ASTAXANTHIN OIL FROM ANTARCTIC KRILL IMPROVES GROWTH AND SENSORY CAUDAL PROFILE OF WHITE SHRIMP, Litopenaeus vannamei, REARED UNDER HYPERSALINE CONDITIONS  

Alberto J.P. Nunes*, Lena Burri, Otavio S. Castro
 
LABOMAR - Instituto de Ciências do Mar, Universidade Federal do Ceará, Avenida da Abolição, 3207 - Meireles, Fortaleza, Ceará, 60.165-081, Brazil. alberto.nunes@ufc.br

Despite the euryhalinity nature of Litopenaeus vannamei to tolerate a wide range of water salinities, shrimp performance is negatively affected by increased salt concentrations. A growth study evaluated the effect of dietary omega-3 polyunsaturated fatty acid (n-3 PUFA) levels on the growth performance of juveniles of L. vannamei. Diets were supplemented with 2.7% fish oil or astaxanthin krill oil at 1.5% (A2), 4.8% (A5.0), and 5.5% (A6) of the diet (as is basis), respectively. Dietary treatments were compared to a control group with 3.5% soybean oil. The oil is extracted from Antarctic krill (Euphausia superba) that is a swarming pelagic crustacean living in the Southern Ocean. The different treatment groups were reared under optimal (OWS; 23 ± 1.2 g/L) and hypersaline (HWS; 44 ± 2.0 g/L) water conditions. Moreover, shrimp tail fatty acid profile and consumer sensorial preferences (for control, fish oil, A5, and A6 tails) were evaluated.

After nine weeks of feeding, water salinity significantly affected only shrimp final body weight (P < 0.05). Shrimp grown under HWS reached a lower body weight compared to OWS (11.21 ± 2.01 g versus 11.56 ± 1.77 g). The astaxanthin oil diet (A5) promoted the best weekly growth (1.01 ± 0.01g), final body weight (11.97 ± 2.01g) and food conversion ratio (1.93 ± 0.3), regardless of water salinity. There were no significant differences on shrimp survival and shrimp yield among the experimental groups (P > 0.05). Shrimp tails fed diets with fish oil and the two highest astaxanthin oil concentrations (A5 and A6) revealed significantly increased n-3 PUFA levels, when compared to those fed the A2 and control diets. Both A5 and A6 inclusions promoted significantly higher consumer preference for color and flavor attributes. A minimum utilization of 5.0% of astaxanthin oil from Antarctic krill in L. vannamei diets improves shrimp growth performance and consumer sensorial preferences for shrimp tails. It also positively influences the n-3 PUFA content of shrimp tails.