Rhinotocinclus eppleyi (Schaefer & Provenzano, 1993), new combination

(Figs. 20–21; Tab. 4)

Parotocinclus eppleyi Schaefer & Provenzano, 1993:46 (Type-locality: Venezuela, Amazonas, caño Curicurito, approx. 1 km above its mouth into the Río Autana, Río Sipapo drainage, 04°47’N 67°25’W. Holotype: MBUCV-V-22530).

Diagnosis. Rhinotocinclus eppleyi is distinguished from R. acuen, R. bockmanni, R. chromodontus, R. dani, R. dinizae, R. hera, R. jumaorum, R. pentakelis, R. marginalis n. sp., and R. loxochelis n. sp. by possessing an adipose fin (vs. adipose fin absent), and by having a Y-shaped light mark from the snout tip to each nostril (Figs. 7A,B; vs. light mark V-shaped or present as two separate lines from snout tip diverging to each nostril). It is distinguished from R. collinsae, R. halbolthi, and R. hardmanni by lacking accessory teeth on both premaxilla and dentary (Figs. 5B, C; vs. accessory teeth present, Fig. 5A); the odontodes on the ventral surface of first pelvic-fin ray bent and pointing mesially (Fig. 9A; vs. odontodes aligned with main ray axis, Fig. 9B); a triangular dark spot on the anterior portion of the dorsal-fin membrane (Fig. 8B; vs. dorsal-fin spot absent); a Y-shaped light mark from snout tip to nostrils (vs. Y-shaped light mark absent); and a larger orbit, 26.7–31.4% snout length (vs. orbit 18.9–24.6% snout length). Rhinotocinclus eppleyi is distinguished from R. britskii and R. kwarup, by having the snout more acutely pointed (Fig. 11B; vs. snout more broadly rounded, Fig. 11A); dark bars on body wider and closer together (Fig. 7B; vs. dark bars on body narrower and more widely spaced, Fig. 7A); and 3–4 plates between the posterior border of the rostral plate and the nostril (Fig. 12A; vs. one plate). Rhinotocinclus eppleyi is distinguished from R. polyochrus, R. variola, R. yaka, R. discolor n. sp., R. isabelae n. sp., and R. pilosus n. sp. by having 4–5 irregular series of middle abdominal plates (vs. 0–2, rarely 3 irregular series); and five dark bars on body; vs. four dark bars with bars 1+2 or 2+3 fused). It is distinguished from R. longirostris by having fewer premaxillary (22–30, mode 26) and dentary (21– 27, mode 25) teeth (Tabs. 1–2, vs. more numerous premaxillary, 28–36, mode 30 and dentary, 27–31, mode 30 teeth).

Geographical distribution. Rhinotocinclus eppleyi occurs in the upper Río Orinoco basin in the states of Apure, Bolivar, and Amazonas of Venezuela (Fig. 15). Despite no specimens were available, R. eppleyi also occurs in the states of Vichada and Guainía of Colombia, just across the Río Orinoco (Maldonado-Ocampo et al., 2008; DoNascimiento et al., 2017).

Remarks. Rhinotocinclus eppleyi is most similar and scarcely distinguished from R. longirostris, the only phenotypical differences being the numbers of premaxillary and dentary teeth – see Remarks for R. longirostris for details. Rhinotocinclus eppleyi is currently not assessed by IUCN.

Material examined. Río Orinoco basin, Venezuela: ANSP 165845, 11 + 2 cs paratypes, Caño Potrerito, tributary to Río Cinaruco, 24 km S of Rio Cinaruco on road from San Fernando de Apure to Puerto Paez, Apure, approx. 06°25’N 67°32’W. ANSP 165846, 1 paratype, Caño Horeda, at border of Bolivar-Amazonas states, ca. 68 km NE of Puerto Ayacucho, on road from Puerto Ayacucho to Puerto Paez, Amazonas, 06°07’39”N 67°22’01”W. ANSP 169470, 8 paratypes, Caño Curicurito, ca. 1 km above its mouth into Río Autana, Amazonas, 04°47’16”N 67°24’30”W. MCP 33313, 8 (8 measured) + 2 cs paratypes (formerly MBUCV-V 22524), Caño Curicurito, ca. 1 km from mouth of Río Autana, Río Sipapo basin, Amazonas, approx. 04°47’N 67°25’W. ANSP 160700, 5 + 1 cs, Río Sipapo, ca. 6 km upstream from Pendare, Amazonas, 04°52’29”N 67°43’16”W. AUM 22338, 2, Caño Ore, ca. 50 km SW of Los Pijiguaos, on road from Caicara to Puerto Ayacucho, Bolívar (06°18’57” N 67°05’46” W). AUM 22635, 6, Caño Potrerito, ca. 15 km N of Puerto Paez on road to San Fernando, Apure, 06°24’43”N 67°31’55”W. FMNH 85863, 1, Río Orinoco, 13 km S of Puerto Nuevo toward Puerto Ayacucho, Rio Orera basin, Amazonas, 05°06’52.73”N 67°48’10.46”W. FMNH 103541, 40 of 162, Caño Curcurito, ca. 1 km above mouth in Río Autana, Amazonas, 04°43’48”N 67°37’12”W. FMNH 108763, 1, Río Sipapo, ca. 1.5 h above Pendare, Amazonas, 04°45’24”N 67°43’17”W. MCNG 3010, 3 of 4, Río Manapiare near Yutaje, Amazonas, 05°32’50”N 66°06’57”W. MCNG 6957, 15 of 111, Río Naure near Hato Lagunitas, S of Apure, Apure, 06°50’10”N 68°32’10”W. MCNG 21655, 1, Río Guayapo ca. 100 km from mouth with Río Sipapo, Amazonas, approx. 04°37’N 67°19’W. MCNG 21698, 3, Río Sipapo ca. 150 m from Salto Remo, Amazonas, 04°34’28”N 67°18’31”W. MCNG 22184, 1, flooded forest on left bank of Río Guayapo, 9 km from mouth into Río Sipapo, Amazonas (approx. 04°31’ N 67°35’ W). MCNG 22306, 1, Río Guayapo at Aguacate rapids, upstrem from confluence with Río Sipapo, Amazonas, approx. 04°20’N 67°30’W. MCNG 23323, 3, beach of Río Guainia at Maroa, Amazonas, approx. 02°44’N 67°34’W. MCNG 23591, 2, Caño Chimita, tributary to Río Atacavi-Atabapo, 10 km from confluence with Río Atacavi, Amazonas, approx. 03°03’N 67°01’W. MCNG 25886, 1, Río Orinoco downstream from Village of Cariche, Amazonas, approx. 03°02’N 66°25’W. MCNG 26630, 20 of 30, Caño Topocho at road from Caicara to Puerto Ayacucho, Amazonas, approx. 05°57’N 67°22’W. MCNG 33131, 4 + 1 cs, Río Autana at Raudal Pereza, Amazonas, 04°46’4.22”N 67°27’28.34”W. MCNG 34147, 2, Río Cinaruco, Apure, approx. 06°32’N 67°24’W. MCNG 39512, 13, beach at Río Cinaruco, Apure, 06°32’45”N 67°25’00”W. MCNG 41450, 3, Río Cinaruco, Apure, 06°32’31”N 67°24’31”W. MCNG 41460, 3, Río Cinaruco, Apure, 06°32’30”N 67°24’05”W. MCNG 44274, 3, Río Yatua, Amazonas, 01°28’01”N 66°08’55”W. ROM 88301, 12 (2 measured), MCP 54750 10, (3 measured), Caño Parhueña, upstream route 12, ca. 35 km NE of Puerto Ayacucho, Amazonas, 05°53’30.66”N 67°24’13.54”W.