| This study evaluated the in vitro and in vivo antiparasitic efficacy of formalin against Dawestrema cycloancistrium, the effects on the physiological response of Arapaima gigas and the residual action on fish muscle after 96h of exposure. As regards the in vitro assay, 0, 22, 44, 66, 88, 110, 330, 660 and 880 mg L-1 formalin were tested. After 1h of exposure to 660 and 880 mg L-1 formalin, there was a 100% mortality of D. cycloancistrium as well as after 2h of exposure at 330 and 110 mg L-1 and 3h of exposure at 44, 66 and 88 mg L-1. Concerning the in vivo test, when fish were exposed to formalin at 0, 220, 330, 440 and 550 mg L-1, there was 100% survival at all concentrations and exposure times evaluated. Baths of 1h with 440 and 550 mg L-1 formalin... |
