Improved maturation of pond-reared, black tiger shrimp ( Penaeus monodon) using fish oil and astaxanthin feed supplements

Abstract

Penaeus monodon female (49 g) and male (37 g) shrimp were fed formulated diets supplemented with 3 or 8% fish oil and 100 or 500 mg kg − 1 astaxanthin, in addition to fresh squid during a 120 day trail using a 2 × 2 × 2 factorial design. Four formulated diets were provided with different combinations of high and low concentrations of lipid (fish oil) and astaxanthin. We found that fish oil addition, at the concentrations we used did not significantly ( P > 0.05) affect shrimp growth, but there was significantly greater growth of male shrimp and higher astaxanthin concentration. Female shrimp growth was not significantly different at either astaxanthin concentration. Likewise, there were no significant interactions on growth between fish oil and astaxanthin or fish oil and shrimp sex, but there was significant interaction between astaxanthin and sex of shrimp. Reproductive performance, as measured by number of eggs in gravid females and number of spermatozoa in male shrimp was significantly enhanced by both higher concentration of fish oil and astaxanthin. There was no significant interaction between fish oil and astaxanthin on number of eggs or spermatozoa. Likewise, there was no significant interaction between fish oil and astaxanthin, or fish oil and astaxanthin concentrations in shrimp muscle, hepatopancreas, ovaries or shell tissues. Astaxanthin concentrations in these respective tissues were similar for both levels of dietary fish oil. There were, however, significant interactions between astaxanthin and shrimp sex with these tissues. Greater dietary astaxanthin concentration resulted in significantly greater astaxanthin concentration in female shrimp muscle, hepatopancreas and ovarian tissues, but not in their shells. Female shrimp had significantly greater astaxanthin concentration in hepatopancreas tissue compared with males, but not in muscle or shells. Shrimp fed diets containing high levels of fish oil and astaxanthin had significantly greater 22:6n-3, total n-3 PUFA and total n-3 HUFA concentrations in muscle and ovary, whereas 20:4n-6, 20:5n-3, 22:6n-3, total n-6 PUFA, total n-3 PUFA and total n-3 HUFA concentrations were significantly greater in hepatopancreas of shrimp fed diet containing high level of fish oil. We concluded that dietary supplementation of formulated diets with 8% fish oil (12% total lipid) and at least 280 mg kg − 1 astaxanthin will significantly improve Penaeus monodon maturation and spawning success.