A new species of Eigenmannia Jordan and Evermann (Gymnotiformes: Sternopygidae) from the upper rio Paraguai basin

Abstract

Eigenmannia correntes, a new species belonging to the Eigenmannia trilineata species-group, is described from tributaries of rio Correntes, a major affluent of the rio Piquiri system, upper rio Paraguai basin (Mato Grosso and Mato Grosso do Sul states, Brazil). Eigenmannia correntes is included in the currently poorly defined sternopygid genus Eigenmannia (Ostariophysi: Gymnotiformes) by presenting characters that are either primitive or of uncertain polarity, such as eyes covered by skin, scales present over entire postcranial portion of body, teeth absent from oral valve, infraorbital bones 1+2 with enlarged posterodorsal expansion, and gill rakers short and unossified. The new species is distinguished from all congeners, except those species included in the Eigenmannia trilineata species-group, by the presence of a conspicuous superior midlateral stripe (synapomorphy of this clade). Eigenmannia correntes can be differentiated from all members of the Eigenmannia trilineata species-group, except E. vicentespelaea, E. waiwai and E. besouro, by its subterminal mouth (vs. terminal in remaining species of that group). Further, it differs from these aforementioned species by a number of meristic and morphometric characters, including number of premaxillary and dentary teeth, number of longitudinal series of scales above lateral line, number of pectoral-fin and anal-fin rays, eye diameter, postorbital distance, and snout length. Finally, notes on reproduction and parasitism for E. correntes are presented.

New species of glass knifefish genus Eigenmannia (Gymnotiformes: Sternopygidae) with comments on the morphology and function of the enlarged cephalic lateral‐line canals of Sternopygidae

“…absence). The new species can be distinguished from all species of the E. trilineata species group, except Eigenmannia besouro Peixoto & Wosiacki, 2016, Eigenmannia correntes Campos‐da‐Paz & Queiroz, 2017, E. sirius , Eigenmannia vicentespelaea Triques 1996 and Eigenmannia waiwai Peixoto et al ., 2015, by the subterminal mouth ( vs . terminal).…”

“…Despite several recent taxonomic contributions (Campos‐da‐Paz & Queiroz, 2017; Dutra et al ., 2017, 2018; Herrera‐Collazos et al ., 2020; Peixoto et al ., 2015; Peixoto & Ohara, 2019; Peixoto & Waltz, 2017; Peixoto & Wosiacki, 2016; Waltz & Albert, 2018), the monophyly of Eigenmannia still awaits further phylogenetic studies, and currently its infrageneric classification is based on informal groups of species (see discussion in Peixoto & Ohara, 2019: Table 2). Among these, the Eigenmannia trilineata species group allocates the highest number of species and encompasses taxa that exhibit a midlateral stripe between the LL and the proximal portion of the pterygiophores of the anal fin, named the ‘superior midlateral stripe’ (Peixoto et al ., 2015; Peixoto & Wosiacki, 2016).…”

Morphology‐based phylogeny of Eigenmanniinae Mago‐Leccia, 1978 (Teleostei: Gymnotiformes: Sternopygidae), with a new classification

“…These values were normalized in a range that corresponds from 0 (minimum value) to 1 (maximum value; for observed values and their normalizations see Table –) for analyses, following the methodology synthesized and justified in Ferrer et al (2014). The range of the observed values for all taxa were acquired directly from specimens analyzed herein, and compiled from the literature in order to apply the largest range known for each count [ Archolaemus species: Vari et al (2012); Distocyclus species: Dutra et al, (2014), Meunier et al, (2014); Eigenmannia species: Peixoto et al (2015), Peixoto and Wosiacki (2016), Peixoto and Waltz (2017), Campos‐da‐Paz and Queiroz (2017), Dutra et al (2017), Dutra et al (2018); Japigny : Meunier et al (2011); Rhabdolichops species: Lundberg and Mago‐Leccia (1986), Correa et al, (2006); Brachyhypopomus brevirostris : Crampton et al (2016); Gymnotus coropinae : Crampton and Albert (2003); Sternarchorhamphus muelleri : Campos‐da‐Paz (1995)].…”

A new species of the Eigenmannia trilineata (Gymnotiformes: Sternopygidae) species group from the río Orinoco basin, Venezuela

“…Following a series of contributions (Eigenmann, 1893;Jordan, Evermann, 1896;Ellis, 1913;Mago-Leccia, 1994;Triques, 1996;Albert, 2001;Peixoto et al, 2015;Peixoto, Wosiacki, 2016;Campos-da-Paz, Queiroz, 2017), seventeen species are currently recognized as valid in the genus Eigenmannia: E. antonioi Peixoto, Dutra & Wosiacki, 2015 from the rio Anapu, rio Amazonas basin; E. besouro Peixoto & Wosiacki, 2016 from tributaries in the rio São Francisco basin; E. correntes Campos-da-Paz & Queiroz, 2017 from the rio Correntes, rio Paraguay basin; E. desantanai Peixoto, Dutra & Wosiacki, 2015 from the rio Cuiabá, rio Paraguay basin; E. guairaca Peixoto, Dutra & Wosiacki, 2015 from the riacho Água do Ò, upper rio Paraná basin; E. humboldtii (Steindachner, 1878) from the río Magdalena; E. limbata (Schreiner & Miranda Ribeiro, 1903) from the Amazonas basin; E. macrops (Boulenger, 1897) from the Amazonas, Orinoco, and Guyanas basins; E. matintapereira Peixoto, Dutra & Wosiacki, 2015 from the rio Uneiuxi and rio Urubaxi, rio Negro basin; E. microstoma (Reinhardt, 1852) from the rio São Francisco basin; E. muirapinima Peixoto, Dutra & Wosiacki, 2015 from small tributaries of the Amazon River; E. nigra Mago-Leccia, 1994 from the rio Negro, río Orínoco, and rio Amazonas basins; E. pavulagem Peixoto, Dutra & Wosiacki, 2015 from tributaries of the rio Capim, rio Guamá basin; E. trilineata López & Castello, 1966 from the río de La Plata and rio Paraná; E. vicentespelaea Triques, 1996 from the São Vicente I and II caves, rio Tocantins basin; E. virescens (Valenciennes, 1836) from the rio Paraná; and E. waiwai Peixoto, Dutra & Wosiacki, 2015 Peixoto et al (2015) proposed a new classification for the longitudinally striped species, erecting the Eigenmannia trilineata species group, consisting of E. antonioi, E. desantanai, E. guairaca, E. matintapereira, E. microstoma, E. muirapinima, E. pavul...…”

“…desantanai, E. guairaca, E. matintapereira, E. microstoma, E. muirapinima, E. pavulagem, E. trilineata, E. vicentespelaea, and E. waiwai (thus removing E. microstoma from the E. microstoma species group and E. trilineata from the E. virescens species group). Most recently, two species were described for the group, E. besouro and E. correntes (Peixoto, Wosiacki, 2016;Campos-da-Paz, Queiroz, 2017). All current members of the Eigenmannia trilineata species group are found in the Amazon, Paraguay, Paraná, La Plata, and São Francisco drainages.…”