1Fisheries Research Institute, Tokushima Agriculture, Forestry and Fisheries Technology Support Center, Kaifu, Tokushima 779-2304, 2Graduate School of Intergrated Arts and Sciences, Minamijosanjima-cho, Tokushima 770-8502, Japan
Migration and distribution of Muraenesox cinereus in the eastern Seto Inland Sea including the outer waters adjacent to the Kii Channel were estimated by mark and recapture experiments. A total of 3,117 individuals (44-3,200 g in body weight) were released in the periods of 1988-1992 and 2009-2010. All of the 359 recaptured fish (11.5%) except 3 found in other waters were captured within 1,112 days in these waters. Most of the tagged fish stayed around the release sites, but some migrated northward from the outer waters to the Kii Channel or Osaka Bay and migrated southward thereafter between April and December. None was recaptured between January and March. These results indicated that the habitat of M. cinereus in these waters extended from the eastern Seto Inland Sea to the outer waters. The migration route may have changed due to the rise of water temperature over a long period, or with different stages of growth.