抄録
Two types of clones of the ayu Plecoglossus altivelis heterozygous and homozygous clones, were produced by crossing second generation gynogenetic diploids with sex reversed clones of a different or the same line, respectively. Samples of these fish, together with normal control diploids, were used in this study to monitor the expected reduction of the genetic variance in the clonal lines. The morphological traits measured (body weight, fork lengtht and gonad weight) showed a significant reduction of the coefficient of variation (C. V.) of 44.8% on average (heterozygous clones 56.17%, homozygous clones 33.4%). Furthermore, from all the physiological traits evaluated, hematocrit, plasma glucose, and mean corpuscular hemoglobin concentration (MCHC), also showed a significant variation reduction of 42.33% (average) for the heterozygous clones and 13.4% (average) for the homozygous clones. An estimation of the heritability of both kind of traits is proposed, based on a substantial elimination of the genetic variation in the clonal lines.
