Teflubenzuron as a tool for control of trichodinids in freshwater fish: Acute toxicity and in vivo efficacy.

In this study we describe the anti- Trichodina effects of teflubenzuron (TFB) for Oreochromis niloticus and for Piaractus mesopotamicus . We also evaluated the acute toxicity, for both species, by using TFB in the concentrations of 700.0, 800.0, 900.0 and 1000.0 mg L −1 and a control, without the drug. To assess the efficacy of TFB against Trichodina spp., we used the concentrations of 30.0 or 50.0 mg L −1 for one hour exposure in tilapia, and the concentration of 30.0, 50.0 and 80.0 mg L −1 for one hour and 50 mg L −1 for two hours exposures in pacu. Teflubenzuron did not present significant toxicity in either species, with LC50;48h > 1000.0 mg L −1 . The drug effectiveness was observed against four identified Trichodina species: T. magna, T. heterodentata , T. compacta and T. centrostrigeata , with 87.9% parasite reduction with one hour exposure to 50.0 mg L −1 TFB on O. niloticus and 96.1% with two hours exposure to 50.0 mg L −1 TFB on P. mesopotamicus . Teflubenzuron is a drug with potential to be used in Brazilian aquaculture; it attends to important requirements, such as low toxicity and high efficacy in controlling Trichodina spp. infection in O. niloticus and P. mesopotamicus . [ABSTRACT FROM AUTHOR]