Cambeva diffusa

description

(Figs 1, 11 A, 12 A, 13 A; Table 1) urn: lsid: zoobank. org: act: 5 C 3 D 95 DE- 504 C- 49 EB-B 20 D- 83 B 9 D 446381 A

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

description

DESCRIPTION General morphology Morphometric data in Table 1. Body moderately slender, subcylindrical anteriorly to compressed posteriorly. Greatest body depth in area just anterior to pelvic-fin base. Dorsal and ventral profiles of head and trunk slightly convex, approximately straight on caudal peduncle. Skin papillae minute. Anus and urogenital papilla in vertical through anterior third of dorsal-fin base. Head trapezoidal in dorsal view, anterior profile of snout convex. Eye small, dorsally positioned in anterior half of head. Posterior nostril located nearer anterior nostril than orbital rim. Tip of maxillary barbel reaching middle of interopercular patch of odontodes; tip of rictal barbel reaching area just anterior to interopercular patch of odontodes; tip of nasal barbel reaching anterior portion of orbit. Mouth subterminal. Jaw teeth slightly pointed to incisiform, slightly curved in premaxilla and strongly curved in dentary, irregularly arranged, 36 - 45 in premaxilla, 33 - 46 in dentary. Branchial membrane attached to isthmus only at its anterior point. Branchiostegal rays 8. Cranial fontanels present, posterior fontanel long, anteriorly extending between frontals to reac

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

diagnosis

DIAGNOSIS. — Cambeva diffusa n. sp. is distinguished from all other species of the C. balios complex by the presence of a lighter general colouration, highly differing by the presence of a great concentration of small dark brownish grey dots in a superficial skin layer, contrasting with rounded diffuse pale grey spots, almost inconspicuous, in a deeper layer (Fig. 1; vs never a similar colouration, Fig. 2; see also Ferrer & Malabarba 2013: fig. 1). Cambeva diffusa n. sp. is similar to C. pericoh n. sp. and distinguished from C. balios in having a slightly posteriorly folded extremity of the dorsal process of the opercle (Fig. 12 A, vs unfolded), a narrow postero-dorsal projection on the preopercle (Fig. 12 A, vs no projection), and eight branchiostegal rays (vs nine). Cambeva diffusa n. sp. differs from C. pericoh n. sp. in having more dorsal procurrent caudal-fin rays (17, vs 13 or 14), fewer ribs (12, vs 15), and opercular and interopercular postero-dorsal odontodes distinctively wider and more curved than other odontodes (Fig. 12 A; vs opercular and interopercular posterodorsal odontodes only slightly wider and more curved than other odontodes, Fig. 12 B).

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

distribution

DISTRIBUTION. — Cambeva diffusa n. sp. occurs in the western open plateau. It is known from three localities in the upper Rio Canoas drainage, Rio Uruguai basin, in altitudes between about 910 and 940 m asl (Fig. 14).

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