Parasitological diagnosis in food fish produced in a fish farm, in the Zona da Mata, Minas Gerais, southeastern Brazil

Parasitological diagnosis in ornamental freshwater fish from different fish farmers of five Brazilian states

This study aimed to search parasites in 333 ornamental fish from five Brazilian states (Ceará, Minas Gerais, São Paulo, Paraná and Santa Catarina). Fish were sent from eight farms located in the municipalities of Fortaleza, Patrocínio do Muriaé, São Francisco do Glória, Cascavel, Timbó, Iguape, Jacareí and Mairinque. All fish received anesthesia earlier to euthanasia procedures. After the search for parasites, it was verified that 70.6% (235/333) of fishes were infected by at least one type of parasite, being 12 types of parasites identified: monogeneans, digenean metacercariae, cestodes, nematodes, Lernaea cyprinacea, trichodinids, Piscinoodinium pillulare, Ichthyophthirius multifiliis, diplomonad flagellates, Ichthyobodo sp., Chilodonella sp., and Tetrahymena sp. The proportion of infected fishes among the farms is compared through statistical tests, besides, animal handling adopted in each farm is also discussed. The importance of ensuring fish health in order to make the ornamental freshwater fish industry economically viable and reduce losses in production is highlighted.

Dermocystidium sp. infection in farmed striped catfish Pangasianodon hypophthalmus farmed in Ceará state, Northeastern Brazil

The genus Dermocystidium infects a wide range of animals. The host infection often occurs through the ingestion of endospores. The diagnosis depends on wet mounts and histopathological analysis of the affected tissue. The aim of this study was to investigate the incidence of Dermocystidium sp. infection on the skin of farmed striped catfish (Pangasianodon hypophthalmus) from a fish farm located in Fortaleza, Ceará state, northeastern Brazil. From these observations, we determined that 100% of the analyzed animals were infected with Dermocystidium sp. The wet mount and histopathology of the fish lesions revealed spore-filled cysts between the dermis and epidermis, encapsulated by connective tissue. Owing to a lack of research on the parasite and its prevalence among different fish species in Brazil and the rest of the world, additional studies are required to understand their endemicity in fish farms of Brazil, and consequently develop better disease prevention methods and increase the overall productivity.