A new large species of Myloplus (Characiformes, Serrasalmidae) from the Rio Madeira basin, Brazil.
Myloplus zorroi sp. n. is described from the Rio Madeira Basin in Amazonia. The new species had been treated as an undescribed Tometes species because of the absence of a marked abdominal keel and few small spines forming its prepelvic serrae, features commonly found in the species of the Myleus clade of the Serrasalmidae (species of genera Myleus, Mylesinus, Ossubtus and Tometes) and also in species of Utiaritichthys. Myloplus zorroi sp. n. shares the following characters with its congeners and Utiaritichthys: molariform teeth (versus incisiform teeth in Myleus clade members); a labial row of premaxillary teeth separated from lingual row by an internal gap (versus absence of internal gap between premaxillary teeth rows); and an ascending process of premaxilla wide from its base to the tip (versus ascending process tapering from its base to the tip). Like other Myloplus species, Myloplus zorroi sp. n. differs from Utiariticthys by having a deeper body, approximately 60% of standard length (versus usually less than 50% of standard length). Considering all the morphological evidence, including the presence of 13-19 low spines forming the prepelvic serrae in Myloplus zorroi sp. n. versus more than 20 high spines forming a marked prepelvic keel in other species of Mylopus, the new species is here assigned to Myloplus. Comparisons of the new species with nominal species of Myloplus, representatives of the Myleus clade, and other related taxa are provided.
Universidade Federal do Pará, Cidade Universitária Prof. José Silveira Netto. Laboratório de Biologia Pesqueira e Manejo dos Recursos Aquáticos, Grupo de Ecologia Aquática. Avenida Perimetral, 2651, Terra Firme, 66077830. Belém, PA, Brazil; Programa de Pós-Graduação em Ecologia Aquática e Pesca. Universidade Federal do Pará, Instituto de Ciências Biológicas. Cidade Universitária Prof. José Silveira Netto. Avenida Augusto Corrêa, 1, Guamá, 66075110. Belém, PA, Brazil.
Marcelo C
MC
Andrade
Institut de Recherche pour le Développement, Biologie des Organismes et Ecosystèmes Aquatiques, UMR BOREA, Laboratoire d´Icthyologie, Muséum national d'Histoire naturelle, MNHN, CP26, 43 rue Cuvier, 75231 Paris Cedex 05, France.
Michel
M
Jégu
Universidade Federal do Pará, Cidade Universitária Prof. José Silveira Netto. Laboratório de Biologia Pesqueira e Manejo dos Recursos Aquáticos, Grupo de Ecologia Aquática. Avenida Perimetral, 2651, Terra Firme, 66077830. Belém, PA, Brazil; Programa de Pós-Graduação em Ecologia Aquática e Pesca. Universidade Federal do Pará, Instituto de Ciências Biológicas. Cidade Universitária Prof. José Silveira Netto. Avenida Augusto Corrêa, 1, Guamá, 66075110. Belém, PA, Brazil; Programa de Pós-Graduação em Biodiversidade e Conservação. Universidade Federal do Pará, Faculdade de Ciências Biológicas. Avenida Cel. José Porfírio, 2515, São Sebastião, 68372010. Altamira, PA, Brazil.
Tommaso
T
Giarrizzo
Myleus; Ostariophysi; freshwater fish; pacu; rapids; taxonomy