1. Port of Nagoya Public Aquarium, 1-3 Minato-machi, Minato-ku, Nagoya, Aichi 455-0033, Japan
2. Cooperative Department of Veterinary Medicine, Gifu University, 1-1 Yanagido, Gifu, Gifu 501-1193, Japan
3. Department of Veterinary Pathobiology, Nihon University College of Bioresource Sciences, 1866 Kameino, Fujisawa, Kanagawa 252-0880, Japan