Evolutionary morphology and phylogeny of Serrasalmidae (Teleostei: Characiformes)

• Ano de defesa: 2024
• Autor(a) principal: Oliveira, George Vita de
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Biblioteca Digitais de Teses e Dissertações da USP
• Palavras-chave em Português: Anatomia; Anatomy; Miologia; Myology; Pacus; Piranhas; Sistemática; Systematics
• Link de acesso: https://www.teses.usp.br/teses/disponiveis/38/38131/tde-24102024-161004/

Pacus and Piranhas are members of the family Serrasalmidae, which is considered one of the most remarkable within Characiformesin terms of morphology, although it is still anatomically and phylogenetically poorly known. Some serrasalmids such as the pacus Colossoma and Piaractus are appreciated by fishing and fish farming, while other representatives such as the piranhas Serrasalmus and Pygocentrus are stigmatized for attacking bathers and fish in the sport fishing. Although there is as consensus on the monophyly of the Serrasalmidae, molecular and morphological proposals disagreed about the inner relationships of the family. Many genera such as Acnodon, Catoprion, Myleus, Myloplus, Pygopristis, and Serrasalmus, have a controversial positioning within Serrasalmeidae. A few studies about the skeletal musculature of serrasalmids were developed to date, most of them included few species and/or structures analyzed, and generally not involved a phylogenetic approach. Herein, 17 known genera of the Serrasalmidae were analyzed to perform a broad anatomical investigation about the skeletal musculature of the family, mainly on the facial myology. Two myological patterns were identified within Serrasalmidae, one showed by the subfamilies Colossomatinae and Myleinae, and other exhibited by the remaining representatives of Serrasalminae. Furthermore, several nomenclatural problems on the myology of the family were identified and resolved through the elaboration of a synonymic list. Myloplus rhomboidalis, a species that has a remarkable morphology among serrasalmids, has the diet, myology, osteology, and other structures of the soft anatomy investigated ontogenetically. The morphological modifications found in that species were correlated to the durophagous feeding habit. Data from the anatomical study of the Serrasalmidae were used to identify and assemble 78 phylogenetically informative characters from different myological complex, which were used to perform a phylogenetic analysis of the family. Overall, 46 species were analyzed, 38 of which were inner groups and eight were outgroups. The data recovered the monophyly of the family, with Metynnis luna as sister group of the remaining serrasalmids. Serrasalminae is considered paraphyletic and Colossomatinae and Myleinae are considered monophyletic in the present study.