Evaluation of diet supplements to formulated diet for intensive culture of smallmouth bass, Micropterus dolomieu, fry.

摘要

This study examined the use of three dietary supplements - two commercial feeding stimulants and natural zooplankton - to improve survival of intensively cultured smallmouth bass, Micropterus dolomieu, fry fed a commercial dry diet (Biokyowa B400; BK). The four treatments were BK, BK and a supplemental solution of krill hydrolysate (BK-KH), BK and Revolution (BK-REV), and BK and frozen zooplankton collected from a nearby pond (BK-ZP). At the end of the 30-day culture interval, differences in treatment means for total length and mortalities that were not accounted for were not statistically different (NS, P>0.05). Survival was 17% for BK-KH and 19.8% for BK-REV treatments (NS), and they were significantly lower than the 44.7 and 41.6% survival for BK-ZP and BK treatments, respectively. Viability is the percent of live fish without apparent deformities at the end of the 30-day culture interval. For BK-ZP and BK treatments, viability was 36.1 and 29.6%, respectively. These values were not significantly different from each other, but both were significantly higher (P>0.05) than viability of the BK-KH (16.1%) and the BK-REV (16.3%) treatments. Compared with previous research at this facility and published data of others, the study demonstrated improved survival and viability for intensive culture of smallmouth bass in the first 30 days on a formulated diet. Diet costs among the four treatments ranged from 4 to 13 cents per viable fry, with the lowest cost for BK-fed alone.