Field inventory reveals high diversity of new species of mountain catfishes, genus Cambeva Katz, Barbosa, Mattos & Costa, 2018 (Siluriformes: Trichomycteridae), in south-eastern Serra Geral, southern Brazil

A new catfish species of the genus Cambeva (Siluriformes: Trichomycteridae) from the Rio Iguaçu drainage, southern Brazil, with a remarkable unique colour pattern

“…Although knowledge of species diversity within Cambeva has quickly increased with descriptions of several new species in the past 10 years, knowledge of species relationships is still incipient, limited to weak monophyly hypotheses of some species groups based on a few morphological characters (Costa et al ., 2020b, 2021a, 2021b; Wosiacki & de Pinna, 2008a) or low sampling of taxa in molecular phylogenetic approaches (dos Reis et al ., 2019; Katz et al ., 2018; Ochoa et al ., 2017). Similarly, the possible monophyly of a group including C. castroi , C. melanoptera and C. diabola (hereafter C. castroi group) is tentative, only supported by all having a similar colour pattern of the caudal fin, in which the distal dark portion of the fin highly contrasts with the light proximal portion (see aforementioned diagnosis).…”

“…In fact, more recent intensive field studies in the upper Rio Uruguai basin have revealed a high number of endemic species similar to or higher than that recorded for the Rio Iguaçu drainage if including species still undescribed (Costa et al ., 2020b, 2021b, 2022). Osteological data have indicated that species of the upper Rio Uruguai basin are closely related to species endemic to the Lagoa dos Patos system, with these two areas sharing species groups that are not known to occur in the Rio Iguaçu drainage (Costa et al ., 2020b, 2021b).…”

“…The protocol described by Taylor and van Dyke (1985) was used to clear and stain specimens (C&S in lists of specimens) for osteological examination. Osteological structures are those presenting informative variability among congeners (Costa et al ., 2020b, 2021a, 2021b), including the upper jaw and adjacent structures, jaw suspensorium, opercular series and parurohyal. Osteological terminology follows Costa (2021).…”

“…Terminology for the cephalic latero‐sensory system is according to Arratia and Huaquin (1995), as modified by Bockmann and Sazima (2004). Comparative material is found in Costa (2021), with the addition of Cambeva balios (Ferrer & Malabarba, 2013) (UFRJ 7024, 2 C&S), C. castroi (UFRJ 9760, 3; UFRJ 10670, 2 C&S; UFRJ 10197, 1; UFRJ 10857, 3), C. diabola (UFRJ 7009, 8; UFRJ 7010, 2 C&S); Cambeva perkos (Datovo et al ., 2012) (UFRJ 7025, 3 C&S) and Cambeva tropeira (Ferrer & Malabarba, 2013) (UFRJ 6935, 2 C&S), besides specimens of congeners described more recently (Costa et al ., 2021a, 2021b, 2022). Geographical names correspond to Portuguese names used in the region.…”

“…120 species. Nonetheless, the number of species included in Cambeva is quickly increasing since the genus description, presently reaching 40 valid species and others waiting formal description (Costa et al ., 2021a, 2021b; dos Reis et al ., 2021).…”