Comparison of survival and larvae physiological resistance of white shrimp, Litopenaeus vannamei, fed with live food (rotifer and Artemia urmiana) and concentrated food
Anemia nauplii and rotifier are considered as the most important live food in aquaculture because of their high nutritional quality, suitable size and mobility. The survival rate and resistance of white shrimp (Litopenaus vannamei) postlarvae fed by Artemia urmiana, Brachinus plicatilis and concentrated food were investigated. Larvae at the stage of Protozoae 1 were stocked in 14 liters plastic containers filled by 6 liters of water. There were 75 larvae per liter in each container. The larvae were fed in 3 treatments: T1 (rotifier), T2 (Artemia) and T3 (concentrated food). Each treatment was repeated 3 times and used during Protozoae 1 (PLC} to Post-larvae 5 (PLO stages. Data analysis was done through Duncan Test. We observed that from Mysis 1 stage to PL1 the rotifier can be used for shrimp feeding and from this stage to PL5, Artemia nauplii can be used as food for the larvae. To evaluate the quality of larvae, the physiological resistance tests were conducted against formalin and salinity in different periods of time (30, 60 and 90 minutes). We found that at the PLC stage, the maximum survival (100%) in formalin tests (I 0Oppm) and (200ppm) and salinity test (15ppt) was related to feeding the shrimp larvae with rotifier. However, at the PL5 stage, the maximum survival (100%) under the same conditions was related to application of Artemia nauplii food. The concentrated food showed the minimum survival in all tests
