A study on phylogeny, reproductive system, and spermatozoa in Plecoptera (Insecta)

• Ano de defesa: 2023
• Autor(a) principal: Gonçalves, Maisa de Carvalho
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Universidade Federal de Viçosa
• Palavras-chave em Português: Anacroneuriini; Plecoptera - Filogenia; Plecoptera - Morfologia; Análise cladística; Insetos aquáticos; Taxonomia dos Grupos Recentes
• Link de acesso: https://locus.ufv.br//handle/123456789/32189; https://doi.org/10.47328/ufvbbt.2024.071

A historical analysis of the phylogeny of Plecoptera is presented by reviewing the major phylogenetic studies of the order. The study aimed to conduct a morphologic cladistic analysis for Plecoptera, testing the monophyly of suborders, infraorders, and superfamilies proposed by the current classification using the principle of parsimony to resolve character distribution conflicts. Two sets of analyses were conducted. The first analysis recovered Systellognatha as monophyletic and did not confirm Antarctoperlaria and Euholognatha as monophyletic. Subsequent analyses identified Systellognatha as monophyletic and Antarctoperlaria as a sister group of Euholognatha, challenging the monophyly of Arctoperlaria. Despite extensive previous research, unresolved aspects persist regarding Plecoptera's phylogenetic relationships, particularly the need for additional characters. To address this, the study described, for the first time, the anatomy, histology of the reproductive system, and sperm morphology of the stoneflies of the tribe Anacroneuriini based on Neotropical fauna specimens. The male reproductive system of Anacroneuria and Kempnyia comprises a pair of medially fused testes, showing variations in testicular follicle numbers. Spermatogenesis in these genera is intermittent, suggesting readiness for mating upon emergence. Both genera exhibited long, filiform sperm with a distinctive head (acrosome and nucleus) and a flagellum. While Anacroneuria's sperm from males and females had reduced or absent acrosomes, Kempnyia's showed evident acrosomes but commonly detached nuclei from the flagella. Seminal vesicles in both genera housed spermatozoa bundles. These internal features—male and female reproductive systems, and sperm morphology—serve as valuable complementary methodologies. Keywords: Aquatic Insects; Stoneflies; Internal Anatomy; Internal Morphology; Taxonomy; Phylogenetic Systematics; Anacroneuriini.