A Comparative Study of Different Methods for Larval Selection on Survival Rate, Growth and Yield of Black Tiger Shrimp (Penaeus monodon Fabricius)

Abstract

      Since 2000, black tiger shrimp (Penaeus monodon) production in Thailand has decreased because of the slow growth syndrome, poor survival and lack of predictability of postlarval (PL) performance in the growout phase. To solve these problems, many criteria were developed to assess larval quality before stocking in the growout pond. In this study, three methods for selecting PL were compared: group 1 using the Shrimp Biotech method; group 2, the Wanachsunthorn method; and group 3, conventional method (control). The shrimp were raised in growout ponds (15 ponds for each group) with low saline (1-5 ppt) water at a density of 80,000 PL per rai (1,600 m²) for 120 days. The results showed that the yield and survival rates of shrimp in group 1 were 987.60±170.25 kg/rai and 67.91±10.54% compared with 882.86±136.36 kg/rai and 66.18±10.34% in group 2. There were no statistically significant differences between the two groups. However, there were significant differences in the production and survival rates in group 3 which were 491.53±81.06 kg/rai and 45.24±7.11%, respectively. The results from this study indicated that evaluation of several criteria in groups 1 and 2 gave a better quality of shrimp seed and were major factors affecting the survival rate and production of cultured shrimp.