Metazoários parasitos de Synbranchus marmoratus (Acnopterygii, Synbranchiformes, Synbranquidae) capturados no Pantanal de Mato Grosso do Sul, Brasil​

• Ano de defesa: 2024
• Autor(a) principal: Leonardo França do Nascimento
• Orientador(a): Fernando Paiva
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Fundação Universidade Federal de Mato Grosso do Sul
• País: Brasil
• Palavras-chave em Português: 1; 2; 3
• Link de acesso: https://repositorio.ufms.br/handle/123456789/8337

The fish Synbranchus marmoratus, known as "mussum," belongs to the family Synbranchidae and the order Synbranchiformes. Despite not being a species of great commercial interest, studies of this nature are important to assist in understanding the relationships between metazoan parasites and their hosts. Through morphological studies, five major groups of metazoans were identified: Pentastomida (Sebekia sp.), Nematoda (Brevimulticaecum sp., Eustrongylides sp., Camallanidae, and Capilaridae), Cestoda (Proteocephalidae), Trematoda (morphotype Neascus and Clinostomum sp.), and Myxozoa (Myxobolus sp.). Pentastomida Sebekia sp. was the most prevalent (35%), found in 14 hosts with an average abundance of 0.90±3.34. Neascus sp. showed the highest abundance, parasitizing 5% of the hosts. Nematodes presented the highest morphotype richness with four reported groups: Brevimulticaecum sp., Eustrongylides sp. larvae, adults of Camallanidae gen. sp., and Capillaridae gen. sp. Additionally, molecular analyses were performed on Eustrongylides sp. larvae and specimens of the family Camallanidae. The morphological similarity of Eustrongylides sp. larvae to E. tubifex larvae was observed due to the presence of papillae with spiniform apices in the inner circle. However, sequences were compared to those of E. ignotus and E. excisus, and the sequence obtained in this study was closer to other undetermined species of the genus Eustrongylides. For Camallanidae specimens, despite phylogenetic analysis not grouping the obtained sequence with three other genera in the family, morphological analysis indicated that the present species is within the Camallanidae family, emphasizing the need to collect new samples to describe a new species in the family. The studies presented in this dissertation highlight the need for more data on the metazoan parasites of S. marmoratus since literature focusing on these hosts is scarce. Due to its commercial value in sport fishing, this knowledge can be of great value for a better understanding of the richness of metazoan parasites in freshwater fish.