The influence of light on Penaeus vannamei and Penaeus monodon larval production and acclimation to temperature and salinity of postlarval Penaeus vannamei and Penaeus monodon

Research was conducted to determine the influence of light spectra, intensity, and photoperiod on the final weight, survival, and rate of metamorphosis of larval Penaeus vannamei and P. monodon. Light spectra included red, blue, green, and white. Light intensities were 0.6, 3.4, and 6.8 uE/m^2/sec. Photoperiods used were 24L:0D, 12:12, and 0:24. No significant influence was found on final postlarval weight, survival, or rate of metamorphosis in any of the light spectra treatments. There were no significant differences noted between P. vannamei and P. monodon. The postlarval dry weight was significantly lower in the intermediate 12:12 photoperiod as compared to the other two. Postlarvae aged 1, 5, 10, and 20 days old were challenged at salinities of 0, 5, 10, 15, 20, and the ambient salinity of 30 ppt, and at temperatures of 24, 28, and 32°C. There was increasing tolerance to salinity challenges with increasing age. P. vannamei postlarvae had well developed acclimation capabilities at P10, while in P. monodon, this was delayed until P20. There were significant differences between the two species. There was a significant reduction in survival at extreme salinity challenges in both species when coupled with thermal stress at 32°C There was no increase in tolerance to salinity challenge either due to previous acclimation to reduced salinity of 20 ppt, or based on prior acclimation at 24°C.