Effect of increasing DHA content in new weaning diets for longfin yellowtail (Seriola rivoliana)

Abstract

The present study evaluated the effect of increasing levels of docosahexaenoic acid (DHA) in new weaning diets for Seriola rivoliana. Five different diets with the same proximate composition and different DHA content [0, 15, 30, 40 and 50 g kg−1 dry weight (DW)] were formulated. Each diet was fed to S. rivoliana larvae from 30 to 45 dah in three replicate 200-l tanks. Larval mortality was daily recorded, while larval growth and histological evaluation was assessed initially (30dah), medium (37dah) and end (45dah) of the feeding test. At the end of the feeding period, larvae weaned with diets with highest DHA levels showed better final survival and resistance to stress test (air exposure) while nor growth neither fresh or dry weight were affected by DHA content in the weaning diet.