Development of five tiger puffer species of the genus Takifugu was investigated from artificially inseminated eggs to 150-180 days young fishes. Growth rate in the period was large in the order of T. stictonotus, T. pardalis, T. snyderi, T. niphobles and T. poecilonotus. Biting behavior was observed strongly during juveniles in the order of T. pardalis, T. snyderi and T. poecilonotus but not in T. niphobles and T. stictonotus. Panicking behavior against human was observed in young fishes of T. poecilonotus and T. snyderi.