Cambeva luteoreticulata Costa, Feltrin & Katz, 2024

Costa, Wilson J. E. M., Feltrin, Caio R. M., Mattos, José Leonardo O. & Katz, Axel M., 2024, Top mountain areas of subtropical southern Brazil sheltering four new small-ranged catfishes (Siluriformes, Trichomycteridae): relationships and taxonomy, Evolutionary Systematics 8 (2), pp. 199-218 : 199-218

Cambeva luteoreticulata Costa, Feltrin & Katz sp. nov.

Figs 4 G – I , 8 , 9 , Table 5

Type material.

Holotype. Brazil • 81.6 mm SL; Santa Catarina State: Matos Costa Municipality: village of Colônia Cerne: stream tributary of Rio Liso, itself a tributary of Rio Pintado, Rio Iguaçu drainage, Rio Paraná basin ; 26 ° 24 ' 25 " S, 51 ° 00 ' 45 " W; about 1,015 m asl; 1 Apr. 2023; C. R. M. Feltrin and L. Sebben, leg.; UFRJ 14068 .

Paratypes. Brazil • 7 ex. 25.2–70.8 mm SL; same data as holotype; UFRJ 13562 . • 3 ex. (DNA), 22.7–42.6 mm SL; same data as holotype; UFRJ 13563 . • 15 ex., 27.6–77.2 mm SL; same locality and collectors as holotype; 1 Jul. 2023; UFRJ 13828 . • 4 ex. 33.7–75.9 mm SL; same locality and collectors as holotype; 1 Jul. 2023; CICCAA 08268 . • 4 ex. (C & S), 38.2–65.9 mm SL; same locality and collectors as holotype; 1 Jul. 2023; UFRJ 14069 .

Diagnosis.

Cambeva luteoreticulata differs from all other congeners by its unique rounded, stapula-shaped caudal fin in specimens above about 40 mm SL (Fig. 8 A ). Cambeva luteoreticulata is also distinguished from all other congeners of the Cambeva beta-clade, except Cambeva chrysornata Costa, Feltrin, Mattos, Dalcin, Abilhoa & Katz, 2023 and C. papillifera , by having short barbels, with the nasal barbel not reaching the orbit in specimens above 60 mm SL and maxillary and rictal barbels not reaching the interopercular patch of odontodes. Cambeva luteoreticulata also differs from C. chrysornata and C. papillifera by the absence of the anterior segment of the infraorbital series (vs. presence), from C. chrysornata by having more procurrent caudal-fin rays (21 or 22 dorsal and 15 or 16 ventral, vs. 16 or 17 and 11 or 12, respectively) and fewer opercular odontodes (10–12 vs. 18), and from C. papillifera by the absence of hypertrophied papillae on the head surface (vs. presence) and narrow nasal barbel (vs. broad laminar, ribbon-shaped). Cambeva luteoreticulata is also distinguished from all other congeners by a unique pattern of ontogenetic colouration change consisting of flank pale yellow with irregularly shaped and arranged, dark brown to black blotches in specimens below about 40 mm SL (Fig. 9 A ), becoming dark brown, with small, irregularly shaped pale yellow marks forming reticulate pattern in larger specimens (Fig. 8 A ). Cambeva luteoreticulata also differs from all the remaining congeners from the Rio Iguaçu drainage by the following combination of character states: seven pectoral-fin rays (vs. eight in C. castroi , C. melanoptera , C. crassicaudata , C. stawiarski ; and six in C. galactica , C. naipi , and C. taroba ); absence of the anterior infraorbital (vs. presence in C. galactica , C. naipi , C. plumbea , and C. taroba ); posterior margin of the caudal fin convex (vs. about straight in C. crassicaudata , C. davisi , C. galactica , C. melanoptera , C. papillifera , C. piraquara , C. plumbea , C. igobi ; straight to slightly concave in C. stawiarski ; bilobed in C. crassicaudata ; and emarginate in Cambeva cauim ); absence of pectoral-fin filament (vs. presence a well-developed filament in C. taroba and a rudimentary filament in C. davisi and C. piraquara ); nine or 10 opercular odontodes (vs. broad, with 17 or 18 in C. mboycy ; 15 or 16 in C. davisi ; seven or eight in C. taroba ); 29–32 interopercular odontodes (vs. 12 or 13 in C. naipi ; 17–21 in C. mboycy and C. taroba ); 25 dorsal procurrent caudal-fin rays (vs. 15–17 in C. castroi and C. melanoptera ; 18 or 19 in C. naipi ;; 30 or 31 in C. cauim ); 15 or 16 ventral procurrent caudal-fin rays (vs. 21–23 in C. taroba ); dorsal-fin origin at a vertical through the centrum of the 21 st or 22 nd vertebra (vs. 19 th or 20 th in C. crassicaudata , C. mboycy , and C. stawiarski ); larger jaw teeth incisiform, teeth arranged in rows (vs. pointed to slight rounded, irregularly arranged in all species, except C. davisi ); and 38–40 vertebrae (36 in C. taroba ). Molecular diagnosis: 17 nucleotide substitutions, five of them unique among taxa analysed * and one unique for the Cambeva beta-clade **: COX 1 252 (A → G), COX 1 564 (A → C) *, COX 1 648 (C → T) *, COX 1 678 (A → G), CYTB 123 (C → T), CYTB 206 (G → C) *, CYTB 294 (C → T) *, CYTB 474 (G → A), CYTB 495 (G → A), CYTB 636 (C → T) *, CYTB 675 (T → C), CYTB 696 (A → G), CYTB 696 (A → G), CYTB 879 (A → G) **, CYTB 988 (G → A), CYTB 996 (A → G), CYTB 1038 (C → T). COX 1 p-distances among congeners of the Cambeva beta-clade ranging from 1.5 ( Cambeva atrobrunnea Costa, Feltrin & Katz , sp. nov. and Cambeva rotundipinna Costa, Feltrin & Katz , sp. nov.) and 4.3.

Description.

Morphometric data appear in Table 5 .

Head morphology. Barbels short. Nasal barbel reaching area anterior to orbit in specimens above 60 mm SL, between orbit and area just posterior to it in smaller specimens, and maxillary and rictal barbels reaching area just anterior to interopercular patch of odontodes. Jaw teeth variable in shape, smaller teeth slightly pointed, larger teeth incisiform with slightly rounded tip, arranged in three series. Premaxillary outer row with 14 or 15 teeth, middle row with 16 or 17 teeth, and inner row with 18 teeth; total premaxillary teeth 49. Dentary outer row with 10 or 11 teeth, middle row with 14 or 15 teeth, and inner row with 17–20 teeth; total dentary teeth 42–45. Opercular and interopercular odontodes pointed, about straight. Opercular odontodes 10–12; interopercular odontodes 29–33.

Fin morphology. Dorsal and anal fins subtriangular, distal margin slightly convex. Total dorsal-fin rays 11 (ii + II + 7), total anal-fin rays 9 (ii + II + 5). Anal-fin origin at vertical through posterior portion of dorsal-fin base, at base of 5 th branched dorsal-fin ray. Pectoral fin rounded in dorsal view, first pectoral-fin ray shorter than second ray, not forming terminal filament. Total pectoral-fin rays 7 (I + 6). Pelvic fin rounded, its tip reaching vertical through dorsal-fin origin. Total pelvic-fin rays 5 (I + 4). Caudal fin short, rounded, forming spatula-shaped tail in specimens above about 40 mm SL. Total principal caudal-fin rays 13 (I + 11 + I), total dorsal procurrent rays 21 or 22 (xx-xxi + I), total ventral procurrent rays 15 or 16 (xiv – xv + I).

Osteology (Fig. 4 G – I ). Mesethmoid distinctively broader anteriorly, with lateral expansion in area just anterior to lateral ethmoid, anterior mesethmoid margin about straight to slightly convex. Mesethmoid cornu extremity rounded. Lateral ethmoid with small lateral projection immediately posterior to articular facet for autopalatine. Lacrimal thin, elliptical. Sesamoid supraorbital about two times and half longer than lacrimal, without lateral expansions, its width about equal to lacrimal width. Premaxilla long, laterally narrowing, slightly curved. Maxilla slender, without posterior process, slightly curved, its length about four fifths of premaxilla. Autopalatine sub-trapezoidal in dorsal view, medial margin sinuous, lateral margin weakly concave. Autopalatine postero-lateral process triangular, short, its length about half autopalatine length.

Metapterygoid sub-rectangular, deeper than long, relatively large, its surface greater than quadrate lateral surface. Quadrate with deep anterior constriction at dorsal process base. Hyomandibula long, anterior outgrowth horizontal length slightly longer than largest horizontal metapterygoid length; dorsal margin of hyomandibula outgrowth straight anteriorly, with pronounced U-shaped concavity posteriorly. Opercle elongate, longer than interopercle. Opercular odontode patch slender, its depth about half hyomandibula articular facet length. Dorsal process of opercle short, subtriangular, its extremity rounded. Opercular articular facet for hyomandibula with dorsal, broad, rounded laminar projection, articular facet for preopercle rudimentary. Interopercle moderate in length, interopercular odontode patch length about equal hyomandibula outgrowth length. Preopercle slender, with minute ventral projection.

Parurohyal robust, lateral process subtriangular, slightly curved posteriorly, with pointed tip. Parurohyal head with prominent anterolateral paired process. Parurohyal middle foramen relatively large, oval. Parurohyal posterior process moderate in length, about three fifths of distance between anterior margin of parurohyal and anterior insertion of posterior process. Branchiostegal rays 9 or 10. Vertebrae 38–40. Ribs 14–16. Dorsal-fin origin at vertical through centrum of 21 st or 22 nd vertebra; anal-fin origin at vertical through centrum of 25 th or 26 th vertebra. Two dorsal and single ventral hypural plate.

Colouration in alcohol. In adult specimens (Fig. 8 A ), flank, dorsum and head side dark brown, with small, irregularly shaped, irregularly arranged, pale yellow marks forming reticulate pattern. Nasal and maxillary barbels brown, rictal barbel grey. Venter and ventral surface of head yellowish white. Fins pale grey with black spots on basal region, dark brown dots in middle region. In juvenile specimens below about 40 mm SL (Fig. 9 A ), flank, dorsum and head side pale yellow with large dark brown to black blotches, more concentrated and sometimes forming longitudinal stripes in area between dorsum and flank.

Distribution.

Cambeva luteoreticulata is known from a single locality in a stream tributary of the Rio Liso, Rio Iguaçu drainage, Rio Paraná basin, at about 1,015 m asl (Fig. 5 ).

Etymology.

From the Latin luteus (saffron yellow) and reticulata (reticulated), in reference to the flank colour pattern of adult specimens.

Figures

Figure 4. Osteological structures of: A – C. Cambeva galactica Costa, Feltrin & Katz, sp. nov.; D – F. Cambeva atrobrunnea Costa, Feltrin & Katz, sp. nov.; G – I. Cambeva luteoreticulata Costa, Feltrin & Katz, sp. nov., and J – L. Cambeva rotundipinna Costa, Feltrin & Katz, sp. nov. A, D, G, J. Mesethmoidal region and adjacent structures, left and middle portions, dorsal view; B, E, H, K. Left jaw suspensorium and opercular series, lateral view. C, F, I, L. Parurohyal, ventral view. Abbreviation of structure indicated by arrow: aes, anteromedial expansion of sesamoid supraorbital. Larger stippling represents cartilaginous areas.

Figure 5. Geographical distribution of four new species of Cambeva from the Rio Iguaçu drainage, Serra do Espigão, southern Brazil: 1. Cambeva galactica Costa, Feltrin & Katz, sp. nov.; 2. Cambeva atrobrunnea Costa, Feltrin & Katz, sp. nov.; 3. Cambeva luteoreticulata Costa, Feltrin & Katz, sp. nov.; 4. Cambeva rotundipinna Costa, Feltrin & Katz, sp. nov.

Figure 8. Cambeva luteoreticulata Costa, Feltrin & Katz, sp. nov., holotype, UFRJ 14068, 81.6 mm SL. A. Lateral view; B. Dorsal view; C. Ventral view.

Figure 9. Cambeva luteoreticulata Costa, Feltrin & Katz, sp. nov., paratype, UFRJ 13562, 33.1 mm SL. A. Lateral view; B. Dorsal view; C. Ventral view.