A new species of Lepidocephalichthys (Teleostei: Cobitidae) with distinctive sexual dimorphism and comments on relationships in southern lineages of Cobitidae

Abstract

Lepidocephalichthys (Telostei: Cobitidae) is diagnosed as being unique among cobitids in having the 7-8th pectoral rays of mature males modified. Recently collected material from Thailand included a new species of Lepidocephalichthys in which mature males have a large (extending over ∼75% of the fin-ray length) dorsally projecting and serrated flange and a ventrally projecting flange. The ventrally projecting structure is unique among cobitids. An expanded phylogenetic analysis of cobitids, including previously published sequences and new material including the new species, reinforces the monophyly of Lepidocephalichthys. Relationships within southern lineages of cobitids, and the unusual habitat of the new species are discussed. © 2010.