Validity, phylogenetic relationships and redescription of Eremophilus candidus Ribeiro, 1949 (Teleostei, Siluriformes, Trichomycteridae)

Abstract

Trichomycterus candidus (Ribeiro, 1949), originally described in Eremophilus Humboldt, 1805, is redescribed based on the examination of recently collected specimens and type material. The species is diagnosed based on four autapomorphies: enlarged dorsal projection of interopercular patch of odontodes, lack of pelvic fins and girdle, head small and color pattern presenting very small dark brown round spots. The new combination for T. candidus is proposed on the basis of its close relationships with a clade of Trichomycterus from southeastern Brazil, with which it shares four synapomorphies (posterior ceratohyal tip reduced in depth, ventro-posterior process of the posterior ceratohyal absent or vestigial, smaller depth of the posterior projection of opercular patch of odontodes, and color pattern presenting dark brown round spots). Trichomycterus candidus shares with E. mutisii the absence of pelvic fins and girdle, but not the apomorphic pattern of sensorial pores recently established for Eremophilus.