1Meiji Seika Pharma Co., Ltd., Chuo, Tokyo 104-8002, 2Kumamoto Prefectural Fisheries Research Center, Kamiamakusa, Kumamoto 869-3603, 3Kumamoto Prefectural Fisheries Development Division, Chuo, Kumamoto 862-8570, 4Tokyo University of Marine Science and Technology, Minato, Tokyo 108-8477, Japan
Febantel was developed as an oral anti-parasitic agent against monogenean Heterobothrium okamotoi for farmed tiger puffer Takifugu rubripes. In aquaculture, febantel might be used for the same fish repeatedly to obtain good anti-parasitic effects in fish farms. In this study, we investigated the safety of febantel for tiger puffer when used repeatedly. We also investigated the impact of febantel on the marine environment. Febantel was administered to fish at 25 mg and 50 mg per kg of body weight for five days and the process was repeated after a 14-day pause. External and internal clinical signs were investigated in tiger puffer as well as hematological parameters. During the examination period, tiger puffers showed no decrease in appetite or changes in growth pattern compared with the control group. In addition, we observed the effect of febantel on diatoms (Skeletonema costatum), crustaceans (Artemia salina), and fishes (Pagrus major) as proxies for marine organisms. The results confirmed no influence on the tested organisms. These results suggest that febantel is safe for tiger puffer and has no toxic effects in marine organisms.