紀伊水道からのトラフグ当歳魚の回遊と回遊に及ぼす冬季の低水温の影響

抄録

Mark and recapture experiment of young-of-the-year ocellate puffers (≦500g BW) were carried out in the Kii Channel by longline fishermen of Tokushima Prefecture during December in 1990 to March in 1991 and during November in 1991 to March in 1992. Two hundred ocellate puffers were recaptured in the Seto Inland Sea, Pacific Ocean, East China Sea, and Sea of Japan. Most of the puffers but one migrated to the western waters of Seto Inland Sea. They migrated southward to Tosa Bay on the Pacific coast during February to March when water temperature at 20 m depth in the Seto Inland Sea was below 10°C, In other months they migrated westward through the Seto Inland Sea. Only one ocellate puffer migrated eastward and recaptured in Kumano-Nada Sea. These results indicated that the migration range of ocellate puffers tagged in the Kii Channel extends from the waters around Shikoku Island to the East China Sea including waters of western Sea of Japan. This ocellate puffer population seems to be independent from the one in Ise Bay and Mikawa Bay on the Pacific coast of central Japan.