Effectiveness of praziquantel in the control of the parasite Clinostomum complanatum Rudolphi, 1918 (Digenea, Clinostomidae) in fish of the species Rhamdia quelen Quoy & Gaimard, 1824 (jundiá)

Abstract

in Brazil the gender Clinostomum sp. has been subject of the studies due to the economical damages originated on account of the bad appearance of the fish for marketing. this paper’s purpose was to evaluate the effect of praziquantel medication in the treatment of the jundiá (Rhamdia quelen) fish sponged by Clinostomum complanatum. twenty one fish of the Rhamdia quelen species sponged by C. complanatum were selected and later they were separated in seven groups with three animals in each one. these animals were washed in a praziquantel solution dissolved in a tank with capacity for 300 liters of water in a concentration of 1 mg/l. in order to verify the noxious effect of praziquantel on the flukes, was stipulated periods of permanence of the fish of 1,2,5,10,15 and 20 hours within the product with evaluations realized in the days 6, 12 and 18 after the treatment. a significant reduction was observed in the number of cysts of the treated fish along the three accomplished evaluations and the fish submerged for 20 hours presented a parasites decrease of 100% after 18 days of treatment. the drug applied was effective in the struggle against the C.complanatum, however, the lesions of the tissue produced by the parasite’s death has served as an access way for secondary infections.