1. Daiichi College of Pharmaceutical Sciences, Fukuoka 815-8511, Japan
2. School of Marine Biosciences, Kitasato University, Ofunato, Iwate 022-0101, Japan
3. Bureau of Fisheries and Aquatic Resources, 860 Arcadia Building, Quezon Avenue, Quezon City 1100, the Philippines
4. Faculty of Fisheries, Kagoshima University, Kagoshima 890-0056, Japan