Curimatus albula Lütken 1874

Dutra, Guilherme Moreira, Penido, Iago De Souza, Pessali, Tiago Casarim & Netto-Ferreira, Andre Luiz, 2017, Ressurrection of Curimatus albula Lütken (Characiformes: Curimatidae), a senior synonym of Cyphocharax lundi Dutra, Penido, Mello & Pessali, Zootaxa 4344 (3) : 597-598

Curimatus albula Lütken 1874

was described from the Ribeirão da Mata at Lagoa Santa, a tributary of Rio das Velhas, Rio São Francisco basin. The species validity was questioned by Lütken (1875) himself, who suggested that the species could be a synonym of Curimatus gilbert Quoy & Gaimard , a species described from the Rio Macacu, a coastal river tributary of Guanabara bay, Rio de Janeiro. That synonymy was only formally proposed by Eigenmann (1910), and followed by most subsequent authors (e. g. Nielsen, 1974; Vari, 1992), except for Fowler (1975), who erroneously listed C. albula as the senior synonym of C. gilbert . Vari (1989) posteriorly removed both nominal species from Curimatus Oken (= Curimata Bosch ) reallocating them in Cyphocharax Fowler , based on the lack of synapomorphic conditions present in other valid curimatid genera. Vari (1989) considered that those nominal species belonged to a major group within Cyphocharax also including C. grandocule Fernández-Yépez , C. modestus Fernández-Yépez , C. santacatarinae Fernández-Yépez , and C. voga Hensel , based on the presence of a rhomboidal caudal pigmentation and “random body spotting”. Later, Vari (1992) included C. grandocule along with C. albula in the synonymy of C. gilbert , and listed several characters allowing further distinction of that species from the remaining species of the group (i.e., number of vertebrae, scales in transverse series, and pigmentation characters). Among the characters involving the pigmentation pattern, Vari (1992) stressed the lack of randomly arranged dark spots on the lateral and dorsolateral surfaces of the body in C. gilbert (versus present in C. voga ).

Contradicting Vari (1992), the examination of type specimens of Curimatus albula revealed the presence of a series of dark blotches along the mid-lateral portion of the body ( Fig. 1A–B ). Although fainted, the presence of such character in C. albula was reported in the redescription of the species, and also reported in Reinhardt’s field notes ( Lütken, 1875, 2010). Subsequent authors (e. g. Eigenmann, 1910; Nielsen, 1974; Vari, 1992) failed to recognize such distinguishing character from C. gilbert , which lacks those pigmentation elements on the lateral and dorsolateral surfaces of the body as diagnosed by Vari (1992). Indeed, those pigment elements are absent in specimens of C. gilbert from its type locality and throughout its distribution range along the Brazilian coastal drainages. Moreover, C. albula also differs from C. gilbert by the inconspicuous longitudinal stripe, the presence of light brown spots on the dorsal portion of flanks and the narrow, horizontally ovate caudal blotch. These findings are considered herein a refutation of the traditional synonymy between Curimatus albula and Cyphocharax gilbert , and we consider that the former should be recognized distinct from the latter, keeping the combination proposed by Vari (1989) as Cyphocharax albula .

Additionally to the recognition of Cyphocharax albula as a valid species, lies the fact that C. lundi Dutra, Penido, Mello & Pessali ( Fig. 1C ) was also described from a tributary of the Rio das Velhas ( Dutra et al., 2016). Meristic, morphometric ( Table 1), and coloration pattern comparisons between type specimens of both species completely overlapped not allowing the recognition of C. lundi as a valid species. Therefore, C. albula should be kept as the valid name given its priority (ICZN Article 23). In addition to the nomenclatural changes proposed above, it is also suggested herein that the diagnosis of C. albula should be the same as that proposed by Dutra et al. (2016) to distinct its junior synonym from all congeners: the presence of 7–11 midlateral blotches along the lateral line, the presence of light brown spots on the dorsal portion of flanks; the presence of 1–2 pored scales posterior to the hypural joint; the complete lateral line; and the presence of 5–6 scales rows above lateral line.

Examined material. In addition to the material examined in Dutra et al. (2016), the following specimens were examnined in the present study: Cyphocharax albula : MCNIP 807, holotype of Cyphocharax lundi , 73.7 mm SL. MCNIP 1611, paratype of Cyphocharax lundi , 1, 84.6 mm SL. MNHN 9588, paralectotypes of Curimatus albula , 2, 56.2-64.2 mm SL. MNRJ 49066, 1, 125.7 mm SL. MPEG 33715, paratype of Cyphocharax lundi , 1, 69.9 mm SL. MZUSP 73728, 1, 71.2 mm SL. MZUSP 73732, 1, 90.1 mm SL. ZMUC P241361 (formelly ZMUC 52), lectotype of Curimatus albula (only photos and X-ray), 81.7 mm SL. Cyphocharax gilbert : CAS 20352, holotype of Pseudocurimata grandocule (only photos and X-ray), 80.6 mm SL. MNHN 5430, holotype of Curimatus gilbert , 83.2 mm SL. MZUSP 1958, paratype of Pseudocurimata grandocule , 1, 121.7 mm SL.

Figures

FIGURE 1. Lateral view of Cyphocharax albula: A) MNHN 9588, paralectotype, 56.2 mm SL, Lagoa Santa, Minas Gerais, Brazil; B) Same specimen with highlighted lateral blotches. C) Holotype of Cyphocharax lundi, MCNIP 807, 73.7 mm SL, Confins, Minas Gerais, Brazil.