Quality determination of pacific white shrimp (Litopenaeus vannamei) postlarvae using salinity shock, thermal hock, and formaldehyde dipping

Abstract

The methods of determination for Pacific white shrimp (Litopenaeus vannamei) postlarvae/PL quality were not well recognized by the user or the PLs producer. The objectives of these trials were to determine the correlation of salinity shock, thermal shock, and formaldehyde (37%) dipping (dose and duration) to the survival rate/SR of PLs 10. The thermal shock was conducted at 9, 12, 15, and 18 oC. Salinity shock was conducted with 0, 5, 10, and 15 ppt. Formaldehyde dipping was accomplished with 300, 600, 900, and 1.200 ppm. The survival rate (SR) of tested PLs was observed every 15 minutes for 60 minutes. The results showed that PLs demonstrated 100% survival in all salinity test levels but 0 ppt, which caused a decrease in SR after 30 minutes and longer exposures. The lowest threshold for temperature stress was 15 oC with 90% SR. The PLs demonstrated 90% of SR at below 600 ppm of formaldehyde stress test at all exposure durations. The findings of this study provide basic information for shrimp farmers regarding the threshold level for salinity, temperature, and formaldehyde stress during aquaculture handlings.