Effects of salinity and dietary carbohydrate levels on growth and energy budget of juvenile Litopenaeus vannamei

The culture of Litopenaeus vannamei in low-salinity waters is now popular in many regions of the world. A 6 x 3 factorial experiment was conducted to determine the effects of salinities (tap water, 1parts per thousand, 2parts per thousand, 4parts per thousand, 8parts per thousand, and 16parts per thousand) and dietary carbohydrate levels (15.47%, 29.15%, and 41.00%) on survival, growth, food consumption, food efficiency, absorption efficiency, and energy budget of juvenile L. vannamei. The results showed that no shrimp survived in tap water at the end of the experiment irrespective of dietary carbohydrate (CBH). At each dietary CBH level, the specific growth rate (SGR), food consumption, and food efficiency generally increased with increasing salinity within the range of 1-16parts per thousand. At salinities of 1parts per thousand, 2parts per thousand, 4parts per thousand, 8parts per thousand, and 16parts per thousand, optimal CBH levels corresponding to maximum SGR decreased with increasing salinity and were 29.87%, 27.59%, 26.85%, 26.25%, and 22.29%, respectively. At 1-8parts per thousand, the percentage of consumed energy deposited in growth (%C) was significantly higher in shrimps fed 29.15% CBH as compared with other treatments, whereas at 16parts per thousand, the significantly higher value was in those fed 15.47% CBH.