Aquaculture Studies 2019, Vol 19, Num, 1     (Pages: 45-56)

Effects of Nursing Methods, Astaxanthin Supplementation and Water Quality on the Survival of Blue Swimming Crablets (Portunus pelagicus, Linnaeus, 1758)

Anawat Boonyapakdee 1 ,Ram Chandra Bhujel 1

1 Aquaculture and Aquatic Resources Management, Department of Food, Agriculture and Bio-resources School of Environment, Resources and Development, Asian Institute of Technology, 58 Moo 9, Km. 42, Paholyothin Highway Klong Luang, Phatum Thani, 12120 Thailand DOI : 10.4194/2618-6381-v19_1_05 Viewed : 954 - Downloaded : 775 The present research investigated the effects of nursing on blue swimming cablets (Portunus pelagicus Linnaeus, 1758) between Cup and Substrate methods for 35 days on the survival and growth with and without astaxanthin supplementation. Four treatments (Cup + Asta), (only Cup), (Substrate + Asta) and (only Substrate) were replicated three times in plastic tanks (500 L). Growth performance and the water quality parameters were monitored weekly. Results showed that there was no significant difference (P>0.05) between with and without astaxanthin supplementation in terms of survival, weight and carapace width. The survival of crablets decreased linearly over the nursing period and final survival of crablets in the Cup method (63.0%) remained three times higher (P<0.05) than the Substrate method (21.3%). The final average survival ranged from 16.7 to 68.5%. Among the water quality parameters, temperature, pH, Nitrite (NO2) and Nitrate (NO3) had negative linear correlations with survival, while dissolved oxygen (DO) had positive linear correlations. Average survival at 30 ppt salinity was 1.67 time higher than at 29 ppt salinity. In conclusion, to increase crablet survival during nursing, maintaining suitable environmental conditions and using Cup method are suitable for preventing cannibalism. Keywords : Cannibalism, Crablet nursing, Cup method, Environmental conditions, Astaxanthin