A Influência dos parâmetros físico-químicos da água na abundância parasitária de monogenea em híbrido Patinga (Piaractus mesopotamicus x Piaractus brachypomus)

Abstract

Considering the lack of studies on the parasite/host/environment relationship involving hybrid fish, the objective of this work was to evaluate the abundance of Monogenea Class representatives in gills of hibrid Patinga (Piaractus mesopotamicus x Piaractus brachypomus) and to correlate the parasitic abundance with physicochemical parameters of water and condition factor (Kn) in three commercial fish farms in the Grande Dourados region. Were evaluated 56 specimens of the patinga hybrid were collected between October/2017 and June/2018. The physicochemical parameters of water were measured before each collection in the properties and subsequently correlated with parasitic abundance of fish. In general, only 2 of the 56 specimens examined were not parasitized, totaling 10,670 specimens of monogenea found in the other fish. Only the water transparency presented significant difference when compared between the three properties, where by Tukey test, it was observed that the difference was between the properties “B” and “C” (p = 0.01). In property “A” strong positive correlation for transparency was observed. In property “B” there was a positive correlation for pH and conductivity and negative for dissolved oxygen. Regarding the property “C”, a negative correlation was observed between the biometric parameters. No significant correlation was observed between Kn and parasitism abundance in any of the properties.