Integrative Taxonomy, Molecular Systematics and Coevolution of Monogenoidea (Platyhelminthes) parasites of Doradidae (Siluriformes) endemic to the Neotropical Region

• Grant number: 22/15973-3
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Effective date (Start): December 01, 2023
• Effective date (End): November 30, 2025
• Field of knowledge: Agronomical Sciences - Fishery Resources and Fishery Engineering - Inland Water Fishery Resources
• Principal Investigator: Antonio Augusto Mendes Maia
• Grantee: Geusivam Barbosa Soares
• Host Institution: Faculdade de Zootecnia e Engenharia de Alimentos (FZEA). Universidade de São Paulo (USP). Pirassununga , SP, Brazil
• Associated research grant: 18/24980-8 - Myxozoa - cnidarians adapted to parasitismo: integrating different tools to investigate diversity, evolutionary history, development, and host-parasite interactions, AP.BTA.TEM

Abstract

Catfish of the family Doradidae (Siluriformes) are endemic to the Neotropics, with 96 valid species, most of them unique to freshwater, and occurring in all major river basins of South America. During the last decade, it has been postulated that members of the Doradidae are the sister group of the Auchenipteridae, and that these fishes are excellent models to investigate large-scale changes in Neotropical drainage patterns. Currently 19 species of monogenoids (Dactylogyridae) are known to parasitize doradid catfishes, distributed in the genera Cosmetocleithrum, Vancleaveus and Unibarra. Cosmetocleithrum species are mostly parasitic on doradids, but with some species occurring on Auchenipteridae hosts. However, only 9% of the valid doradid species have been investigated for monogenoid parasites. Nevertheless, in preliminary analyses of doradids collected in the Amazon, Caeté, Guamá and Prata river basins, we observed the occurrence of specimens of monogenoids of the family Dactylogyridae, suggesting that further study of these fishes will allow us to significantly extend the diversity of Monogenoidea parasitizing this fish family. In addition to advancing knowledge of diversity, the study of these parasites of doradids has potential for biogeographic and coevolutionary analyses, as it is reasonable to expect that these monogenoids accommodate evolutionary events associated with their hosts, as already reported in other parasite-host systems. Thus, this project aims to (1) recognize the diversity of monogenoid parasites of doradids, (2) propose phylogenetic hypotheses for the studied monogenoids, as well as test the evolutionary validity of their taxa by proposing taxonomic changes compatible with the results obtained, and (3) elucidate the coevolutionary and biogeographic processes responsible for the diversification patterns of the members of Monogenoidea parasiting doradids in South America. Fourteen doradid species of different lineages distributed in the Amazon, Caeté, Guamá and La Plata basins will be collected. The identification of the monogenoids will be based on morphological and molecular data (28S rDNA and COI genes). Partial DNA sequences of the genes RAG1, 12S and 16S of the fish hosts and of the genes 28S rDNA and COI of the parasite species will be used for phylogenetic reconstruction. Maximum likelihood and Bayesian inference phylogenetic trees of the host and parasite species will be built and used for analyses with the Procrustean Approach to Cophylogeny (PACo) and Jane, to evaluate the role of cospeciation in the diversification of these species, as opposed to duplication, loss and host-switching events.