Case report of Monogênea parasitism in the ornamental fish Polypterus palmas in Brazil

Abstract

The ornamental fish trade is characterized by the aggregation of a number of species of several places of the world. The translocation of ornamental fish can carry pathogens that may pose a risk to unaffected regions. Gyrodactylus parasite, flatworm of the Monogenea class, is categorized by its rapid multiplication. Polypterus palmas species acquired from a quarantine accredited to import have been maintained in a battery of tanks in retail commercial establishments in Brazil, and exhibited signal loss of mucus and parasites perceptible by the naked eye. Animals were moved to hospital tanks and treated with Praziquantel, and the parasites were observed in an optical microscope. After microscopic analysis, the wet mount showed a Monogenea, suggestive of Gyrodactylus sp. Subsequent to diagnosis, the battery aquariums were treated with Trichlorfon in a single dose as a preventive measure, which proved to be toxic to some species of fish. Studies involving the health conditions of ornamental fish commercialized in Brazil should be developed to elucidate the dynamics of some diseases in different species. New studies as well as the acting of trained professionals in applying self-control systems could reduce the spread of diseases and contribute significantly to health and welfare of ornamental fish.