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| Curimatopsis sabana Melo, 2020 |
A new species of Curimatopsis is described from the highlands of the western Guiana Shield in the río Carapo and río Paragua, tributaries of the río Caroni in the Orinoco basin, southeastern Venezuela. The new species belongs to the Curimatopsis macrolepis clade due to its possession of a long lower jaw that projects past the anterior margin of the upper jaw, and separate first and second hypurals. The new species is diagnosed from remaining species of the Curimatopsis macrolepis clade by having a small-sized inconspicuous dark spot on the midlateral surface of the caudal peduncle, by details of body and fin pigmentation, and by additional morphometric characters. The distribution of C. macrolepis in the Amazon and Orinoco basins is updated based on the examination of museum specimens.
Keywords: Gran Sabana; Guiana Shield; Ostariophysi; Teleostei
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| FIGURE 1: Curimatopsis sabana, AMNH 274996, holotype, 36.5 mm SL, female, Venezuela, Bolívar, río Paragua, río Caroni, Orinoco basin (top). AUM 36458, paratype, 43.5 mm SL, male, Venezuela, Bolívar, río Paragua, río Caroni, Orinoco basin (bottom). |
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| FIGURE 4: Species of the Curimatopsis macrolepis clade: A-B) C. macrolepis, LBP 22425, rio Solimões, Letícia, Colombia; C) C. jaci, female, MZUSP 121197, holotype, rio Cristalino, upper Tapajós basin; D) C. jaci, male, MZUSP 116668, paratype, rio São Benedito, upper Tapajós basin; E) C. maculosa, LBP 13907, paratype, middle rio Tapajós; F) C. melanura, MPEG 15335, holotype, rio Nhamundá; G) Curimatopsis sabana, female, AMNH 274996, holotype, río Caroni basin; H) C. sabana, male, AUM 36458, paratype, río Caroni basin. Photos by Bruno Melo (A-E, G-H) and Guilherme Dutra (F). |
Curimatopsis sabana, new species
Diagnosis. Curimatopsis sabana belongs to the C. macrolepis clade (C. jaci Melo, Oliveira, 2017, C. maculosa Melo, Vari, Oliveira, 2016, C. macrolepis, and C. melanura Dutra, Melo, Netto-Ferreira, 2018) and can be easily diagnosed from species of the C. evelynae clade (C. cryptica Vari, 1982, C. evelynae, C. guaporensis Melo, Oliveira, 2017, C. myersi Vari, 1982, and C. pallida Melo, Oliveira, 2017) by having a longer lower jaw that projects past the anterior margin of the upper jaw (vs. lower jaw shorter and not overlapping the upper jaw), and by separate (vs. fused) first and second hypurals. Within the C. macrolepis clade, C. sabana is diagnosed from C. melanura by the absence (vs. presence) of the dark pigmentation on the entire lower lobe of the caudal fin. It differs from C. jaci by the absence (vs. presence) of a distinctly reticulate color pattern on the flanks of females. It is diagnosed from C. maculosa by the possession of a round spot of black pigmentation, sometimes very faint, on the midlateral surface of the caudal peduncle (vs. a small posteriorly pointed spot overlapping the posterior midlateral scales), by the absence (vs. presence) of a gap of two or three scales separating the pigmentation of the midlateral stripe and the dark spot on caudal peduncle, by a deeper body, 34.1-39.9% of SL (vs. 26.0-31.6% of SL), and deeper caudal peduncle, 13.7-17.4% of SL (vs. 9.0-13.7% of SL). It differs from C. macrolepis by the possession of a circular and weakly pigmented spot on the caudal peduncle (vs. horizontally elongated and strongly pigmented dark spot on caudal peduncle). Finally, it differs from C. microlepis by 26-28 (vs. 57-63) scales in the longitudinal series from the supracleithrum to the hypural joint.
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| FIGURE 2: Map of northern South America showing the collection localities of species of the Curimatopsis macrolepis clade in the Orinoco and Amazon basins. Note the distribution of Curimatopsis sabana in highlands of the Guiana Shield. T = type locality. |
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| FIGURE 3: Habitat of Curimatopsis sabana, AUM 36458, a drying pool of the río Paragua, tributary of the río Caroni. Photograph by J.W. Armbruster. |
Distribution. Curimatopsis sabana is only known from the Carapo and Paragua rivers, which are tributaries of the río Caroni, itself a right-bank tributary of the río Orinoco basin, in the western Guiana Shield in Venezuela (Fig. 2). Various specimens were collected in the region of the río Carapo, near Cerro Guaiquinima (4 km along the river, 300-310 m asl), and one specimen was collected in a drying pool of the lower río Paragua (272 m asl) (Fig. 3). The distribution suggests that C. sabana is restricted to higher elevations of the western Guiana Shield.
Etymology. The specific name sabana refers to the Gran Sabana, a major ecoregion in the western Guiana Shield of southeastern Venezuela, which encompasses the río Caroni basin. A noun in apposition.
Bruno F. Melo. 2020. New Species of Curimatopsis from the río Caroni, Orinoco basin, Venezuela, with Comments on C. macrolepis (Characiformes: Curimatidae). Neotrop. ichthyol. 18(2). DOI: 10.1590/1982-0224-2020-0002
Palavras-chave: Gran Sabana; Escudo das Guianas; Ostariophysi; Teleostei
