اثر سطوح رنگدانه آستازانتين بر ساخصهاي رشد و درصد بازماندگي ميگوي پاسفيد جوان (Litopenaus vannamei)

The Effect of Dietary Levels of Astaxanthin on Growth Indices and Survival Rate of Whiteleg Shrimp {Litopenaeus vannamei)

The effect of different levels of astaxanthin was evaluated on the growth indices and survival rate in whiteleg shrimp (Litopenaeus vannamei) of 17.39 ±0.04g average weight. The experiment was conducted on the basis of a completely randomized design (CRD) with four dietary treatments (0, 50, 100 and 150 mg/kg levels of astaxanthin) in three replications. The shrimp was fed four times daily for 9 weeks at average water temperature of 28 ±2 °C, dissolved oxygen 7 ± 0.05 mg/1, salinity 41 ± l%o and pH 8.1 ± 0.02, and natural photoperiod regime. Results showed statistically significant differences in weight gain (WG), specific growth rate (SGR), condition factor (CF) and FCR in different treatments compared to the control group. There were no significant differences in biomas, hepatosomatic index (HSI) and survival rate in the different treatments. Diet containing l00mg/kg astaxanthin showed the highest WG (4.85 ± 0.14 g), SGR (0.39 ± 0.01), CF (0.95 ± 0.02) and the best FCR (1.88 ± 0.07) compared to other treatments (P< 0.05), but didnʹt significantly differ from 50mg/kg treatment. It can, therefore, be concluded that 50mg/kg diet was the best one in terms of growth performance due to the economic advantage.