The adductor mandibulae muscle complex in lower teleostean fishes (Osteichthyes: Actinopterygii): comparative anatomy, synonymy, and phylogenetic implications

Abstract

Bony fishes of the morphologically diverse infraclass Teleostei include more than 31 000 species, encompassing almost one‐half of all extant vertebrates. A remarkable anatomical complex in teleosts is the adductor mandibulae, the primary muscle in mouth closure and whose subdivisions vary in number and complexity. Difficulties in recognizing homologies amongst adductor mandibulae subdivisions across the Teleostei have hampered the understanding of the evolution of this system and consequently its application in phylogenetic analyses. The adductor mandibulae in representatives of all lower teleost orders is described, illustrated, and compared based on broad taxonomic sampling complemented by extensive literature information. Muscle division homologies are clarified via the application of a standardized homology‐driven anatomical terminology with synonymies provided to the myological terminologies of previous studies. Phylogenetic implications of the observed variations in the adductor mandibulae are discussed and new possible synapomorphies are proposed for the Notacanthiformes, Ostariophysi, Cypriniformes, Siluriphysi, Gymnotiformes, and Alepocephaloidei. New characters corroborate the putative monophyly of the clades Albuliformes plus Notacanthiformes (Elopomorpha), Argentinoidei plus Esocoidei plus Salmonoidei (Protacanthopterygii) and Hemiodontidae plus Parodontidae (Characiformes). We further confirm the validity of characters from the adductor mandibulae previously proposed to support the monophyly of the Esocoidei and the gonorynchiform clade Gonorynchoidei plus Knerioidei. © 2014 The Linnean Society of London

Gross morphology of the brain of Pseudopimelodus bufonius (Valenciennes, 1840) (Siluriformes: Pseudopimelodidae)

“…It is estimated that almost three-quarters of the total morphological information related to phylogenetic reconstruction is related to skeletal features (Wiley & Johnson, 2010). Datovo & Vari (2014) in a comprehensive review of morphological features used in fi h systematics, found a similar predominance of osteological characters (74%) in relation to other sets of data. According to those authors, 6% corresponded to myology, 5% to splanchnology, 14% to other morphological characters (e.g.…”

A digital dissection of two teleost fishes: comparative functional anatomy of the cranial musculoskeletal system in pike (Esox lucius) and eel (Anguilla anguilla)

“…The pars rictalis forms the ventro‐lateral portion, the pars malaris forms the dorso‐lateral portion, and the pars stegalis forms the medial portion. In some taxa, including Esox , the rictalis and malaris form a compound facial segment, the ricto‐malaris (Datovo & Vari, ). In Anguilla , the rictalis and malaris segments share a common origin, but are divided anteriorly into distinct parts (Datovo & Vari, ), and so are discussed separately here.…”

The brain of Brycon orbignyanus (Valenciennes, 1850) (Teleostei: Characiformes: Bryconidae): gross morphology and phylogenetic considerations

“…That was not what we found in our study, where the form of the brains has shown surprisingly variation among the examined taxa of Characiformes, having provided six phylogenetically useful characters. Thus, the CNS morphology in the Characiformes, as most probably also in other otophysan orders, is unquestionably worth exploring, as was the case for other non-osteological sources for morphological information (e.g., Datovo & Castro, 2012;Datovo & Vari, 2014). was financed by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) and RMCC was financed by Conselho Nacional Desenvolvimento Científico e Tecnológico (CNPq Proc.…”

“…During the last two centuries, diagnoses of fish taxa and hypotheses of their evolutionary relationships were almost exclusively based on osteological attributes (see Wiley & Johnson, 2010;Datovo & Vari, 2014). This extensive exploration of osteological features in bony fishes was really efficient in the delimitation of major Teleostei clades; notwithstanding, this almost exclusive focus on osteological features resulted in the "relatively minor attention" to other anatomical systems (Datovo & Vari, 2014), and very few studies have even tried to describe and analyze other major anatomical systems in fishes, such as the neuroanatomy, which according to Datovo & Vari (2014), based mostly on Wiley & Johnson (2010), represents approximately 1% of the synapomorphies currently recognized for teleosteans fishes.…”