Protozoan parasites of freshwater ornamental fish

The ornamental fish aquaculture represents a consolidated market worldwide. In Brazil, the major volume of commercialized freshwater ornamental fish is originated from fish farms managed by small and midsized farmers. The aim of this study was to characterize the metazoan parasitic fauna associated with the main freshwater ornamental fish farmed in Southern Brazil. Between July 2014 and January 2015, 423 fishes belonging to nine freshwater species were examined: angelfish Pterophylum scalare, siamese fighting fish Betta splendens, telescope and comet goldfish Carassius auratus, zebrafish Danio rerio, blood red swordtail Xiphophorus helleri, caramel and wagtail platy fish Xiphophorus maculatus, black molly Poecilia sphenops, white cloud mountain minnow Tanichthys albonubes and goldfinned barb Puntius sachsii. Water quality was measured in fishponds from each facility. Specimens were obtained from three ornamental fish farms located in three micro-regions in the State of Santa Catarina (Biguaçu, Camboriú e Joinville). Parasitological indexes were obtained after parasitological analysis of mucus, gills, and eyes. Trichodinids, Piscinoodinium pillulare, and Ichthyophthirius multifiliis were found in all fish farms analyzed. However, P. pillulare showed the greatest prevalence and mean intensity, compared to the other protozoa analyzed. 75% prevalence and mean intensity 57.5 were observed in the gills of P. scalare from fish farm Araquari. This study showed that fish farm Biguaçu, was the facility presenting the greatest parasite diversity. P. scalare and C. auratus were the most parasitized fish species presenting the higher richness when compared to another species. These ornamental species are widely traded and require greater care in cultivation because it is essential to produce healthy fish with attractive features accepted by the market.