Pogonopoma obscurum: A New Species of Loricariid Catfish (Siluriformes: Loricariidae) from Southern Brazil, with Comments on the Genus Pogonopoma

The loricariid genus Pogonopoma Regan, 1904, is revised and expanded to include Pogonopomoides parahybae and a new species, Pogonopoma obscurum, from the upper rio Uruguai, southern Brazil. The new species can be distinguished from its congeners by having eight to 11 branched dorsal fin rays, versus seven in the remaining species. The phylogenetic placement and geographic distribution of the new species are evaluated and discussed. An identification key for the genera of the Rhinelepis group of the subfamily Hypostominae and for the species of Pogonopoma is provided.

Resumen

O gênero de Loricariidae Pogonopoma Regan, 1904, é revisado e ampliado para incluir Pogonopomoides parahybae e uma espécie nova, Pogonopoma obscurum, descrita do rio Uruguai superior no sul do Brasil. A nova espécie distingue-se das outras por possuir de oito a 11 raios ramificados na nadadeira dorsal, versus sete nas demais espécies. A posição filogenética e a distribuição geográfica da nova espécie são avaliadas e discutidas. Uma chave de identificação para os gêneros do grupo Rhinelepis da subfamilia Hypostominae e para as espécies de Pogonopoma é fornecida.

Fig. 1.

Single most-parsimonious phylogenetic tree of the Rhinelepis group. Steps 67, consistency index 0.56, retention index 0.67. Characters and states (in parenthesis) follow Armbruster (1998a); character 41 from this study; R = reversal, C = convergence

Fig. 2.

Distribution of Pogonopoma species. Squares: Pogonopoma obscurum n. sp.; triangles: Pogonopoma parahybae; and circles: Pogonopoma wertheimeri—open square represents type-locality. 1, upper rio Uruguai; 2, rio Paraíba do Sul; 3, rio Doce; 4, rio São Mateus; and 5, rio Mucuri

Fig. 3.

Pogonopoma obscurum n. sp., holotype, MCP 25036, 236.8 mm SL, rio Canoas at road from Anita Garibaldi to Abdon Batista, Santa Catarina, Brazil

Fig. 4.

Drainage basin relationships based on the phylogenetic analysis of the species in the Rhinelepis group (modified from Arbruster, 1998a, by the inclusion of the rio Uruguai)

Accepted: 07 Dec 2001