Use of transmission electron microscopy and molecular techniques to study myxozoans

Abstract

Parasites of aquatic organisms are of considerable relevance, especially due to their impact on aquaculture systems and fisheries worldwide. In Brazil aquaculture is important due to the large fish production for food and ornamental aquariums. Some of the agents responsible for fish diseases are myxozoan parasites, which may cause significant economic losses, with high mortality ratios. Myxozoans are a group of parasitic cnidarians that have a complex life cycle including a vertebrate host, mainly fish, and an invertebrate host, usually annelids. Many myxozoans are still unknown to the scientific community, and their potential to cause disease in economically important fishes is undetermined. The Batalha River (São Paulo, Brazil) suffers anthropic action, has high diversity of fish species, and there is no other study being done in this river about the diversity of myxozoans. It offers abundant fish for human consumption and therefore it is important to study the parasite diversity of these fish. The aim of this study is to identify morphologically and molecularly myxozoan parasites detected in fish from the river Batalha in Brazil, by analysis of its ultrastructure and SSU rDNA sequencing. Furthermore, their pathogenic potential will be evaluated by histological sections of infected tissues. (AU)