Trichomycterus (Cryptocambeva) berthalutzae, Costa & Barbosa & Katz, 2024

Costa, Wilson J. E. M., Barbosa, Maria Anaïs & Katz, Axel M., 2024, Two new species of Trichomycterus (Siluriformes: Trichomycteridae) from the Rio Itabapoana Basin, south-eastern Brazil, European Journal of Taxonomy 970, pp. 122-137 : 125-129

Trichomycterus (Cryptocambeva) berthalutzae sp. nov.

urn:lsid:zoobank.org:act:1C096988-F641-43DB-8EFC-B3431F75FD13

Figs 1 , 2A–C , 3 , Table 1

Trichomycterus sp. – Vilardo et al. 2023: fig. 3 (phylogenetic relationships).

Diagnosis

Trichomycterus (Cryptocambeva) berthalutzae sp. nov. is distinguished from all other species of the NMM-clade of Cryptocambeva by having a shorter nasal barbel, its tip not reaching the opercular patch of odontodes (vs reaching or surpassing it), and a sinuous medial margin of the autopalatine ( Fig. 2A , vs about straight or slightly concave). Trichomycterus (Cryptocambeva) berthalutzae is also distinguished from T. brunoi and T. fuliginosus by having a minute pectoral-fin filament, its length about 10% or less of the pectoral-fin length (vs about 20–25%), more dorsal procurrent caudal-fin rays (20 or 21, vs 16–19), flank with sparse dark brown dots that are separated among themselves by large interspaces (vs dots highly overlapped), the presence of a lateral expansion on the sesamoid supraorbital ( Fig. 2A ; vs absence), and absence of an elongate expansion on the posteroventral margin of the metapterygoid ( Fig. 2B , vs presence, Barbosa & Costa 2010: figs 1, 4); and from T. argos by having fewer opercular odontodes (12–15 vs 16–22) and the absence of a vertical zone of dark chromatophores on the caudal-fin base, forming a distinctive bar (vs presence).

Etymology

The specific epithet ‘ berthalutzae ’ honours the Brazilian herpetologist Bertha Maria Júlia Lutz (1894– 1976), professor emeritus at Federal University of Rio de Janeiro, who between 1919 and 1964 worked at the National Museum of that institution, describing several species of anurans from the mountains of the Atlantic Forest and other locations. She was also an important feminist activist, being the main actor in guaranteeing women’s right to vote during the United Nations Conference in San Francisco, 1945.

Type material

Holotype BRAZIL • 78.1 mm SL; Espírito Santo State, Mimoso do Sul Municipality, Rio Alto Pratinha , tributary of the Rio Muqui do Sul , Rio Itabapoana Basin; 21°03′51″ S, 41°18′13″ W; ca 205 m a.s.l.; 27 Feb. 2007; M.A. Barbosa, J.L.O. Mattos and E.M. Ribeiro leg; UFRJ 12930 .

Paratypes BRAZIL • 3 ex., 19.0– 35.6 mm SL; same data as for holotype; UFRJ 7546 • 3 ex., 32.0– 96.1 mm SL; same data as for holotype; CICCAA 07749 • 2 ex. (C&S), 31.2–44.5 mm SL; same data as for holotype; UFRJ 12932 . • 9 ex., 21.1–46.2 mm SL; same data as for holotype; 19 Sep. 2022; A.M. Katz and P.J. Vilardo leg; UFRJ 13252 • 1 ex. ( C & S), 45.8 mm SL; same data as for preceding; UFRJ 13650 .

Description

GENERAL MORPHOLOGY. Morphometric data see Table 1 . Body moderately slender, head and trunk with dorsal and ventral profiles slightly convex, dorsal and ventral profiles of caudal peduncle nearly straight, greatest body depth at vertical just anterior to pelvic-fin base. Trunk subcylindrical anteriorly, compressed posteriorly. Anus and urogenital papilla at vertical just posterior to dorsal-fin origin. Head subtrapezoidal in dorsal view, snout profile rounded. Eye relatively small, dorsally positioned in head. Posterior nostril located nearer anterior nostril than orbital rim. Tip of maxillary and rictal barbels reaching between anterior and posterior regions of interopercular patch of odontodes, tip of nasal barbel reaching about midway between orbit and opercle or slightly before. Mouth subterminal. Jaw teeth pointed, slightly curved, arranged in irregular rows. Premaxillary teeth 47–60, dentary teeth 40–43. Odontodes conical. Opercular odontodes 12–15, interopercular odontodes 34–42. Branchiostegal rays 8.

FINS. Dorsal and anal fins subtriangular, anterior and posterior margins slightly convex; longest ray longer than fin base. Total dorsal-fin rays 10–11 (ii + II + 6–7), total anal-fin rays 9 (ii + II + 5); anal-fin origin at vertical shortly posterior to middle of dorsal-fin base, through base of 4 th branched ray. Dorsal-fin origin at vertical through centrum of 20 th vertebra; anal-fin origin at vertical between centrum of 22 nd or 23 rd vertebra. Pectoral fin subtriangular in dorsal view, posterior margin slightly convex, first pectoral-fin ray terminating in filament, its length about 10% or less of pectoral-fin length without filament. Total pectoral-fin rays 7 (I + 6). Pelvic fin rounded, its posterior extremity covering urogenital papilla, at vertical through anterior half of dorsal-fin base. Pelvic-fin bases medially separated by minute interspace. Total pelvic-fin rays 5 (I + 4). Caudal fin slightly rounded, dorso-ventrally symmetrical. Total principal caudal-fin rays 13 (I + 11 + I), total dorsal procurrent rays 20 or 21 (xix–xx + I), total ventral procurrent rays 14 or 15 (xiii–xiv + I).

LATERO-SENSORY SYSTEM. Supraorbital canal, posterior section of infraorbital canal and postorbital canal continuous. Supraorbital sensory canal with 3 paired pores: s1, adjacent to medial margin of anterior nostril; s3, adjacent and just posterior to medial margin of posterior nostril, and s6, at transverse line through posterior half of orbit; s6 pore nearer to its symmetrical homologous s6 pore than to orbit, sometimes at close proximity. Infraorbital sensory canal with 2 segments. Anterior infraorbital canal with 2 pores: i1, at transverse line through anterior nostril, and i3, at transverse line just anterior to posterior nostril. Posterior infraorbital canal with two pores: i10, adjacent to ventral margin of orbit, and i11, posterior to orbit. Postorbital canal with 2 pores: po1, at vertical line above posterior portion of interopercular patch of odontodes, and po2, at vertical line above posterior portion of opercular patch of odontodes. Lateral line of trunk with 2 pores just posterior to head.

OSTEOLOGY ( Fig. 2A–C ). Anterior margin of mesethmoid nearly straight to slightly convex, mesethmoid cornu narrow. Lacrimal narrow and flat, its largest length about 3 /5 of sesamoid supraorbital largest length. Sesamoid supraorbital flat, its largest length smaller than largest maxilla length, with distinctive lateral projection. Premaxilla sub-rectangular in dorsal view, slightly tapering laterally. Maxilla boomerang-shaped, slender, shorter than premaxilla, with minute posterior process. Autopalatine sub-rectangular in dorsal view when excluding posterolateral process, lateral margin about straight, medial margin sinuous. Shortest autopalatine width about half autopalatine length. Latero-posterior process of autopalatine subtriangular, its length about equal shortest autopalatine width. Metapterygoid subtriangular, deeper than long, with distinctive postero-dorsal projection. Quadrate robust, dorsoposterior outgrowth in close proximity to hyomandibular outgrowth. Hyomandibula long, anterior outgrow deep, with small concavity on dorsal margin. Opercle slender, depth of opercular odontode patch about half dorsal articular facet of hyomandibula, dorsal process of opercle short, subtriangular. Interopercle long, about three fourths of hyomandibula length. Preopercle compact, slender, with small ventral expansion. Parurohyal robust, lateral process relatively elongate, pointed, slightly curved. Parurohyal head well-developed, with prominent anterolateral paired process. Middle parurohyal foramen oval, its largest length about equal to posterior parurohyal process. Posterior parurohyal process about half distance between anterior margin of parurohyal and anterior insertion of posterior process. Vertebrae 37. 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.

COLOURATION IN ALCOHOL. Flank, dorsum and head side light yellowish grey with minute dark brown dots, slightly larger and sometimes horizontally coalesced on anterior lateral midline, more concentrated on dorsum. In juveniles below about 25 mm SL, head and trunk light yellowish grey with longitudinal row of dark brown spots on flank midline, and similar row between flank midline and venter. Barbels light grey, with brown pigmentation concentration on dorsal surface of basal portion. Fins hyaline, with minute brown dots on basal portion.

Distribution

Presently known only from the type locality, Rio Alto Pratinha, tributary of the Rio Muqui do Sul, Rio Itabapoana Basin, Serra do Mar ( Fig. 3 ).

Figures

Fig. 1. Trichomycterus (Cryptocambeva) berthalutzae sp. nov., holotype (UFRJ 12930), 78.1 mm SL. A. Left lateral view. B. Dorsal view. C. Ventral view.

Fig. 2. Osteological structures. A–C. Trichomycterus (Cryptocambeva) berthalutzae sp. nov. (UFRJ 13252).D–F. Trichomycterus (Psammocambeva) fabioheppisp. nov.(UFRJ 12933).A, D. Mesethmoidal region and adjacent structures, left and middle portions, dorsal view. B, E. Left jaw suspensorium and opercular series, lateral view. C, F. Parurohyal, ventral view. Larger stippling represents cartilaginous areas.

Fig. 3. Geographical distribution of trichomycterine catfishes in the Rio Itabapoana Basin.