amazon, Orinoco, La Plata, and São Francisco river basins, and rivers of Guyana, Suriname, French Guyana, and northeastern Brazil. These genera are conveniences rather than entities”. Durbin (in Eigenmann, 1918), remains the sole comprehensive taxonomic revision of Hemigrammus. Since the number of valid species within the genus has more than doubled (from 25 to the present 54), demonstrating that much taxonomical work is still required on the group
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.
