Rhinolekos capetinga: a new cascudinho species (Loricariidae, Otothyrinae) from the rio Tocantins basin and comments on its ancestral dispersal route

The present study deals with the description of a new species of Rhinolekos. It can be distinguished from its congeners by having 31 vertebrae, the anterior portion of the compound supraneural-first dorsal-fin proximal radial contacting the neural spine of the 9th vertebra, the absence of transverse...

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Detalles Bibliográficos
Autores: Roxo, Fabio F. [UNESP], Ochoa, Luz E. [UNESP], Silva, Gabriel S. C. [UNESP], Oliveira, Claudio [UNESP]
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2015
País:Brasil
Institución:Universidade Estadual Paulista (UNESP)
Repositorio:Repositório Institucional da UNESP
Idioma:inglés
OAI Identifier:oai:repositorio.unesp.br:11449/128619
Acceso en línea:http://zookeys.pensoft.net/articles.php?id=4664
http://hdl.handle.net/11449/128619
Access Level:acceso abierto
Palabra clave:Biodiversity
Freshwater
Neotropical fish
South America
Taxonomy
Descripción
Sumario:The present study deals with the description of a new species of Rhinolekos. It can be distinguished from its congeners by having 31 vertebrae, the anterior portion of the compound supraneural-first dorsal-fin proximal radial contacting the neural spine of the 9th vertebra, the absence of transverse dark bands in the pectoral, pelvic and anal-fin rays, 24-28 plates in the dorsal series, the lack of odontodes on the ventral tip of the snout, the absence of accessory teeth, a greater prenasal length, a smaller head length, and by a greater snout length. Rhinolekos capetinga is restricted to the headwaters of the rio Tocantins and it is the first species of this genus in the Amazon basin. Additionally, we present a brief discussion of a biogeographic scenario that may explain the dispersal of the new species from the rio Paranaiba to the rio Tocantins basin. We suggest that the ancestral lineage of R. capetinga reached the rio Tocantins from portions of the rio Paranaiba at the end of the Miocene, about 6.3 Mya (4.1-13.9 Mya 95% HPD), probably as a result of headwater capture processes among adjacent drainages.