Enhancement of survival and metamorphosis rates of Penaeus monodon larvae by feeding with the diatom Thalassiosira weissflogii

The purpose of this study was to compare the performance of two species of diatoms, Thalassiosira weissflogii and Chaetoceros gracilis, in the larviculture of the black tiger shrimp Penaeus monodon. Shrimp larvae were fed with either C. gracilis, T. weissflogii, or a combination of the two species of diatoms. The larvae fed solely with T. weissflogii or a combination of the two types of diatom had significantly higher survival rates and faster metamorphosis than those fed solely with C. gracilis. The numbers of diatom cells consumed by larvae during 3-h periods were determined, revealing that larvae consumed significantly higher numbers of C. gracilis than T. weissflogii. However, when the protein, total fatty acid, and polyunsaturated fatty acid content of the two species of diatom are compared, significantly higher amounts of each are found in T. weissflogii. Converting the number of diatom cells consumed into equivalent protein, total fatty acid, eicosopentaenoic acid, and decosahexaenoic acid reveals that larvae fed with T. weissflogii received significantly higher amounts of all the nutrients, compared to those consuming C. gracilis. The results showed an advantage of feeding T. weissflogii to C. gracilis in enhancing survival and metamorphosis in P. monodon larvae.