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Anita M. Martinez <br />6 <br />by Tyus and Severson (1990). Larvae were not weighed for feeding rate adjustment <br />during the study because the initial diet fed was appro~dmately twice that used by Tyus and <br />Severson (1990) and Severson e# al. (1992). This increased feeding rate was intended <br />to prevent ration from limiting growth as experienced by Tyus and Severson (1990). <br />Rearing trays were cleaned every other day by gently pouring larvae from a dirty tray <br />(excess-feed and wastes generally adhered to the bottom) into a clean tray. <br />Twice during the study and upon its completion, larvae were counted and mortality <br />recorded. The position of the top three trays was rotated at this time to expose each tray <br />to any beneficial or deleterious impact that tray position may have had on larval <br />development. Five to ten larvae from each subse# were tranquilized with tricaine <br />methanesulfonate prior to each of nine examinations. Standard lengths, presence or <br />absence of food in the gut, onset and progression of fin and fin ray development, and any <br />deformities were recorded. <br />Results and Discussion <br />Growth and Survival <br />Composition of B-250 was comparable to that reported by Tyus and Severson <br />(1990) and Severson et al. (1992) (Table 1). Survival of larvae fed B-250 by these <br />investigators (78% and 96% respectively) was significantly higher than in the current <br />study (39%). The elevated survival reported by Severson et al. (1992) may have been due <br />to reporting survival after only 20 days. Similarly, reduced survival in this study appears <br />