Study of stress resistance tests on blue swimming crab, Portunus pelagicus larvae

Abstract

Blue swimming crab, Portunus pelagicus is well-known as a source of protein for human worldwide. Stress resistance tests done in conjunction to determine the preferable range of salinity, temperature, pH, ammonia, maximum period of starvation and dissolved oxygen for optimum P. pelagicus larvae survival. .Larvae were exposed to various treatments such as mentioned above to examine larvae competency against the stressor. ln starvation test, at 12 h, more than 50 percent of larvae was observed dead, hence no survival achieved in this treatment. Low survival rate at elevated temperature while at ambient temperature 30°C, highest survival was observed. No survival recorded at O ppt, l O ppt and 50 ppt respectively. The optimum salinity range is 30-34 ppt. Salinity 30 ppt did produce better survival rate compared to the others. pH below 8 did produce low survival rate, as acidic pH significantly influenced the larval survival. Low ammonia level did not provide significant effect that might adversely affect the larvae.