Pareiorhaphis togoroi, De Oliveira & Oyakawa, 2019

De Oliveira, José C. & Oyakawa, Osvaldo T., 2019, New loricariid fishes from headwaters on Serra da Mantiqueira and Complexo do Espinhaço, Minas Gerais State, Brazil (Teleostei: Siluriformes: Loricariidae), Zootaxa 4586 (3), pp. 401-424 : 407-411

Pareiorhaphis togoroi , new species

(Figs. 2, 7; table 2)

Holotype. MZUSP 76338 , male, 66.4 mm SL, Brazil, Minas Gerais, Barbacena, upper Rio Paraná drainage, Rio Grande basin, Rio das Mortes, 21˚13’10”S 43˚37’57.6”W, 1165m asl, 29 July 2016, J.C. de Oliveira, O.T. Oyakawa, F.M.S.R. Pedro & V.C.M. Souza.

Paratypes. All from Brazil: Minas Gerais, Barbacena, upper Rio Paraná, Rio das Mortes basin : MZUSP 76339 , 1 male, 64.4 mm SL and 1 female 51.8 mm SL ; MCP 52090, male, 57.2 mm SL; MNRJ 26200 , male, 60.7 mm SL ; ANSP 203211 , male, 53.2 mm SL; DZSJRP 21190, male, 52.3 mm SL; and UFJF 3621 , 34 , 23.6–66.7 mm SL (2 c&s), collected with the holotype . UFJF 1244 , 1 , 19.6 mm SL, Córrego do Sapateiro, left bank tributary of Rio das Mortes , 21°16’33”S 43°38’40”W, 1089m asl, 24 January 1999, J.C. de Oliveira, E.S. Togoro & A.K.G. Lacerda . UFJF 1271 , 7 , 21.6–49.3 mm SL, same locality as above, 5 March 2000, J.C. de Oliveira & E.S. Togoro . UFJF 1284 , 4 , 33.9–52.8 mm SL, same locality as above, 6 May 2000, E.S. Togoro, A.K.G. Lacerda, A.A. Vidigal

& G.A. Nascimento. UFJF 1295, 2, 35.9–51.1 mm SL, same locality as above, 8 July 2000, E.S. Togoro, A.K.G. Lacerda & P.M. Cyranka. UFJF 1262, 8, 33.9–52.8 mm SL, ribeirão Senhora das Dores, right bank tributary of Rio das Mortes, 21°12’47”S 43°38’33”W, 1097m asl, 11 December 1999, E.S. Togoro, A.K.G. Lacerda & A.M. Oliveira.

Diagnosis. Pareiorhaphis togoroi is diagnosed from all congeners, except P. mucurina , by having a distinct narrow area completely devoid of papillae along and just posterior to each emergent tooth series of the dentary (vs. area posterior to tooth series of the dentary covered by papillae). It differs from P. mucurina by not having the maxillary barbel mostly adnate to lower lip by distinctly enlarged skin flap forming a continuous connection from the base to almost the end of the maxillary barbel, and having the papillae in upper lip rounded, not coalesced to form elongate skin folds anterior to the premaxillary tooth series. It differs from all Pareiorhaphis , except P. hystrix and P. parmula , by lacking azygous, preadipose plates. It can be distinguished from P. parmula by the pectoral-fin spine not broadening from base to apex on adult males (vs. contrary), and from P. hystrix by having the hypertrophied odontodes on snout of mature males thick, strong, more developed in the lateral, posterior portion of head, and longer than the dentary ramus (vs. hypertrophied odontodes on snout of mature males delicate, usually more developed on anterior portion of snout and head margins). The thick hypertrophied odontodes on snout of mature males also distinguished P. togoroi from P. splendens and P. vestigipinnis . In addition, P. togoroi can be further distinguished from P. hystrix , P. splendens and P. vestigipinnis by having the pectoral-fin spine of adult males short and not reaching to one half of the pelvic-fin length when adpressed (vs. pectoral-fin spine overlapping half length of pelvic fin when adpressed). The smaller caudal peduncle depth (6.7–8.6 vs. more than 8.6% SL) also distinguishes P. togoroi from P. azygolechis , P. bahiana , P. cameroni , P. cerosus , P. eurycephalus , P. garapia , P. garbei , P. hypselurus , P. mutuca , P. nimius , P. nudulus , P. ruschii , and P. stomias . It differs from P. lineata and P. stephana by the absence of long hypertrophied odontodes on the anterior margin of head and on the pectoral-fin spine (vs. present). It can be distinguished from P. nasuta , P. parmula and P. proskynita by the absence of a small plate on each side of the pectoral girdle, just posterior to the gill opening (vs. present). The usual presence of the adipose fin distinguishes the new species from P. proskynita and P. vestigipinnis . It differs from P. lophia by the absence of a skin fold just posterior to each emergent tooth series of dentary formed by a single enlarged, flattened papilla (vs. present), and by the higher number of dentary teeth (44–70 vs. 20–38); and from P. parmula by the lower number of dentary teeth (vs. 83–97). It can be distinguished from P. steindachneri by the largest hypertrophied odontodes on cheeks of adult males shorter than mandibular ramus (vs. longer than mandibular ramus).

Description. Morphometric and meristic data in Table 2. Standard length of measured specimens: 32.3–66.7 mm SL. See Fig. 1 for general body aspect. Dorsal surface of body covered by plates except for naked area around dorsal fin. Ventral surface of head, trunk, abdomen to anal-fin origin, and region around anal fin completely naked. Dorsal profile of body slightly convex, rising from snout tip to origin of dorsal fin and then descending to end of caudal peduncle. Ventral profile nearly straight between snout tip and caudal peduncle, slightly prominent at pelvic girdle. Greatest body width at cheeks in males and females, progressively narrowing to end of caudal peduncle. Trunk and caudal peduncle mostly ovoid in cross-section, but flattened ventrally and more compressed caudally, its depth 6.7–8.6% SL. Body moderately depressed. Greatest body depth at dorsal-fin origin, progressively narrowing to end of caudal peduncle.

Head broad and moderately depressed. Anterior profile of head rounded in dorsal view. Interorbital space slightly concave, nearly flattened. Three small ridges on dorsal surface of head, one median ridge from snout tip to area between nostrils, and one pair of ridges from nostril to anterior margin of orbit. Snout in lateral profile gently convex, covered by minute plates. Rostral plate absent. Lateral plates of margin of head covered with short odontodes, except in adult males. Adult males with well-developed soft fleshy lobes on lateral portion of head. Soft fleshy area ornamented with long and thick hypertrophied odontodes. Lateral process of cleithrum bearing delicate and short hypertrophied odontodes. Eye small, dorsolaterally placed; orbital diameter 8.8 to 13.5% HL. Iris with small dorsal flap projecting over pupil. Posterior margin of nostril closer to anterior margin of orbit than to snout tip. Lips transversely oval and well developed, occupying most of ventral surface of head. Lower lip almost reaching to pectoral girdle and covered with minute papillae, which decrease in size towards edge. Posterior edge slightly fringed. Maxillary barbel short and free distally (united to lip by membrane only basally). Mesial end of premaxilla and dentary slightly curved inwards. Teeth slender and bicuspid, inner cusp much longer, slightly curved inwards. Lateral cusp minute and pointed, never reaching one third of inner cusp.

Dorsal fin originating at vertical through pelvic-fin origin. Nuchal plate and dorsal-fin spinelet present but dorsal-fin locking mechanism non-functional. Dorsal-fin spinelet oval. Dorsal-fin spine moderately flexible, followed by seven branched rays. Adipose fin present and bearing odontodes. Adipose-fin membrane extended beyond adipose-fin spine. Unpaired pre-adipose azygous plates absent. Pectoral fin of moderate size, with spine

Lateral-line pores invisible in trunk, even in c&s specimens. Dermal plates of predorsal area arranged in four or five series. Five rows of plates between dorsal-fin base and pelvic-fin base. Lateral plates not forming keels.

Color in alcohol (Fig. 2). Adults of Pareiorhaphis togoroi with pattern of dark blotches usually arranged in inconspicuous transverse saddles on dorsum and part of flank. Overall background color of dorsal and lateral surface brown, unpigmented and yellowish pale ventrally. Five irregularly scattered darker blotches arranged in transverse saddles: first through parieto-supraoccipital, second from origin of dorsal-fin base to third branched ray, third under last dorsal-fin adpressed ray, fourth from anterior to half or all of adipose fin base, and fifth at posterior portion of caudal peduncle. Specimens from Rio das Mortes were densely pigmented, with dorsum, flank and ventral portion of caudal peduncle dark gray in most specimens, resembling P. nasuta . Others, from clear waters, with pattern of dark dots and blotches. Ventral surface of head, paired fins and abdomen pale yellow in specimens from clear waters; grayish in dark gray specimens. Ventral portion of caudal peduncle light brown in specimens with generic pattern. Paired and dorsal fins with four or five transverse regular dark bars (at last on first ray); anal fin with three or four. Caudal fin with four transverse dark bars. Interradial membrane hyaline. Some juveniles with small dark brown spots scattered all over yellowish pale body, except ventral portion of abdomen.

Color in life. Color pattern of freshly collected specimens from Rio das Mortes similar to color pattern of specimens in alcohol. Those of clear waters light brown to yellowish tan with small and irregular dark spots scattered on dorsal region of head and predorsal area.

Sexual dimorphism. Males with well-developed soft fleshy lobes ornamented with hypertrophied odontodes along lateral portion of head of adult males. Females with enlarged, swollen urogenital opening, and males with small and pointed urogenital papilla. Males with dermal flap on the dorsal surface of the pelvic-fin spine (flap absent or reduced in females). Males with well-developed fleshy flap along the entire length of the posterodorsal margin of the pectoral-fin spine (as in P. nasuta citation) as well as dorsal surface of first two branched pectoral rays and maybe also on third in some.

Etymology. The specific name, togoroi , is in honor to Eduardo Shinji Togoro, undergraduate student of the Biological Sciences Course at the Universidade Federal de Juiz de Fora, from 1998 to 2001, in recognition to his dedication and contributions to the knowledge of Serra da Mantiqueira fishes. Togoro collected, measured and studied hundreds of specimens of many species from many places in the headwaters of the four basins that originate at the Serra da Mantiqueira, in Minas Gerais State, for his undergraduate dissertation.

Distribution. Pareiorhaphis togoroi is known from the upper portion of the Rio das Mortes and two of its tributaries. (Fig. 8).

Habitat and ecological notes. The Ribeirão Senhora das Dores and the Córrego do Sapateiro are deforested and silted in a moderate degree. They reach the right and left margins (respectively) of Rio das Mortes that runs under a forested stretch at its headwaters. For this reason, the Rio das Mortes has tea colored waters, and its two tributaries have clear waters. That difference results in the intensity of pigmentation of the specimens: almost black from the Rio das Mortes and lighter from those tributaries. In both cases the color pattern is dark round dots on a lighter ground in juveniles, becoming five transverse dark saddles over a lighter ground color in adults. The species inhabits the bottoms of the under the rocks where outcrops form small waterfalls and substrates of rocks and sand.

Conservation status. Since 1999, the team of the UFJF has made extensive surveys in the region of the upper Rio das Mortes and Pareiorhaphis togoroi was recorded in only three localities with low abundance: at Rio das Mortes itself and two of its headwaters tributaries (Ribeirão Nossa Senhora das Dores and Córrego do Sapateiro). The human activity in the region comprises small farms of vegetables and dairies, and the potential threat to the species could be the siltation by improper handling of soil and pollution of watersheds by human and animal waste. The area of occupancy (AOO) of the species was estimated based on the three localities (see above) multiplied by grids of 4 km 2 totaling 12 km 2 (B2). Human activities threaten the habitat welfare (biii) of the only three localities where the species occurs (biv); hence, Pareiorhaphis togoroi was categorized as an endangered species (EN) based in the following criteria B2b(iii, iv) according to the International Union for Conservation of Nature (IUCN) categories and criteria ( IUCN Standards and Petitions Subcommittee, 2017).

Figures

FIGURE 1. Harttia intermontana, MZUSP 109337, 71.9 mm SL, male, holotype. Brazil, Minas Gerais State, Rio Doce basin. From top to bottom: dorsal, lateral and ventral views.