Relationships and description of a new catfish species from Chapada Diamantina, the northernmost record of Trichomycterus s.s. (Siluriformes, Trichomycteridae)

• Published in: Zoosystematics and Evolution 2024-03, Vol.100 (1), p.223-231
• Main Authors: Costa, Wilson J. E. M., Feltrin, Caio R. M., Mattos, José L. O., Katz, Axel M.
• Format: Article
• Language: English
• Subjects: Bats; Biodiversity; Cytochrome; Endemic species; Fins; Genes; Geographical distribution; Morphology; New species; Phylogenetics; Phylogeny; Physical characteristics; Siluriformes; Trichomycterus
• ISSN: 1435-1935; 1860-0743
• DOI: 10.3897/zse.100.115564

Psammocambeva exhibits the largest geographical distribution amongst the subgenera of Trichomycterus s.s. , with its present northernmost represented by Trichomycterus tete , endemic to the upper Rio de Contas Basin in the Chapada Diamantina Region, north-eastern Brazil. Herein, we describe a new species recently collected in the Chapada Diamantina Region, but in the Rio Paraguaçu Basin, about 100 km north of the area inhabited by T. tete . A molecular phylogeny using one nuclear and two mitochondrial genes (2430 bp) supported the new species as sister to T. tete ; both species are distinguished by colour patterns, morphometric data, relative position of dorsal and anal fins and osteological character states. The clade comprising the new species and T. tete , endemic to the semi-arid Caatinga biogeographical province, is supported as sister to a clade comprising species from the Rio Doce and Rio Paraíba do Sul Basins, in the Atlantic Forest biogeographical province. This study corroborated the Chapada Diamantina Region, a well-known mountainous biodiversity centre, as an important centre of endemism for trichomycterid catfishes.