Effects of dietary astaxanthin and fish oil on maturation of pond-reared black tiger prawn Penaeus monodon

Abstract

This study was determine designed to the effect of dietary astaxanthin and/or fish oil on reproductive performance of pond-reared adolescent and broodstock black tiger shrimp penaeus monodon. This study was divided into two experiments. The first experiment studied effects of dietary astaxanthin on growth, survival and reproductive performance of pond reared immature black tiger shrimp p. monodon by using pelleted diets containing 3 levels of astaxanthin (0, 300 and 500 mg kg-1) Four months old, shrimp used in this experiment had no appearance of spermatopore or ovary development before the trial. The experiment was operated 120 days. No interaction between dietary astaxanthin and sex was found on growth, survival and astaxanthin accumulation. Weight gain of shrimp fed diet supplemented with astaxanthin 300 mg kg-1 had significantly higher (p<0.05) than those fed diet without astaxanthin. Female shrimp had significantly greater growth rate (p<0.05) than that of male. Survival rate of all groups was not significantly different (p>0.05) among levels of dietary astaxanthin and sex. Ovarian development did not appear in all treatments. Male shrimp fed diet supplemented with astaxanthin 300 and 500 mg kg-1 had significantly higher amount of spermatozoa (p<0.05) than those of the control. Shrimp fed diet supplemented with 500 mg kg-1 had significantly higher astaxanthin content in muscle and hepatopancreas (p<0.05) than those of other groups. In shell, shrimp fed diet supplemented with astaxanthin had significantly greater astaxanthin content (p<0.05) than those of the control. Sexes had not effect on astaxanthin content in all tissues of adolescent shrimp. The present study suggested that supplementation of astaxanthin to adolescent p. monodon diet could enhance reproductive performance in male shrimp. The second experiment studied the improvements for reproductive performance of pond-reared black tiger shrimp broodstock p. monodon by using diets containing 2 levels of fish oil, 3 and 8%. and 2 levels of astaxanthin 100 and 500 mg kg-1. Female shrimp weighting 48-50 g and male shrimp weighting 35-38 g were randomly separated to fed the experimental diets for 4 months. The result indicated no interaction between fish oil and astaxanthin, and fish oil and sex on average weight gain was found but astaxanthin and sex had significant (p<0.05) interaction. Fish oil was no effect on average weight gain. In male, shrimp fed high level of astaxanthin had significantly higher average weight gain (p<0.05) than those fed low level of astaxanthin. There was no interaction between fish oil and astaxanthin on amount of egg and spermatozoa. Shrimp fed diet containing high levels of fish oil and astaxanthin had significantly higher amount of eggs and spermatozoa than those fed diet containing low levels of them. No interaction was found on fish oil and astaxanthin, and fish oil and sex on astaxanthin content in all tissues. Astaxanthin content in all tissues was not significantly different among level of fish oil. Astaxanthin content in muscle, hepatopancreas, ovary and shell, only interaction between astaxanthin and sex was found. In muscle and ovary, shrimp fed diet containing high level of astaxanthin had significantly high astaxanthin content. In hepatopancreas, female shrimp fed diet containing high level of astaxanthin had significantly higher astaxanthin content than male shrimp. In shell, no significant difference among levels of fish oil, astaxanthin and sex was found on astaxanthin content. The interaction between fish oil, astaxanthin and sex was not found on fatty acid content in muscle, hepatopancreas and ovary. Shrimp fed diets containing high level of fish oil and astaxanthin had significantly high 22:6(n-3), total n-3 PUFA and total n-3 HUFA contents in muscle and ovary, whereas 20:4(n-6), 20:5(n-3), 22:6(n-3), total n-6 PUFA, total n-3 PUFA and total n-3 HUFA contents were significantly high accumulated in hepatopancreas of shrimp fed diet containing high level of fish oil. The supplementation of dietary fish oil and/or astaxanthin in practical broodstock shrimp diet could enhance reproductive performance of pond-reared broodstock shrimp.