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60 JOURNAL OF APPLIED AQUACULTURE ~ Phase II (Day 26-52) Fish fed the A-250 diet had higher growth rates and were longer and heavier than those fed other diets (P < 0.05; Table 2). In addi- tion, survival of fish fed A-250 averaged 101%, while fish fed SCSS averaged 71 % (P < 0.05; Table 2). Growth and survival for fish fed the remaining diets was similar. Survival of over 100% in two replicates (102 and 108%) was presumably due to errors intro- duced in counting the small larvae. Phase III (Day 53-126) Although statistical analyses could not be performed on data col- lected during this phase because of the lack of replications, some preliminary inferences were drawn. Fish fed BioKyowa-A grew faster and had better survival than those fed other diets (Table 3). Fish maintained on SCSS were smaller, and survival (12%) was lower than in other treatments. Fish switched from A-250 to SCSS du{ing Phase III were small (30.5 mm average length), but their survival (97%) was high. Survival was also high (88%) in the group converted from SCSS to BioKyowa-A, and growth of these fish was higher than that of those maintained only on SCSS. The aver- age weight gain of the BioKyowa-A group converted to SCSS was greater (0.25 g) than that of those maintained on SCSS, but it was only about one-half that of those maintained on BioKyowa-A. All fish displayed a slow but steady weight gain during Phase I (days 5-25; Figure 1). During Phase II (days 26-52), the superior performance of the BioKyowa-A diet was apparent, and fish receiv- ing that diet exhibited steady growth to the end of the study.. Fish fed SCSS grew slowly in Phases II and III. The group converted from SCSS to BioKyowa-A in Phase III exhibited a rapid, ~teady growth rate beginning on day 72. Fish fed BioKyowa-A in Phase II and converted to the SCSS diet in Phase III continued growing after the change in diet but at a much slower rate. Thus, the superiority of BioKyowa-A was established early in feed trials, and it was appar- ent even with diet reversals. All diets were closed-formula feeds, and exact ingredients were unknown. Proximate analysis of the diets did not provide definitive information about why some performed better than others. ~iets