Eficácia de anti-helmínticos comerciais no tratamento contra monogenea das brânquias de Colossoma macropomum (Serrasalmidae)

Abstract

This study investigated the in vitro and in vivo anti-helminthic effects of albendazole, ivermectin, levamisole, mebendazole and praziquantel for the control of monogeneans of Colosoma macropomum gills (Tambaqui). In the in vitro assay, the efficacy of albendazole, ivermectin, levamisole, mebendazole and praziquantel in control of monogeneans Anacanthorus spathulatus, Notozothecium janauachensis, Mymarothecium boegeri and Linguadactyloides brinkmanni were tested using 4 concentrations and 3 replicates each. All concentrations of albendazole (500, 100, 1500 and 2000 mg / L), ivermectin (200, 250, 300 and 350 mg/L) and levamisole (50, 75, 100 and 125 mg/L) showed 100% efficacy, while the efficacy of mebendazole (125, 150, 175 and 200 mg/L) and praziquantel (5, 10, 15 and 20 mg/L) was caused by the DMSO diluent. However, in controls exposed to DMSO there was also 100% mortality of the parasites and in controls with water from the culture tank 100% mortality of the monogeneans occurred only after 6 h of exposure. From the in vitro results, the concentrations and best results for use in tambaqui therapeutic baths were determined. In the therapeutic baths, the fish were distributed in 4 treatments and exposed for 24 h at concentrations of 500 mg/L albendazole, 200 mg/L of ivermectin or 125 mg / L of levamisole. The concentration of 500 mg/L albendazole did not alter the behavior of exposed fish and mortality of fish was of 6.6%. However, 200 mg/L of ivermectin caused lethargy and signs of hypoxia in fish after 1 h and 100% mortality at 2 h of exposure, while levamisole 125 mg/L caused no mortality or behavioral change. After 24 h of the therapeutic baths, 500 mg/L albendazole had efficacy of only 48.6% against monogeneans and while levamisole had 88.2% efficacy. Although albendazole, ivermectin, levamisole, mebendazole and praziquantel demonstrated in vitro antiparasitic activity against monogeneans of the tambaqui, efficacy was observed only for albendazole and levamisole, but only levamisole is recommended in therapeutic baths as strategies to control the levels of monogeneans in the gills of tambaqui in fish farms