Teleostean Phylogeny Based on Osteological and Myological Characters

Abstract

Despite the progresses done in the field of teleostean phylogeny in the last decades, recent studies continue to raise questions concerning the higher-level relationships of this remarkably diverse group of fishes. The main aim of the present work is to help to clarify teleostean higher-level relationships. For that purpose, we undertook a cladistic analysis including 70 terminal taxa of 20 different orders and 271 morphological characters, concerning mainly osteological and myological structures of the cephalic region, pectoral girdle and fins and anterior vertebrae. In the consensus cladogram obtained, the elopomorphs appear as the most basal extant teleosts. The osteoglossomorphs included in the analysis are grouped in a monophyletic clade, which is the sister-group of the remaining non-elopomorph teleosts. The Otocephala, the Clupeiformes, and the Ostariophysi appear as monophyletic clades, thus contradicting the results of some recent molecular cladistic analyses placing the Alepocephaloidea inside the Otocephala. In fact, the monophyly of the Argentiniformes (Alepocephaloidea + Argentinoidea) is well supported by the cladistic analysis of the present work. This cladistic analysis also provides support for the monophyly of the Alepocephaloidea, of the Argentinoidea, of the Galaxioidea + Osmeroidea, and of the Esociformes. However, it does not provide strong evidence to resolve the relationships between the Argentiniformes, Salmoniformes, Esociformes, Osmeriformes and Neoteleostei, although it does indicate that the salmoniforms might be closely related to the Neoteleostei and that the Esociformes and the Osmeriformes might constitute a monophyletic unit. The monophyly of the Cypriniformes + Characiformes + Gymnotiformes + Siluriformes, of the Characiformes + Gymnotiformes + Siluriformes and of the Gymnotiformes + Siluriformes is well supported.