Juvenile Penaeus monodon produced from a concrete nursery tank system (at the Tinsulanonda Songkhla Fisheries College in Thailand) at a range of stocking densities were ongrown in net cages at a common stocking density (125/m<sup>2</sup>) to examine the effects of nursery rearing conditions on their subsequent ongrowing performance. Five replicated groups of 1000 juvenile shrimps nursed at 4 different stocking densities in concrete nursery tanks and one density in net cages were stocked into ten 8-m<sup>2</sup> net cages located in brackishwater ponds and ongrown for 10 weeks. Results suggested that small juvenile shrimp produced from concrete nursery tanks stocked at high densities (up to 1000/m<sup>2</sup>) showed high specific growth rates of up to 7% of body weight/day. This increased growth allowed these shrimp to compensate for previous stunting, within 1 month of subsequent ongrowing when compared with large juveniles produced from low density (125/m<sup>2</sup>) nursery tanks ongrown under similar conditions. Juvenile shrimp produced in concrete tank nurseries at moderately high densities (500/m<sup>2</sup>) performed significantly better than those produced from net cage nurseries stocked at similar densities when subsequently ongrown in net cages. Shrimp growth rates thus seem to be determined not only by initial shrimp size, age or ongrowing conditions, but also by conditions encountered during their nursery culture. This result indicates the advantages of intensive nursery tank systems yielding high quality, fast-growing juvenile shrimp.
The effects of nursery rearing postlarval Penaeus monodon at different densities on their subsequent ongrowing performance in net cages. Project Technical Report, University of Stirling, UK,