Cambeva pericoh E. & Costa & M. & Feltrin & Katz 2021, n. sp

Cambeva pericoh n. sp. (Figs 2, 11B, 12B, 13B; Table 2) urn:lsid:zoobank.org:act: 324271D3-7113-4CE0-8D00-D47AA56C67B7 MATERIAL EXAMINED. — Holotype. Brazil • 1 ex., 97.3 mm SL; Santa Catarina State: São Joaquim Municipality: village of Pericó: Rio Pericó, tributary of Rio Lava-Tudo, Rio Pelotas drainage, Rio Uruguai basin; 28°09’40”S, 49°45’21”W; about 1170 m asl; C. R. M. Feltrin; 14.III.2021; UFRJ 6969. Paratypes. Brazil • 3 ex., 26.7-59.9 mm SL; collected with holotype; UFRJ 6970 • 2 ex., 28.3-52.0 mm SL; Rio Lava-Tudo; 28°08’43”S, 49°42’40”W; about 1210 m asl; C. R. M. Feltrin; 14.III.2021; UFRJ 6971 • 2 ex. (C&S), 65.1-74.4 mm SL; Rio Pericó; 28°09’40”S, 49°45’21”W; about 1170 m asl; C. R. M. Feltrin; 8.II.2021; UFRJ 6972. DIAGNOSIS. — Cambeva pericoh n. sp. is distinguished from all other species of the C. balios complex by the presence of large black blotches irregularly arranged and often partially coalesced on the flank (Fig. 2; vs never a similar colouration, Fig. 1; see also Ferrer & Malabarba, 2013: fig. 1). Cambeva pericoh n. sp. is similar to C. diffusa n. sp. and distinguished from C. balios in having a slightly posteriorly folded extremity of the dorsal process of the opercle (Fig. 12B, vs unfolded), a narrow postero-dorsal projection on the preopercle (Fig. 12A, vs no projection), and eight branchiostegal rays (vs nine). Cambeva pericoh n. sp. differs from C. diffusa n. sp. in having fewer dorsal procurrent caudal-fin rays (13 or 14, vs 17), more ribs (15, vs 12), and opercular and interopercular postero-dorsal odontodes only slightly wider and more curved than the other odontodes (Fig. 12B; vs opercular and interopercular postero-dorsal odontodes distinctively wider and more curved than the other odontodes, Fig. 12A). DISTRIBUTION. — Cambeva pericoh n. sp. occurs in the western open plateau. It is known from three localities in the Rio Pelotas drainage, upper Rio Uruguai basin, in altitudes between about 1170 and 1210 m asl (Fig. 14). ETYMOLOGY. — The name pericoh is an allusion to the occurrence of the new species in the Rio Pericó, its type locality. The name probably has a Tupi-Guarani origin, but its meaning is uncertain. DESCRIPTION General morphology Morphometric data in Table 2. 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 area just anterior to interopercular patch of odontodes; tip of rictal barbel reaching preopercular area in vertical through orbit; tip of nasal barbel posteriorly reaching anterior portion of orbit or area just anterior to it. Mouth subterminal. Jaw teeth slightly pointed to incisiform, slightly curved in premaxilla and strongly curved in dentary, irregularly arranged, 39-43 in premaxilla, 48-50 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 reach transverse line close to lateral sphenotic process. Dorsal and anal fins subtriangular, distal margin slightly convex; total dorsal-fin rays 12 (iii + I-II + 7-8), total anal-fin rays 10 (iii + II + 5); anal-fin origin in vertical through middle dorsal-fin base. Dorsal-fin origin in vertical through centrum of 22nd vertebra; anal-fin origin in vertical through centrum of 26th vertebra. Pectoral fin subtriangular in dorsal view, posterior margin slightly convex, first pectoral-fin ray not terminating in filament; total pectoral-fin rays 7 (I + 6). Pelvic fin subtruncate, its extremity in vertical through dorsal-fin origin or just anterior to it; pelvic-fin bases medially in close proximity; total pelvic-fin rays 5 (I + 4). Caudal fin subtruncate, postero-dorsal and postero-ventral extremities rounded; total principal caudal-fin rays 13 (I + 11 + I), total dorsal procurrent rays 13 or 14 (xii-xiii + I), total ventral procurrent rays 10-12 (ix-xi + I). Vertebrae 41. Ribs 15. Single dorsal hypural plate, corresponding to hypurals 4 + 5 + 3; single ventral hypural plate corresponding to hypurals 1 and 2 and parhypural. Latero-sensory system Supraorbital sensory canal continuous, connected to infraorbital sensory canal posteriorly. Supraorbital sensory canal with 3 pores: s1, adjacent to medial margin of anterior nostril; s3, adjacent to medial margin of posterior nostril; and s6, on middle part of dorsal surface of head, in transverse line just posterior to orbit; pore s6 nearer midway between orbit and its paired homologous pore. Infraorbital sensory represented by single segment, with two pores: pore i10, adjacent to ventral margin of orbit, and pore i11, posterior to orbit. Postorbital canal with 2 pores: po1, in vertical line above posterior portion of interopercular patch of odontodes, and po2, in vertical line above posterior portion of opercular patch of odontodes. Lateral line of body short, with 2 pores, posterior-most pore in vertical just posterior to pectoral-fin base. Mesethmoidal region (Fig. 11B) Mesethmoid robust, its anterior margin about straight; mesethmoid cornu subtriangular, extremity slightly pointed; lateral flap on intersection between cornu and main bone axis, posteriorly extending parallel to lateral bone margin. Minute lateral projection on lateral ethmoid margin close to middle portion of sesamoid supraorbital. Antorbital thin, drop-shaped; sesamoid supraorbital flat, its length about twice and half antorbital length, with anterior lateral pointed expansion. Premaxilla sub-trapezoidal in dorsal view, longer than maxilla. Maxilla boomerang-shaped, slender, slightly curved. Autopalatine sub-rectangular in dorsal view, longer than wide, medial margin with deep notch, lateral margin nearly straight to slightly curved near posterolateral process; autopalatine posterolateral process subtriangular in dorsal view, short, its length shorter than osseus portion of autopalatine length excluding posterolateral process. Cheek region (Fig. 12B) Metapterygoid thin, subtriangular, large, its largest length slightly longer than horizontal length of quadrate excluding dorsal process; short process just anterior to articulatory cartilaginous block. Quadrate slender, dorsal process with constricted base, dorsoposterior margin in contact with from hyomandibula outgrowth. Hyomandibula long, with well-developed anterior outgrowth; middle portion of dorsal margin of hyomandibula slightly concave. Opercle broad, opercular odontode patch depth about two thirds of dorsal hyomandibula articular facet, with 12-15 odontodes; odontodes pointed, straight to slightly curved, arranged in irregular transverse rows; dorsal process of opercle short, extremity slightly posteriorly folded; opercular articular facet for hyomandibula with small, subtrapezoidal flap, articular facet for preopercle minute. Interopercle moderate, about two thirds hyomandibula length, anterior margin deeply concave, ventrally terminating in anteriorly directed prominent process; interopercular odontode patch with 23-25 odontodes; odontodes pointed, relatively short, arranged in irregular longitudinal rows. Preopercle compact, with short ventral flap and narrow postero-dorsal projection. Parurohyal (Fig. 13B) Robust, lateral process broad, posterior margin slightly convex, latero-posteriorly directed, extremity truncate; parurohyal head well-developed, with anterolateral paired process; middle foramen small, oval; posterior process relatively long, about six tenths of distance between anterior margin of parurohyal and anterior insertion of lateral process. Colouration in alcohol (Fig. 2) Flank, dorsum and head side pale yellow, with large black blotches irregularly arranged and often partially coalesced on flank, and small dark brown dots in more superficial skin layer, frequently overlapping black blotches. Venter and ventral part of head greyish white. Barbels black. Fins pale grey with black spots on basal portion.