Cambeva flavopicta, Costa & Feltrin & Katz, 2020

Costa, Wilson J. E. M., Feltrin, Caio R. M. & Katz, Axel M., 2020, A new species from subtropical Brazil and evidence of multiple pelvic fin losses in catfishes of the genus Cambeva (Siluriformes, Trichomycteridae), Zoosystematics and Evolution 96 (2), pp. 715-722 : 715

Cambeva flavopicta sp. nov. Figs 1 , 2 , Table 1

Type material.

Holotype. UFRJ 12665, 69.2 mm SL; Brazil: Estado de Santa Catarina: Município de Campos Novos: Rio Inferno Grande, Rio Canoas drainage, upper Rio Uruguai basin, 27°21'29"S, 51°01'02"W, about 910 m a.s.l.; CRM Feltrin, 22 May 2019.

Paratypes. All from Brazil: Estado de Santa Catarina: Município de Campos Novos: Rio Canoas drainage, upper Rio Uruguai basin: UFRJ 12234, 61, 31.5-73.6 mm SL; UFRJ 12664, 5, 38.2-47.9 mm SL (C&S); CICCAA 04776, 10, 34.5-53.4 mm SL; UFRJ 12235, 8, 27.7-61.7 mm SL; collected with holotype. UFRJ 12662, 10, 35.8-62.2 mm SL; UFRJ 12663, 3 (C&S), 38.7-43.4 mm SL; 27°22'05"S, 51°00'34"W; CRM Feltrin, 12 January 2019.

Diagnosis.

Cambeva flavopicta is distinguished from all other congeners, except C. pascuali and C. tropeiro , by the absence of pelvic fin and pelvic girdle (vs. pelvic fin and girdle present and well-developed). It is distinguished from both C. pascuali and C. tropeiro by having 6 pectoral-fin rays (vs. 5 in C. pascuali and 7 in C. tropeiro ), more dorsal procurrent caudal-fin rays (20-23 vs. 17-18 in C. pascuali and 14-15 in C. tropeiro ), more opercular odontodes (15-20 vs. 10-12 in C. pascuali and 12-14 in C. tropeiro ), more interopercular odontodes (25-30 vs. 11-12 in C. pascuali and 18-24 in C. tropeiro ) and colour pattern consisting of flank dark brownish-grey with two irregular horizontal rows of small pale yellow grey marks (vs. flank pale yellow with dark brown stripes or horizontal rows of spots in C. pascuali and flank yellowish-brown with dark brown spots irregularly arranged in C. tropeiro ). Cambeva flavopicta also differs from C. pascuali by the presence of the anterior section of the infra-orbital canal (vs. absence), more vertebrae (38-39 vs. 37) and more branchiostegal rays (9 vs. 7); and from C. tropeiro by having more ventral procurrent caudal-fin rays (16-17 vs. 10-11), the first pectoral-fin ray terminating in a short filament (vs. without a filament) and caudal fin rounded (vs. subtruncate).

Description.

Morphometric data are presented in Table 1 . Body moderately slender, subcylindrical and slightly depressed anteriorly, compressed posteriorly. Greatest body depth at midway between opercle and anal-fin origin. Dorsal profile of head and trunk slightly convex, approximately straight on caudal peduncle; ventral profile straight to slightly convex between lower jaw and end of anal-fin base, straight on caudal peduncle. Skin papillae minute. Anus and urogenital papilla in vertical through anterior portion of dorsal-fin base. Head trapezoidal in dorsal view. Anterior profile of snout convex in dorsal view. Eye small, dorsally positioned in head. Posterior nostril located slightly nearer anterior nostril than orbital rim. Tip of maxillary barbel reaching area between interopercular patch of odontodes and pectoral-fin base; rictal barbel reaching posterior part of interopercular patch of odontodes; tip of nasal barbel reaching area just anterior to opercular patch of odontodes. Mouth subterminal. Jaw teeth slightly pointed, few external-most teeth incisiform in larger specimens (above about 65 mm SL); premaxillary teeth about 45, slightly curved, arranged in 3 irregular rows; dentary teeth about 40-45, curved inside mouth, arranged in 3 irregular rows, more concentrated near dentary symphysis. Branchial membrane attached to isthmus only at its anterior point. Branchiostegal rays 9.

Dorsal and anal fins subtriangular; total dorsal-fin rays 11-12 (ii-iii + II-III + 6-7), total anal-fin rays 9 (ii + II + 5); anal-fin origin in vertical between middle and posterior half of dorsal-fin base, approximately between base of 3rd and 5th branched dorsal-fin ray. Dorsal-fin origin in vertical through centrum of 20th or 21st vertebra; anal-fin origin in vertical through centrum of 23rd or 24th vertebra. Pectoral fin subtriangular in dorsal view, posterior margin slightly convex, first pectoral-fin ray terminating in minute filament, about 10% or less of pectoral fin length without filament; total pectoral-fin rays 6 (I + 5). Pelvic fin and girdle absent. Posterior margin of caudal fin convex, upper and lower margins straight; total principal caudal-fin rays 13 (I + 11 + I), total dorsal procurrent rays 20-23 (ixx-xxii + I-II), total ventral procurrent rays 16-17 (xv-xvi + I). Vertebrae 38-39. Ribs 13 or 14. Two dorsal hypural plates, corresponding to hypurals 4 + 5 and 3, respectively; single ventral hypural plate corresponding to hypurals 1 and 2 and parhypural.

Latero-sensory system (Fig. 1).

Supraorbital sensory canal continuous, connected to posterior section of infraorbital canal posteriorly. Supraorbital sensory canal with 3 pores: s1, adjacent to medial margin of anterior nostril; s3, adjacent and just posterior to medial margin of posterior nostril; and s6, in transverse line through posterior half of orbit; pore s6 slightly nearer orbit than its paired homologous pore. Infra-orbital sensory canal arranged in 2 segments, each with two pores; anterior segment with pore i1, in transverse line through anterior nostril, and pore i3, in transverse line just anterior to posterior nostril; posterior segment with 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.

Osteology (Fig. 2).

Mesethmoid robust, its anterior margin nearly straight; mesethmoid cornu subtriangular in dorsal view, basal portion wide, abruptly narrowing distally, extremity pointed. Lacrimal-antorbital thin, drop-shaped; fronto-lacrimal tendon bone slender and with lateral process, sometimes membranous expansion, its length about one and half times or twice lacrimal-antorbital length. Premaxilla sub-rectangular in dorsal view, long, longer than distance between extremities of mesethmoid cornua. Maxilla boomerang-shaped, slender, about 80% maxilla length, slightly curved. Autopalatine subrectangular in dorsal view, compact, lateral and medial margins slightly concave, with small notch on middle part of medial margin; autopalatine posterolateral process almost indistinct. Metapterygoid thin, subtriangular, large, its largest length about equal horizontal length of quadrate excluding dorsal process; anteroventral portion of metapterygoid with short process just anterior to articulatory cartilaginous block. Quadrate slender, dorsal process with constricted base and antero-dorsal projection, dorsoposterior margin separated from hyomandibula outgrowth by interspace. Hyomandibula long, with well-developed anterior outgrowth; middle portion of dorsal margin of hyomandibula outgrowth with shallow concavity. Opercle slender, with 15-20 odontodes; odontodes pointed, nearly straight, arranged in irregular transverse rows; odontode patch depth about half interopercular odontode patch length; dorsal process of opercle short and pointed; ventral process of opercle moderate, about half opercle length. Interopercle moderate, about two thirds hyomandibula length, with 25-30 odontodes; odontodes pointed, arranged in irregular longitudinal rows; anterior margin of interopercle truncate; dorsal interopercular process with deep anterior concavity. Preopercle compact, with minute ventral flap. Parurohyal robust, lateral process latero-posteriorly directed, abruptly narrowing distally, tip sharply pointed; parurohyal head well-developed, with distinctive anterolateral paired process; middle foramen small and rounded; posterior process well-developed.

Colouration in alcohol (Fig. 1).

Flank dark brownish-grey, with two irregular horizontal rows of small pale yellow grey marks with varied shapes, mostly horizontally orientated, often horizontally coalesced on flank longitudinal midline, sometimes vertically coalesced on caudal peduncle; in some specimens, pale yellow marks restricted to small spots. Dorsum pale yellow with longitudinal row of rounded, longitudinally-elongated dark brown to black blotches and small pale brown dots. Venter yellowish-white, with brown chromatophores slightly concentrated on area just anterior to urogenital region and close to pectoral-fin base. Side and dorsal surface of head light yellowish-grey with irregularly-shaped dark brown to black spots; ventral surface of head yellowish-white, with brown chromatophores slightly concentrated anteriorly, to brown on lower jaw. Barbels brown. Opercle dark brown to black, interopercle yellowish-white with minute brown dots. Fins grey with small dark brown to black spots.

Distribution and habitat.

Cambeva flavopicta is only known from the upper Rio Inferno Grande and tributaries, Rio Canoas drainage, upper Rio Uruguai basin, southern Brazil (Fig. 3 ). The collecting sites were typical mountain rivers draining the Serra Geral, with fast flowing waters (Fig. 4 ). The species was found close to the riverbank, buried below marginal vegetation.

Etymology.

From the Latin, the name flavopicta (painted with yellow) refers to the characteristic colouration of this new species, with yellow marks over dark brown ground.

Figures

Figure 1. Cambeva flavopicta sp. nov., UFRJ 12665, holotype, 69.2 mm SL: A. Left lateral view; B. Dorsal view; C. Ventral view.

Figure 2. Osteological structures of Cambeva flavopicta sp. nov., UFRJ 12664, paratype, 47.9 mm SL: A. Mesethmoidal region and adjacent structures, left and middle portions, dorsal view; B. Left suspensorium and opercular series, lateral view; C. Parurohyal, ventral view. Arrow indicates the ventral process on the metapterygoid. Larger stippling represents cartilaginous areas.

Figure 3. Map of geographical distribution of Cambeva flavopicta sp. nov. (triangle), and type localities of C. diatropoporos (diamond), C. pascuali (pentagon), C. poikilos (star) and C. tropeiro (dot).

Figure 4. Rio Inferno Grande (upper Rio Uruguai basin, Santa Catarina, Brazil), at the exact point where the holotype and paratypes of Cambeva flavopicta sp. nov. were collected.