Ontogeny and phylogeny in Trichomycteridae (Teleostei, Siluriformes): patterns in the development of morphological complexes

• Autor(a) principal: Reis, Vinícius José Carvalho
• Data de Publicação: 2023
• Tipo de documento: Tese
• Idioma: eng
• Título da fonte: Biblioteca Digital de Teses e Dissertações da USP
• Texto Completo: https://www.teses.usp.br/teses/disponiveis/38/38131/tde-17082023-144452/
• topic: Bagres; Catfish; Heterochrony; Heterocronia; Ontogenia; Ontogeny; Philogeny; Phylogenia; Trichomycteridae; Trichomycteridae

This thesis offers the first large-scale study on the ontogeny of the musculoskeletal system in Trichomycteridae and its implications for understanding the phylogenetic relationships and evolution of the family. Trichomycteridae is a monophyletic group of neotropical catfish with exceptionally rich morphological diversity. This diversity is reflected in a wide range of habitats and trophic niches. The feeding habits of the group vary from invertivores to strict hematophagy, the latter a unique case in Actinopterygii. Using developmental series and juvenile specimens representing most trichomycterid lineages, detailed descriptions of the development of various musculoskeletal systems of the head, such as the mandibular complex, opercular apparatus, branchial skeleton, suspensorium, and neurocranium are presented. Such information, new for the most part, provides a solid framework for formulating and testing hypotheses of homology, some of which representing long-standing controversies in Siluriformes, such as the supraoccipital, parietal, pterotic, extrascapular, and posttemporal. Observations also permit direct mapping of transformation sequences and connections between highly divergent conditions in adult specimens, such as the mouth apparatus of juveniles and adults of Vandelliinae. Results obtained are incorporated into new morphological and total evidence phylogenetic analyses with broader taxonomic and data density than previously available, allowing a detailed understanding of the diversification history of Trichomycteridae. Those results are combined with developmental information to provide an ontogenetic framework for testing a new method for detecting heterochronies designed to map paedo- and peromorphic phenomena in the family. The most relevant phylogenetic results are that Microcambevinae probably result from long-branched attraction, and the identification of a new clade composed of Stenolicmus ix and Ammoglanis pulex, previously assigned to Sarcoglanidinae, and the removal of Potamoglanis from Tridentinae. The synergism of phylogenetic hypothesis with ontogeny reveals wide-evolutionary patterns, showing that Trichomycteridae is a mostly paedomorphic family, a ground plan upon which numerous internested peramorphic apomorphies have evolved. One major event of miniaturization occurred at the base of a large clade, here named the miniature clade. Within that clade, there are various events of further reduction in size. Surprisingly, within the miniature clade there is also an event of reverse size-increase, a phenomenon detected not only by phylogenetic structure but also by marks left in the structure and development of different anatomical complexes.