Albendazole, levamisole and ivermectin are effective against monogeneans of Colossoma macropomum (Pisces: Serrasalmidae).

Abstract

This study evaluated the efficacy of albendazole, ivermectin, levamisole, mebendazole and praziquantel on monogeneans of Colossoma macropomum, based on in vitro and in vivo assays. In vitro assays indicated that albendazole (500, 100, 1,500 and 2,000mg/L), ivermectin (200, 250, 300 and 350mg/L) and levamisole (50, 75, 100 and 125mg/L) were 100% effective against Anacanthorus spatulatus, Notozothecium janauachensis, Mymarothecium boegeri and Linguadactyloides brinkmanni, while mebendazole (125, 150, 175 and 200mg/L) and praziquantel (5, 10, 15 and 20mg/L) were ineffective. Fish mortality in 24hr therapeutic baths with 500mg/L of albendazole was 6.6%, but the behaviour of the animals remained unchanged, while 200mg/L of ivermectin caused lethargy, signs of hypoxia and 100% mortality within 2hr, and 125mg/L of levamisole caused no mortality. The efficacy of 500mg/L of albendazole was 48.6% in the 24hr baths, while that of 125mg/L levamisole was 88.2%. Although ivermectin showed in vitro efficacy, the lowest concentration used in baths was highly toxic to fish. Therefore, we recommend the use of 125mg/L of levamisole to control and treat monogenean infestations on C.macropomum in fish farming.