Two new remarkable and endangered catfish species of the genus Cambeva (Siluriformes, Trichomycteridae) from southern Brazil

Abstract

During a field inventory directed at trichomycterine habitats, two new species of the genus Cambeva, C. alphabelardense sp. nov. and C. betabelardense sp. nov., were found in the Rio Chapecó drainage, an area under high environmental decline due to intensive soya monoculture. These species share a peculiar head morphology and some unique osteological features, besides having a size that is smaller than in any other congener, being herein considered to be more closely related to each other than to other taxa. They differ from each other by several characters, including head shape, fin morphology, number of jaw teeth and opercular odontodes, and mesethmoid and metapterygoid shape. Furthermore, they were found in the same area, but in distinct biotopes, with one species found buried in the remnants of tree ferns and other plants on the stream bottom, restricted to a small residual fragment of the original forest, and the other species inhabiting a stream with gravel and small stones on the bottom. Field studies indicate that these species are threatened with extinction. Robust phylogenetic studies are still necessary to test relationship hypotheses involving the new taxa here described.

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

“…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).…”

“…Comparative material is found in Costa (2021), with the addition of Cambeva balios (Ferrer & Malabarba, 2013) (Ferrer & Malabarba, 2013) (UFRJ 6935, 2 C&S), besides specimens of congeners described more recently (Costa et al, 2021a(Costa et al, , 2021b(Costa et al, , 2022. Geographical names correspond to Portuguese names used in the region.…”

“…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.…”

Monophyly or Homoplasy? The Relationships of a Rare New Species of Cambeva (Siluriformes: Trichomycteridae) from the Brazilian Atlantic Forest with a Bicolored Caudal Pattern

“…The genus Cambeva possesses a great diversity of species only recently revealed (e.g., [9,10]). Recent studies have shown us that species of this genus may possess uncommon or unique morphological traits among trichomycterines, but some evidence casually obtained in field studies also suggests unusual behavioral and ecological characteristics (e.g., [10,[42][43][44]). In view of the intense process of environmental degradation throughout the distribution area of the genus, these data demonstrate the urgent need for field studies to better understand these preliminary data on the evolution and ecology of the group.…”

Morpho-Molecular Discordance? Re-Approaching Systematics of Cambeva (Siluriformes: Trichomycteridae) from the Guaratuba-Babitonga-Itapocu Area, Southern Brazil

“…About half of these species belongs to a clade endemic to eastern South America that includes the genera Cambeva Katz, Barbosa, Mattos & Costa, 2018, Scleronema Eigenmann, 1917 and Trichomycterus s.s. Valenciennes, 1832, called the CST-clade [3]. In the last three years, 39 new trichomycterine species of phylogenetic lineages little or not previously known were described from eastern and central South American region [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20], demonstrating that our current knowledge about this group is still at an initial stage. Cambeva, the focus of the present study, includes over 40 species [9], many of them with restricted distribution, occurring between the Rio São Francisco basin in south-eastern Brazil and tributaries of the Lagoa dos Patos system in southern Brazil [21].…”