Systematic and distribution of myxozoans collected in fish from Pardo River, middle Paranapanema River, State of São Paulo

Abstract

Parasites of aquatic organisms are of considerable relevance to study because of their impact on Aquaculture systems and fisheries worldwide and its biodiversity not yet known. Myxozoans are parasites that have a complex life cycle, parasitizing a vertebrate host, mainly fish, alternating with an invertebrate host, these annelids. Myxozoans are among the agents responsible for causing fish diseases and can cause major economic losses, with high mortality rates. Myxozoa taxonomy is traditionally done through morphological and molecular studies. Phylogenetic molecular studies for this parasite group make extensive use of ribosomal genes, especially the SSU rDNA, and often these genes are incipient in resolving group relationships. A new approach, such as phylogenomics through the use of Ultra Conserved Elements (UCEs), brings an analysis that is beginning to be used for this group of parasites. The systematics and phylogeography of invertebrates through the study of ultraconserved markers has recently been used to obtain genomic data capable of elucidating some relationships between species of the various families belonging to the Myxozoa. The present work aims to study the systematics, biodiversity and distribution of myxosporideans found in fish from Pardo River. The Pardo River is part of the Corumbataí-Botucatu-Tejupá Environmental Protection Area, created for sustainable management and environmental recovery actions in the region, as well as recharge areas of the Guarani Aquifer, the largest underground freshwater source in the world. For the study will be developed morphological analysis from light and electron microscopy, molecular analysis using traditional ribosomal markers and sequencing of new generation using UCEs. The phylogenetic relationships of myxozoans parasites of fishes from Rio Pardo and the general evolutionary context of this group will be analyzed based on the results obtained through sequencing. (AU)