Rhinotocinclus hera (Gamarra, Calegari & Reis, 2019), 2022

Reis, Roberto E. & Lehmann A., Pablo, 2022, A new genus of armored catfish (Siluriformes: Loricariidae) from the Greater Amazon, with a review of the species and description of five new species, Neotropical Ichthyology (e 220002) 20 (2), pp. 1-100 : 68-70

Rhinotocinclus hera (Gamarra, Calegari & Reis, 2019) , new combination

( Fig. 38 ; Tab. 7 )

Curculionichthys hera Gamarra, Calegari & Reis, 2019:2 (Type-locality: igarapé do Onça, tributary to rio Curuá-Una on road BR-163 between Belterra and Rurópolis, Belterra, Pará, Brazil, 03º33’35.3”S 54°52’09.2”W, elevation 80 m asl. Holotype: MCP 52500).

Diagnosis. Rhinotocinclus hera is distinguished from all congeners, except for R. bockmanni , R. dani , R. pentakelis , R. marginalis n. sp., and R. loxochelis n. sp. by having the dominant color pattern formed by dark bars on body well separated and distinct (Fig. 7E; vs. dominant color pattern formed by wide dark bars partially coalesced or closed together, or formed by a dark stripe from the snout tip, through the eye and extending to end of caudal peduncle); having two separate light lines from snout tip diverging to each nostril (Fig. 6E, F; vs. light lines on snout absent, Y- or V-shaped); and, also except from R. acuen and R. dinizae , by having teeth with light ochre cusps (Fig. 5B; vs. cusps brown). Rhinotocinclus hera is further distinguished from R. britskii , R. kwarup , R. eppleyi , R. longirostris , R. polyochrus , R. variola , R. yaka , R. discolor , R. isabelae , and R. pilosus by lacking an adipose fin (vs. adipose fin present). Rhinotocinclus hera is further distinguished from congeners, except R. acuen , R. bockmanni , R. dinizae , and R. jumaorum by lacking both an adipose fin and small platelets at adipose-fin position (vs. adipose fin or small platelets present). Rhinotocinclus hera is further distinguished from R. bockmanni by lacking a triangular dark spot at the dorsal-fin membrane (vs. dorsal-fin dark spot present), and by having a conspicuous dark bar 2 on body (vs. bar 2 absent or inconspicuous); and from R. dani by having small platelets at adipose-fin position (vs. small platelets absent); and proportionally larger orbit and narrower interorbital distance (orbital diameter 44.0–50.4%; vs. 36.2–44.1% interorbital distance). Rhinotocinclus hera is further distinguished from R. pentakelis by its shallower body (body depth 14.6–17.5% vs. 18.4–20.8% SL; and caudal peduncle depth 7.8–9.3% vs. 10.1–11.7% SL); and shorter dorsal-fin spine length (21.5–25.1% vs. 27.0–30.8% SL); and from R. loxochelis n. sp. by the regularly arranged dark bars on body (vs. dark bars on body somewhat fragmented and inclined, such that they connect to form a zig-zag pattern), the shallower caudal peduncle (7.8–9.3% vs. 10.3–11.2% SL) and narrower interorbital distance (33.7–37.7% vs. 38.8–43.9% HL). Rhinotocinclus hera is further distinguished from R. marginalis n. sp. by the comparatively shallower caudal peduncle (21.3–23.5% vs. 23.3–26.3% HL).

Geographical distribution. Rhinotocinclus hera occurs in creeks tributary to the rio Curuá-Una, a small river draining to the Amazon immediately east of the town of Santarém, Pará State, Brazil ( Fig. 36 ).

Remarks. Rhinotocinclus hera was originally described as Curculionichthys hera , and accordingly was compared to other species of Curculionichthtys. Remarkably, the authors distinguished the new species from congeners, except C. jumaorum (originally described as Hisonotus ) and C. karipuna Silva, Roxo, Melo & Oliveira, 2016 , by possessing a single rostral plate (vs. paired rostral plates); and except C. jumaorum and C. sabaji Roxo, Silva, Ochoa & Oliveira, 2015 , by having darkened tooth-crowns (vs. hyaline to light yellow tipped teeth). As demonstrated in the presente study, both C. hera and H. jumaorum , belong to Rhinotocinclus and the single rostral plate and brown tooth crown are typical of its species. Rhinotocinclus hera was tentatively categorized as Least Concern (LC) by Gamarra et al. (2019) in the original description.

Material examined. Rio Curuá-Una basin, Pará State, Brazil: MCP 52500 , holotype (measured), AMNH 267150 , 7 paratypes, MCP 51571 , 70 (6 measured) + 2 cs paratypes, NUP 20539 , 7 paratypes , MZUSP 123948 , 7 paratypes, igarapé do Onça, tributary to rio CuruáUna, on road BR-163 between Belterra and Rurópolis , Belterra, 03º33’35.3”S 54°52’09.2”W . MCP 51600 , 15 paratypes (3 measured), igarapé Moju, tributary to rio Curuá-Una, on road BR-163 between Belterra and Rurópolis , Belterra, 03°25’05.8”S 54°54’46.7”W . MCP 51604 , 10, rio Curuá-Una at mouth or rio Curuá-Tinga, ca. 11 km N of Transmazon road , Placas, 03°47’56.1”S 54°21’19.3”W . MCP 53424 , 2, rio Curuá-Una at mouth or rio Curuá-Tinga, ca. 11 km N of Transamazon road, Placas, 03°47’56.1”S 54°21’19.3”W. MCP 51599, 5 (4 measured) + 1 tissue sample, rio Tutuí on Transamazon road ca. 20 km E of Placas, Uruará, 03°51’33.8”S 54°03’40.5”W .

Figures

FIGURE 36 | Geographic distribution of Rhinotocinclus species of the R. bockmanni group in southeastern Amazon basin. Rhinotocinclus bockmanni (black dots); R. dani (red dots); R. hera (pink dots); R. loxochelis n. sp. (blue dots); R. marginalis n. sp. (white dots); R. pentakelis (yellow dots). T = Type-locality.

FIGURE 38 | Rhinotocinclus hera, holotype, MCP 52500, 25.2 mm SL, female, igarapé do Onça, tributary to rio Curuá-Una, on road BR-163 between Belterra and Rurópolis, Belterra, Pará, Brazil.