Miniature catfishes of the genus Gelanoglanis (Siluriformes: Auchenipteridae): monophyly and the description of a new species from the upper rio Tapajós basin, Brazil

Abstract

Previously proposed synapomorphies for the genus Gelanoglanis of the catfish family Auchenipteridae are evaluated and four additional features involving the relationship between the mesethmoid and premaxilla, the very fleshy anterior portion of the snout, the lack of ossification of the second through fourth infraorbitals, and the incomplete poring of the lateral line are hypothesized as synapomorphic for the members of the genus. A new species of Gelanoglanis is described based on a series of specimens collected in the rio Teles Pires, a tributary of the rio Tapajós in the southern reaches of the Amazon basin. The new species demonstrates a number of features unusual within Gelanoglanis including a fontanel bordered by the frontals, a particularly elongate gonopodium in mature males, reductions in the dentition on the premaxilla, and a shorter posterior extension of the maxilla inside the maxillary barbel. The new species is a miniature as evidenced both by its body size and the reductions of various ossifications of the head, the number of fin rays and of the laterosensory canal system on the head and body.Sinapomorfias propostas previamente para o gênero Gelanoglanis da família Auchenipteridae são avaliadas e quatro características adicionais que envolvem a relação entre o mesetmóide e a pré-maxila, a porção anterior do focinho carnosa, a perda de ossificação do segundo ao quarto infraorbital e linha lateral incompleta são hipotetizadas como sinapomórficas para os membros do gênero. Uma espécie nova de Gelanoglanis é descrita com base em uma série de exemplares coletados no rio Teles Pires, um tributário do rio Tapajós na porção sul da bacia Amazônica. A espécie nova possui várias características incomuns dentro de Gelanoglanis, incluindo uma fontanela bordeada pelos frontais, um gonopódio particularmente longo em machos maduros, redução da dentição na premaxila, e extensão posterior da maxila mais curta dentro do barbilhão maxilar. A espécie nova é uma miniatura, como evidenciado não apenas pelo tamanho reduzido do corpo, como também pela redução da ossificação da cabeça, do número de raios e do sistema de canais látero-sensoriais da cabeça e do tronco.

New species of the miniature genus Gelanoglanis (Siluriformes: Auchenipteridae) from the Tocantins River basin (Brazil) and osteological description of G. nanonocticolus

“…The new species shares with congeners all synapomorphies previously proposed for the genus (Böhlke, 1980;Soares-Porto et al, 1999;Calegari et al, 2014), except for the absence of serrae on the anterior margin of the pectoral-fin spine. Gelanoglanis varii also shares with congeners the presence of a series of soft and rounded papillae along the maxillary barbel, corroborating that feature as a potential additional synapomorphy for the genus [a complete description of this structure was given by Calegari et al (2014)]. Additionally, a new putative synapomorphy for Gelanoglanis is the very elongate dorsal process of the cleithrum, with approximately the same length as the first unbranched pectoral-fin ray, as observed in G. varii (Fig.…”

“…The Auchenipteridae, known as driftwood catfishes, is a monophyletic group with 116 valid species known to date, arranged in 22 genera (updated from Ferraris, ). Gelanoglanis Böhlke 1980 is a very distinctive genus and currently known as a monophyletic taxonomic unit of the subfamily Centromochlinae, diagnosed by 15 morphological synapomorphies (Böhlke, ; Soares‐Porto et al , ; Calegari et al , ). Gelanoglanis has four valid species distributed in the Orinoco River ( Gelanoglanis stroudi Böhlke 1980), middle Negro River and upper Orinoco River ( Gelanoglanis nanonocticolus Soares‐Porto, Walsh, Nico & Netto 1999), upper Amazon River basin ( Gelanoglanis travieso Rengifo & Lujan 2008) and upper Tapajós River basin ( Gelanoglanis pan Calegari, Reis & Vari 2014).…”

“…Tel. : +55 (51) 3353 4413; email: reis@pucrs.br Soares-Porto, Walsh, Nico & Netto 1999), upper Amazon River basin (Gelanoglanis travieso Rengifo & Lujan 2008) and upper Tapajós River basin (Gelanoglanis pan Calegari, Reis & Vari 2014). Although the genus is currently represented by a low number of species, it is expected to include a greater diversity.…”

First record of the driftwood catfish Spinipterus acsi Akama & Ferraris, 2011 (Siluriformes, Auchenipteridae) for Brazil, Juruá River, Amazon basin

“…Spinipterus Akama & Ferraris, 2011 is a monotypic genus of Auchenipteridae, an inseminating family of Siluriformes known as driftwood catfishes. The auchenipterids represent a monophyletic family recognized by several features related to sexual dimorphism, such as the possession of an intromittent organ in mature males and modifications on the fins and maxillary barbel during reproductive season (Ferraris and Vari 1999, Birindelli 2014, Calegari et al 2014. The family currently comprises 120 species arranged in 22 genera (Eschmeyer et al 2018, updated), Spinipterus being the most recently described.…”

Taxonomic revision of the South American catfish genus Ageneiosus (Siluriformes: Auchenipteridae) with the description of four new species

“…Auchenipterids are exclusively Neotropical Siluriformes that are widely distributed in all major South American drainages (Ferraris, 2003). Currently, the Auchenipteridae includes 23 genera and c. 118 valid species (Ferraris, 2003(Ferraris, , 2007Rengifo et al, 2008;Sarmento-Soares & Martins-Pinheiro, 2008;Pavanelli & Bifi, 2009;Peixoto & Wosiacki, 2010;Ribeiro & Rapp Py-Daniel, 2010;Akama & Ferraris, 2011;Britski & Akama, 2011;Calegari et al, 2014;Walsh et al, 2015;Eschmeyer et al, 2016). Some species, particularly those of Ageneiosus Lacépède 1803, are commercially important.…”