Cambeva orbitofrontalis, E. & Costa & M. & Feltrin & Katz, 2021

Costa, Wilson J. E. M., Feltrin, Caio R. M. & Katz, Axel M., 2021, 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, Zoosystema 43 (28), pp. 659-690 : 669-670

Cambeva orbitofrontalis n. sp.

( Figs 4 , 11D , 12D , 13D ; Table 4)

urn:lsid:zoobank.org:act:45F25566-C30E-43A4-8523-F77BEC7A5111

MATERIAL EXAMINED. — Holotype. Brazil • 1 ex., 56.2 mm SL; Santa Catarina State: Treviso Municipality: village of Santo Antônio: Cascata do Salto Branco , Rio Pio , Rio Mãe Luzia drainage, Rio Araranguá basin; 28°29’23”S, 49°31’22”W; about 385 m asl; C. R. M. Feltrin; 20.I.2021; UFRJ 6953 .

Paratypes. Brazil • 2 ex., 44.5-56.5 mm SL; collected with holotype; UFRJ 6954 • 3 ex. (C&S), 43.6-55.2 mm SL; collected with holotype; UFRJ 6955 • 2 ex., 43.6-45.5 mm SL; collected with holotype; CICCAA 04114 • 1 ex., 22.5 mm SL; same area as anterior; 28°29’32”S, 49°31’26”W; C. R. M. Feltrin; 29.IX.2018; UFRJ 6956 • 1 ex. (C&S), 47.3 mm SL; same area as anterior, 28°29’17”S, 49°30’45”W; about 300 m asl; C. R. M. Feltrin; 30.XI.2020; UFRJ 6957 • 2 ex., 21.8-29.7 mm SL; Siderópolis Municipality: village of Costão da Serra , Rio da Serra , about 100 from its confluence with Rio da Mina; 28°33’16”S, 49°34’53”W; about 230 m asl; C. R. M. Feltrin; 20.I.2021; UFRJ 6958 • 1 ex., 51.3 mm SL; Siderópolis Municipality: upper Rio São Bento, Costão da Serra ; 28°35’06”S, 49°33’54”W; about 160 m asl; C. R. M. Feltrin; 22.II.2021; UFRJ 6987 • 9 ex., 13.5-31.0 mm SL; Nova Veneza Municipality: stream tributary of Rio São Bento, São Bento Alto; 28°37’38”S, 49°34’11”W; about 125 m asl; C. R. M. Feltrin; 24.II.2021; UFRJ 6988 .

DIAGNOSIS. — Cambeva orbitofrontalis n. sp. differs from other species of the C. botuvera complex in having more ribs (16, vs 12 or 13 in C. botuvera and 14 in C. panthera n. sp.), seven branchiostegal rays (vs 8), fewer teeth in the premaxilla (36-38, vs 40-42 in C. botuvera and 44-46 in C. panthera n. sp.) and dentary (31-34, vs 40-42 in C. botuvera and 38-43 in C. panthera n. sp.), a rounded caudal fin (vs subtruncate) and a long sesamoid supraorbital, longer than the autopalatine (vs shorter). Also distinguished from C. botuvera in having a shorter pectoral fin (pectoral-fin length 7.6-9.1 % SL, vs 12.1-15.1 % SL) and a shorter space between orbit and anterior nostril (pre-orbital length 10.7-12.7 % of the head length, vs 13.6-16.7 %); and from C. panthera n. sp. in having fewer dorsal procurrent caudal-fin rays (18, vs 20-24), more vertebrae (39-40, vs 37), the dorsal-fin origin in a vertical through the centrum of the 21st vertebra (vs 18th or 19th), more opercular (13-15, vs 10 or 11) and interopercular odontodes (30-35, vs 23-25), a shorter caudal fin (caudal-fin length 13.0-15.2 % SL, vs 17.8-20.2 % SL), and shorter pelvic-fins (pelvic-fin length 7.6-9.1 % SL, vs 9.7-12.6 % SL).

DISTRIBUTION. — Cambeva orbitofrontalis n. sp. occurs in the eastern forested slope. It is found in the Rio Araranguá basin, in altitudes between about 130 and 390 m ( Fig. 14 ).

ETYMOLOGY. — From the Latin orbita (orbit, referring to the eye socket) and frontalis (frontal), in allusion to the unique long sesamoid supraorbital bone, with posterior extremity firmly attached to the frontal bone.

DESCRIPTION

General morphology

Morphometric data in Table 4. 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 portion of interopercular patch of odontodes; tip of rictal barbel reaching anterior part of interopercular patch of odontodes; tip of nasal barbel slightly posteriorly surpassing orbit. Mouth subterminal. Jaw teeth slightly pointed to incisiform in outer areas, slightly curved, irregularly arranged, 36-38 in premaxilla, 31-34 in dentary. Branchial membrane attached to isthmus only at its anterior point. Branchiostegal rays 7. Cranial fontanels present, posterior fontanel long, anteriorly extending between frontals to reach transverse line close to lateral sphenotic process. Dorsal fin short, subrectangular, anal fin subtriangular, distal margin slightly convex in both; total dorsal-fin rays 11 (ii + I-II + 7-8), total anal-fin rays 9 (ii + II + 5); anal-fin origin in vertical through last third of dorsal-fin base. Dorsal-fin origin in vertical through centrum of 21st vertebra; anal-fin origin in vertical through centrum of 24th or 25th 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 anterior to dorsalfin base; pelvic-fin bases medially in close proximity; total pelvic-fin rays 5 (I + 4). Caudal fin rounded; total principal caudal-fin rays 13 (I + 11 + I), total dorsal procurrent rays 18 (xvii + I), total ventral procurrent rays 13 (xii + I). Vertebrae 39-40. Ribs 16. 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

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 orbit than its paired homologous pore. Infraorbital sensory canal 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. 11D )

Mesethmoid robust, its anterior margin about straight; mesethmoid cornu subtriangular, extremity pointed; narrow 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, often absent. Antorbital thin, dropshaped; sesamoid supraorbital slender, long and slightly curved, its length about three and half times antorbital length, without lateral projections, its posterior portion firmly attached to neurocranium. Premaxilla sub-trapezoidal in dorsal view, slightly laterally narrowing, longer than maxilla. Maxilla boomerangshaped, slender, curved. Autopalatine sub-rectangular in dorsal view, moderate in width, slightly longer than wide when excluding posterolateral process, medial margin sinuous, lateral margin nearly straight to slightly curved near posterolateral process; autopalatine posterolateral process subtriangular in dorsal view, with sharp extremity, short, its length shorter than osseus portion of autopalatine length excluding posterolateral process.

Cheek region ( Fig. 12D )

Metapterygoid thin, subtriangular, large, its largest length slightly longer than horizontal length of quadrate excluding dorsal process; minute projection on anteroventral bone margin, close to articulatory cartilage block. Quadrate slender, dorsal process with constricted base, dorsoposterior margin in contact with from hyomandibula outgrowth; small process close and anterior to cartilage articulating quadrate and metapterygoid. Hyomandibula long, with well-developed anterior outgrowth; deep notch on dorsal margin of hyomandibula outgrowth. Opercle slender, abruptly widening on odontode patch, its depth about three fifths of dorsal hyomandibula articular facet, 13-15 odontodes; odontodes pointed, straight to slightly curved, arranged in irregular transverse rows; dorsal process of opercle short and truncate; opercular articular facet for hyomandibula with small, rounded flap, articular facet for preopercle indistinct. Interopercle moderate, about two thirds hyomandibula length, anterior margin slightly concave; interopercular odontode patch with 30-35 pointed odontodes, arranged in irregular longitudinal rows. Preopercle compact, with short ventral flap.

Parurohyal ( Fig. 13D )

Robust, lateral process sub-triangular, weakly curved, lateroposteriorly directed, extremity pointed, posterior margin slightly sinuous; parurohyal head well-developed, with anterolateral paired process; middle foramen small, round; posterior process relatively long, about half distance between anterior margin of parurohyal and anterior insertion of lateral process.

Colouration in alcohol ( Fig. 4 )

Flank, dorsum and head side pale yellowish grey, with small, rounded dark grey spots, larger on dorsal portion of flank; spots irregularly arranged, except forming horizontal row on longitudinal midlateral line of flank. Venter and ventral part of flank yellowish white. Barbels dark grey. Fins hyaline with grey rays on basal portion.

Figures

FIG. 4. — Cambeva orbitofrontalis n. sp., UFRJ 6953, holotype, 56.2 mm SL: A, left lateral view; B, dorsal view; C, ventral view.

FIG. 11. — Mesethmoidal region and adjacent structures, left and middle portions, dorsal view: A, Cambeva diffusa n. sp.; B, Cambeva pericoh n. sp.; C, Cambeva imaruhy n. sp.; D, Cambeva orbitofrontalis n. sp.; E, Cambeva panthera n. sp.; F, Cambeva grisea n. sp.; G, Cambeva duplimaculata n. sp.; H, Cambeva longipalata n. sp.; I, Cambeva notabilis n. sp.; J, Cambeva tropeira; K, Cambeva urubici n. sp. Larger stippling represents cartilaginous areas.

FIG. 12. — Left suspensorium and opercular series, lateral view: A, Cambeva diffusa n. sp.; B, Cambeva pericoh n. sp.; C, Cambeva imaruhy n. sp.; D, Cambeva orbitofrontalis n. sp.; E, Cambeva panthera n. sp.; F, Cambeva grisea n. sp.; G, Cambeva duplimaculata n. sp.; H, Cambeva longipalata n. sp.; I, Cambeva notabilis n. sp.; J, Cambeva urubici n. sp. Abbreviations of structures indicated by arrows are: iac, interopercular anterior concavity; ppe, preopercular postero-dorsal expansion; odc, opercular dorsal constriction; odp, opercular dorsal process; ppp, parurohyal posterior process.Larger stippling represents cartilaginous areas.

FIG. 13. — Urohyal, ventral view.A, Cambeva diffusa n. sp.; B, Cambeva pericoh n. sp.; C, Cambeva imaruhy n. sp.; D, Cambeva orbitofrontalis n. sp.; E, Cambeva panthera n. sp.; F, Cambeva grisea n. sp.; G, Cambeva duplimaculata n. sp.; H, Cambeva longipalata n. sp.; I, Cambeva notabilis n. sp.; J, Cambeva urubici n. sp.

FIG. 14. — Map of geographical distribution of Cambeva Katz, Barbosa, Mattos & Costa, 2018 in the southeastern nucleus of the Serra Geral (SESG), southern Brazil.