Cambeva imaruhy, 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 : 667-669

Cambeva imaruhy n. sp.

( Figs 3 , 11C , 12C , 13C ; Table 3)

urn:lsid:zoobank.org:act:15E30D5C-5407-4905-A2F6-BA2F3FF76730

MATERIAL EXAMINED. — Holotype. Brazil • 1 ex., 60.6 mm SL; Santa Catarina state: Orleans municipality: Rio Minador, Rio Laranjeiras drainage, village of Brusque do Sul ; 28°14’33”S, 49°24’13”W; about 250 m asl; 26.I.2021; UFRJ 6939 .

Paratypes. Brazil • 6 ex., 23.8-36.7 mm SL; collected with holotype; UFRJ 6964 • 1 ex., 55.8 mm SL; upper Rio Laranjeiras , Rio Tubarão basin, Caminho dos Tropeiros da Serra do Imaruí; 28°13’30”S, 49°29’06”W; about 440 m asl; C. R. M. Feltrin; 9.III. 2020 • 7 ex., 25.6-40.8 mm SL; Lauro Muller municipality: upper Rio Rocinha, Novo Horizonte; 28°23’42”S, 49°28’06”W; about 315 m asl; C. R. M. Feltrin; 22.X.2020; UFRJ 6940 • 5 ex., 30.0- 36.4 mm SL; same data as UFRJ 6940; CICCAA 04113 • 5 ex., 32.3-38.8 mm SL (C&S); same data as UFRJ 6940; UFRJ 6941 .

ADDITIONAL MATERIAL (NON- TYPE SPECIMENS). — Brazil • 1 ex.; Santa Catarina State: Grão Pará Municipality: Rio Braço Esquerdo subdrainage, Rio Braço do Norte drainage, Rio Tubarão basin; 28°08’37”S, 49°23’25”W; about 450 m asl; C. R. M. Feltrin; 17.II.2021; UFRJ 6959 • 4 ex.; same area as UFRJ 6959; 28°08’29”S, 49°23’37”W; about 460 m asl; C. R. M. Feltrin; 17.II.2021; UFRJ 6960 • 2 ex. (C&S); same data as precedent; UFRJ 6961 .

DIAGNOSIS. — Cambeva imaruhy n. sp. differs from C. barbosae and C. cubataonis in having 15-17 ribs (vs 11-13) and posterior margin of the parurohyal lateral process concave ( Fig. 13C ; vs straight, Costa et al. 2021a: fig. 4C); from C. barbosae in having seven pectoral-fin rays (vs six), fewer interopercular odontodes (19-22 vs 30-36), and fewer jaw teeth (32-35 in the premaxilla, 26-30 in the dentary, vs 40-52 and 42-45, respectively), and from C. cubataonis in having 38-40 vertebrae (vs 36-37), the dorsal-fin origin in a vertical through the centrum of the 20th or 21st vertebra (vs 18th vertebra), and the anal-fin origin in a vertical through the centrum of the 24th or 25th vertebra (vs 23rd vertebra), as well as a different colour pattern, consisting of a hight concentration of small rounded dark grey spots on the flank ( Fig. 3 ; vs large brownish spots on the dorsal portion of the flank, Katz & Barbosa 2014: figs 1-2).

DISTRIBUTION. — Cambeva imaruhy n. sp. occurs in the eastern forested slope. It is only known from the Rio Tubarão basin, in altitudes between about 250 and 440 m asl ( Fig. 14 ).

ETYMOLOGY. — The name imaruhy is an allusion to the occurrence of the species in the Caminho dos Tropeiros da Serra do Imaruí (formerly Imaruhy), an old track used to cross the Serra Geral during the 19th century, in a land previously inhabited by the Xokleng people. The word imaruhy is possibly derived from the Tupi-Guarani, meaning water mosquito.

DESCRIPTION

General morphology

Morphometric data in Table 3. Body slender, subcylindrical and slightly depressed anteriorly, 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 portion of dorsal-fin base. Head trapezoidal in dorsal view, anterior profile of snout convex. Eye small, dorsally positioned in head, on anterior half of head. Posterior nostril located nearer anterior nostril than orbital rim. Tip of maxillary barbel reaching between posterior portion of interopercular patch of odontodes and middle portion of pectoral-fin base; tip of rictal barbel reaching between middle portion of interopercular patch of odontodes and pectoral-fin base; tip of nasal barbel reaching opercular patch of odontodes. Mouth subterminal. Jaw teeth pointed, slightly curved, irregularly arranged; premaxillary teeth 32-35, dentary teeth 26-30. Branchial membrane attached to isthmus only at its anterior point. Branchiostegal rays 7 or 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 11-12 (iii + II + 7-8), total anal-fin rays 9 (ii + II + 5); anal-fin origin in vertical through posterior half of dorsal-fin base. Dorsal-fin origin in vertical through centrum of 20th or 21st vertebra; anal-fin origin in vertical through centrum of 24th or 25th vertebra. Pectoral fin subtriangular in dorsal view, posterior margin slightly convex, tip of first pectoral-fin ray slightly projecting beyond fin, forming minute filament; total pectoral-fin rays 7 (I + 6). Pelvic fin subtruncate, its extremity in vertical through anterior portion of dorsal-fin base; pelvic-fin bases medially separated by minute interspace; total pelvic-fin rays 5 (I + 4). Caudal fin subtruncate, postero-dorsal and posteroventral extremities rounded; total principal caudal-fin rays 13 (I + 11 + I), total dorsal procurrent rays 20-21 (xix-xx + I), total ventral procurrent rays 12-15 (xi-xiv + I). Vertebrae 38-40. Ribs 15-17. Two dorsal hypural plates, corresponding to hypurals 4 + 5 and 3, respectively, sometimes coalesced to form single plate; single ventral hypural plate corresponding to hypurals 1 and 2 and parhypural.

Latero-sensory system

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 nearer orbit than its paired homologous pore. Single infraorbital sensory canal segment, with two pores, corresponding to pore i10, adjacent to ventral margin of orbit, and pore i11, posterior to orbit; anterior segment of infraorbital canal absent. 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. 11C )

Mesethmoid relatively thin, its anterior margin slightly concave; mesethmoid cornu narrow, extremity slightly pointed. No lateral projection on lateral ethmoid margin. Antorbital thin, drop-shaped; sesamoid supraorbital very slender, rod-shaped, without processes, its length about three times antorbital length. Premaxilla sub-trapezoidal in dorsal view, laterally narrowing, moderate in length, slightly longer than maxilla. Maxilla boomerang-shaped, slender, slightly curved. Autopalatine sub-rectangular in dorsal view, medial margin sinuous, lateral margin slightly concave; autopalatine posterolateral process well-developed, narrow, its length about two thirds autopalatine length excluding posterolateral.

Cheek region ( Fig. 12C )

Metapterygoid thin, subtriangular, large, its largest length slightly shorter than horizontal length of quadrate excluding dorsal process; minute marginal process just posterior to cartilage articulating metapterygoid and quadrate. Quadrate slender, dorsal process with constricted base, dorsoposterior margin separated from hyomandibula outgrowth by small interspace. Hyomandibula long, with well-developed anterior outgrowth; middle portion of dorsal margin of hyomandibula concave. Opercle compact, opercular odontode patch depth about equal length of dorsal hyomandibula articular facet, with 15-17 odontodes; odontodes pointed, nearly straight to slightly curved, arranged in irregular transverse rows; dorsal process of opercle short and pointed; opercular articular facet for hyomandibula with prominent flap, articular facet for preopercle well-developed, subtriangular, in close proximity to articular facet for hyomandibula. Interopercle moderate, about three fifths of thirds hyomandibula length, with 19-22 odontodes; odontodes pointed, arranged in irregular longitudinal rows. Preopercle compact, with short ventral flap.

Parurohyal ( Fig. 13C )

Parurohyal robust, lateral process sub-triangular, slightly curved, latero-posteriorly directed, extremity pointed; parurohyal head well-developed, with distinctive anterolateral paired process; middle foramen broad, oval; posterior process long, about half length distance between anterior margin of parurohyal and anterior insertion of posterior process.

Colouration in alcohol ( Fig. 3 )

Flank, dorsum and head side pale yellowish brown. Dorsum and flank with hight concentration of small rounded dark grey spots, variable in size in different species, usually smaller than orbit, sometimes three or four times orbit, rarely very small almost imperceptible, often darker on flank midline and on procurrent caudal-fin rays, sometimes inconspicuous below midline. Dark pigment concentrated between anterior nostril and orbit, and on nasal barbel base. Venter and ventral surface of head light yellowish white. Unpaired fins hyaline with finely dark brown pigmented rays. Paired fins whiteish hyaline.

Figures

FIG. 3. — Cambeva imaruhy n. sp., UFRJ 6939, holotype, 60.6 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.