A new species of Panaqolus (Siluriformes: Loricariidae) from the rio Branco

Abstract

A new species of Panaqolus is described from material from the Takutu River and the mainstem rio Branco. The new species is diagnosed from congeners by its color pattern consisting of dark and light bars on the body, bands on the fins, and with dots and vermiculations absent (vs. no bars in P. albomaculatus, P. nix, P. nocturnus, and P. koko, vs. fins unbanded in P. albomaculatus, P. dentex, P. koko, and P. nix, and vs. dots and vermiculations present in P. albivermis and P. maccus). The new species is diagnosed from barred species of Panaqolus by its specific bar number and orientation and color pattern on its head, with bars oriented in a anteroventral-posterodorsal direction (vs. anterodorsal-posteroventral bars in P. gnomus), having consistently 5 bars (n = 4) on the trunk that do not increase with size (vs. number increasing with size in P. purusiensis and vs. 6-12 in P. changae), and the color pattern on the head of straight lines extending from posterior to the eye to the snout margin, splitting in the middle portion of the line in larger specimens (vs. small, dense reticulate lines in P. changae). Biogeographically, we infer that the new species ancestrally originated in the Amazon river, dispersing to the Takutu River after the Amazon captured part of the Proto-Berbice. Uma espécie nova de Panaqolus é descrita do rio Branco e seu afluente, rio Tacutu. A nova espécie é diagnosticada de suas congêneres pelo padrão de colorido composto por barras escuras e claras alternadas no corpo e nadadeiras, não formando máculas ou vermiculações nas nadadeiras (vs. sem barras no corpo em P. albomaculatus, P. nix, P. nocturnus, e P. koko, e vs. sem barras nas nadadeiras em P. albomaculatus, P. dentex, P. koko, e P. nix, e vs. máculas e vermiculações presentes em P. albivermis e P. maccus). A nova espécie é diagnosticada das espécies de Panaqolus com barras pelo número e orientação das barras e pelo padrão de colorido cefálico, com as barras orientadas posterodorsalmente (vs. posteroventralmente em P. gnomus), pela presença de cinco barras (n = 4) no tronco que não aumentam com o tamanho (vs. número aumentando com o tamanho em P. purusiensis e vs. 6-12 barras em P. changae), e o padrão de colorido cefálico composto por linhas retas da margem posterior do olho à margem do focinho, dividida medianamente em indivíduos maiores (vs. linhas pequenas e vermiculadas em P. changae). Nos inferimos que a nova espécie originou-se ancestralmente no rio Amazonas, dispersando para o rio Tacutu após o Amazonas capturar parte do Proto-Berbice.

Cytogenetic Analysis of <b><i>Panaqolus tankei</i></b> Cramer &amp; Sousa, 2016 (Siluriformes, Loricariidae), an Ornamental Fish Endemic to Xingu River, Brazil

“…Despite the huge diversity of species found in Loricariidae, the lack of cytogenetic data for many genera and clades impairs the knowledge about the chromosomal relationships and the impact of chromosomal changes on their evolutionary history. This is the case for the genus Panaqolus, which harbors several putatively undescribed species [Lujan et al, 2015;Cramer and Melo de Sousa, 2016;Tan et al, 2016], and whose chromosomal characteristics are almost completely unknown. With the exception of Ancistrus species, where the differentiation of the karyotype is mostly associated with reduction of the dip-loid number and a range of karyotype rearrangements [de Oliveira et al, 2007[de Oliveira et al, , 2008[de Oliveira et al, , 2009, there is an overall trend of maintenance of the diploid number 2n = 52 in Ancistrini species [Medeiros et al, 2016;Ayres-Alves et al, 2017;Pety et al, 2018; present study].…”

“…Panaqolus tankei Cramer & Sousa, 2016 was described from Xingu River, Brazil [Cramer and Melo de Sousa, 2016], where it is highly exploited for the international aquarium trade [Lujan et al, 2017]. This species differs from its congeneric species by possessing dark and light bars of similar width [Cramer and Melo de Sousa, 2016], but differences in relation to some closely related species may be subtle (e.g., Panaqolus claustellifer Armbruster, Sousa & Tan, 2016 from the Negro River basin) [Tan et al, 2016]. Interestingly, refined molecular analyses among the Ancistrini tribe suggest that Panaqolus is more closely related to Peckoltia Miranda Ribeiro, 1912 andScobinancistrus Isbrücker &Nijssen, 1989 than to Panaque Eigenmann & Eigenmann, 1889 species [Lujan et al, 2017;Roxo et al, 2019], as previously hypothesized due to the presence of few comb-shaped teeth in the premaxillary and dental bones in Panaque and Panaqolus [Chockley and Armbruster, 2002;Lujan et al, 2010].…”

A New Species of Tiger Pleco Panaqolus (Siluriformes: Loricariidae) from the Xingu Basin, Brazil

“…tankei have 3 to 4 dark bands in the dorsal fin which are orientated non-parallel to the margin of the fin, whereas P . claustellifer has only two bands and these are parallel to the margin of the fin [26]. Barcode sequences [12] from seven P .…”

Connectivity of Neotropical River Basins in the Central Guiana Shield Based on Fish Distributions

“…vittatus and algivore/detrivore Steindachnerina planiventris (Vari, 1991;Vari and Raredon, 1991). Armored catfishes Hypostomus macushi and Panaqolus claustellifer are closely associated with woody debris and most often found in the rivers associated with the forest (Armbruster and de Souza, 2005;Tan et al, 2016).…”