| Popis: |
Indoor nursery systems are becoming increasingly popular for high-quality whiteleg shrimp production. These systems allow for a significant degree of control and management in a biosecure manner. However, it is still unclear as to what type of production system is best suited for indoor whiteleg shrimp nurseries. This study evaluated and compared clean-water recirculating aquaculture system (CW-RAS), photo-heterotrophic (PT), and biofloc technology (BFT) systems in terms of water quality, growth performance, and production costs of whiteleg shrimp Litopenaeus vannamei at three stocking densities (500, 1000 and 1500 org/m3) for 35 d in the nursery phase. In this study, twenty-seven, 100-L circular plastic tanks (microcosm) were randomly assigned to one of the treatments and stored with postlarvae shrimps (0.016 g). Throughout the experiment, water quality parameters remained within acceptable ranges for whiteleg shrimp growth. High concentrations of total ammonia-nitrogen (TAN) were determined in the CW-RAS system and nitrates and nitrites in the BFT system. Furthermore, the growth parameters showed significant differences (P < 0.05) between the treatments; higher values in PT and BFT systems at 500 org/m3 and lower survival in the CW-RAS system. These results suggest that a dense-dependent effect was observed from 1000 org/m3 onwards. In general, postlarvae, feed, labor and energy accounted for higher costs. The study findings further indicate that CW-RAS had the highest production costs for 1000 juveniles. |
