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
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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