Knodus borki sp. n. - ein neuer Salmler aus Peru mit einer ergänzenden Beschreibung von Boehlkea fredcochui Géry, 1966 (Teleostei: Characiformes: Characidae)

Abstract

A new Characid fish – Knodus borki sp. n. – is described from the surroundings of Iquitos in Peru. Knodus borki sp. n. is distributed as Boehlkea fredcochui GÉRY, 1966 since many years by aquarium trade. Both species differ mainly in the dentition of maxillary bone (three to four tricuspid or conical teeth in Knodus borki sp. n. vs. 11 to 21 tricuspid and conical teeth in Boehlkea fredcochui) and in colouration. Knodus borki sp. n. is closely related with Knodus megalops MYERS, 1929. Both species differ (1) in lateral line (incomplete in Knodus borki sp. n. vs. complete in Knodus megalops), (2) in the size of eye (2,46–3,24 times SL in K. borki sp. n. vs. 2,2 times SL in K. megalops), (3) in body depth before dorsal fin (2,91–3,34 times SL in K. borki sp. n. vs. 2,9 times SL in K. megalops), (4) in head length (3,94–4,65 times SL in K. borki sp. n. vs. 3,8 times SL in K. megalops) and (5) in the colouration.

New and poorly known Characiform fishes (Teleostei: Characiformes: Characidae) from French Guyana. A new Tetra of the genus Bryconamericus

“…There are authors which accept Knodus as a valid genus (e.g. GÉRY, 1978;LIMA et al, 2004;ZAR-SKE & GÉRY, 2006;FERREIRA & LIMA, 2006;FERREIRA & CARVAJAL, 2007;ZARSKE, 2007ZARSKE, , 2008VARI et al, 2009, and others) and authors which do not accept Knodus (THAPHORN, 1992;ROMAN-VALENCIA, 2003, 2005. Here we accept Knodus because the phylogenetic relationships of the whole old Tetragonopterinae is not solved and if we do not accept the differentiation between Bryconamericus and Knodus so we also can not accept for example the differentiation between Astyanax and Moenkhausia or Hyphessobrycon and Hemigrammus.…”

Revision of Bryconamericus (Characiformes, Characidae) from Pacific coastal and Amazon River drainages with descriptions of three new species

“…Today however, it is generally accepted that these genera are distinct. Ferreira & Lima (2006), Zarske (2008), Ferreira & Carvajal (2007), Ferreira & Netto-Ferreira (2010), Román-Valencia et al (2013a), Esguicero & Castro (2014), Mirande (2018), Menezes & Marinho (2019) and Anjos de Sousa et al (2020) treated Knodus as valid as diagnosed by Eigenmann (1927), defined by a combination of characters, such as complete lateral line, four teeth on inner premaxillary series, and differing from Bryconamericus in the type of caudal squamation; in accordance with Menezes & Netto-Ferreira (2019), very likely that many of species identified as Knodus or Bryconamericus correspond to Rhinopetitia species. Mirande (2018) recognized the clades Knodus and Diapoma (including some species of Bryconamericus) within Diapomini.…”

A new species of Hemibrycon (Teleostei: Characiformes: Characidae) from the Roble River, Alto Cauca, Colombia, with a key to species known from the Magdalena - Cauca River Basin

“…Even so, Hemibrycon has traditionally been distinguished from Bryconamericus by only this character (Román-Valencia, 2001) and recently this character was also used by Malabarba & Weitzman (2003) to distinguish Hemibrycon from Cyanocharax. Arcila-Mesa (2008) found Bryconamericus to be the sister genus to Hemibrycon based on three synapomorphies: modifi cations of the jaws and suspensorium and the shape of the scales of the caudal fi n. The genus Hemibrycon Günther has been shown to be monophyletic based on four synapomorphies: presence of ectopterygoids with widened ventral anterior projection, four to six times wider than posterior part; a red spot present in life on ventral margin of caudal peduncle; a postero-ventral projection on the pterotic and fi rst infraorbitals gradually decreasing in width from posterior tip and located near posterior part of antorbital (Arcila-Mesa, 2008); its taxonomy is fairly well known 2009a;b;c;2010a;b;Román-Valencia & Ruiz-C., 2007;Bertaco et al, 2007;Román-Valencia & Arcila-Mesa, 2008;2009;2010;Zarske, 2008). H. dentatus from upper Cauca River and H. decurrens from the lower Magdalena River have been shown to be synonyms of B. caucanus (Román-Valencia et al, 2009a).…”