Description of a new species of Tatia from rio Tocantins drainage, central Brazil, with notes on Tatia simplex Mees, 1974 (Siluriformes, Auchenipteridae)

Abstract

Tatia comprises twenty-five valid species, distributed in the main inland watersheds of South America, including the Orinoco, Essequibo, and coastal rivers of Suriname, Amazon, upper rio Paraná and São Francisco basins. A new species is described from tributaries of upper rio Manuel Alves on uplands of Serra Geral do Tocantins plateau, Tocantins State, Brazil. It is promptly distinguished from all congeners, except Tatia britskii, due to absence of an adipose fin. It differs from T. britskii by the longer caudal peduncle length (24.1–30.5% SL, mean 25.3 vs. 20.0–22.7, mean 20.9); caudal peduncle depth (10.9–16.8 SL, mean 14.1 vs. 9.4–10.5, mean 9.8), and anterior cranial border with mesethmoid width equals its length (vs. width approximately three times its length in T. britskii). Additionally, information regarding the poorly known species Tatia simplex originally described from rio das Mortes, is provided.

Quantifying shortfalls in the knowledge on Neotropical Auchenipteridae fishes

“…This monograph set up the basis for the recent increase in taxonomic effort (1980–2017), thanks to the work of dozens of researchers around the world, especially the North Americans Carl J. Ferraris, Richard Vari and Stephen Walsh, and the Brazilians José Birindelli, Luiza M. Sarmento‐Soares, Frank Ribeiro and Bárbara B. Calegari. This high rate of description continues to date, with the recent description of Spinipterus moijiri Rocha, Rossoni, Akama, & Zuanon, 2019, Tatia caudosignata DoNascimiento, Albornoz‐Garzón & García‐Melo 2019, and Tatia akroa Souza, Sarmento‐Soares, Canto & Ribeiro 2020, which we did not include in the analyses.…”

“…The recent species‐level phylogeny of Calegari et al. (2019) is the first to include a large proportion of the species of the family (97 out of 124 valid species; updated to 126 species after Rocha et al., 2019; Souza, Sarmento‐Soares, Canto, & Ribeiro, 2020). It is also a pioneer in the use of molecular data under a total evidence approach, in contrast to all former hypotheses based only on morphological data.…”

“…This incongruity is the biggest obstacle for the fulfilment of phylogenetic gaps (Assis, 2018;Diniz-Filho, Loyola, Raia, Mooers, & Bini, 2013;Hortal et al, 2015) and calls for an even more comprehensive survey of the family. The recent species-level phylogeny of Calegari et al (2019) is the first to include a large proportion of the species of the family (97 out of 124 valid species; updated to 126 species after Rocha et al, 2019;Souza, Sarmento-Soares, Canto, & Ribeiro, 2020).…”