We performed four sets of feeding trials to establish optimum feed size (Exp-I), stocking density (Exp-II) and feeding frequency (Exp-III and IV) for Korean rockfish. In Exp-I, three different particle sizes of a commercial diet (small, 2.0-2.1 mm; medium, 2.4-3.2 mm; and large, 4.0-5.3 mm) were fed to four replicate groups of fish (22.8±0.1 g), each of which was fed to apparent satiation for six weeks. In Exp-II, fish (44.3±0.4 g) were reared at four stocking densities (1.5, 3.0, 4.5 and 6.0 kg/m 3 ) and fed a commercial diet to apparent satiation for four weeks. In Exp-III, fish (14.8±0.1 g) were fed a commercial diet once, twice, thrice, 4× or 5× a day at a feeding ratio of 3.25% of body mass. Another group of fish was fed the same commercial diet 5× a day to apparent satiation; this treatment was designated FS (five times satiation/day). In Exp-IV, fish (31.3±0.1 g) were fed a commercial diet once, twice, thrice or 4× a day to apparent satiation. Another group of fish was fed to apparent satiation once every 48 hours. In Exp-I, fish fed the large particle (4.0-5.3 mm) diet had a significantly higher feed conversion ratio and lower protein efficiency ratio than fish fed the small particle diet. In Exp-II, groups of fish reared at densities of 4.5 and 6.0 kg/m 3 had significantly higher feed intake and growth performance than fish reared at 1.5 and 3.0 kg/m 3 . In Exp-III, fish fed to apparent satiation had significantly higher growth performances than fish fed once or 4× a day. A significantly higher feed conversion ratio and a lower protein efficiency ratio were obtained in the FS group. In Exp-IV, growth performance and feed utilization efficiency were not significantly affected by experimental variation in feeding frequency. Fish fed to apparent satiation once every 48 hours had better feed utilization than those in other treatments and growth performances of those were comparable. Therefore, the optimum feed particle size, stocking density and feeding frequency for Korean rockfish under conditions we used were 2.0-3.2 mm, 4.5-6.0 kg/m 3 , and once a day or once every 48 hour, respectively.

A set of 72 microsatellite markers distributed evenly among 24 linkage groups were selected from the published genetic linkage maps of Japanese flounder Paralichthys olivaceus. In two normal diploid full-sib families, the test for Mendelian inheritance showed that genotypic segregation deviations were not significant at all analysed loci. To estimate microsatellite-centromere map distances, four meiotic gynogenetic diploid lines were produced by the activation of eggs using UV irradiated sperm of red seabream Pagrus major and cold-shock treatment to block the extrusion of the second polar body. Under the assumption of complete interference, 21 markers were located in the centromeric region, 39 in the telomeric region and the rest in the intermediate region of linkage groups. A total of 192 mitotic gynogenetic diploids from one spawn were identified by these markers. Genotype analysis showed that the number of homozygous individuals decreased as microsatellite-centromere map distance increased on each linkage group.

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