Real-time imaging and developmental biochemistry analysis during embryogenesis of Caridina pseudogracilirostris

This paper reports on the real-time imaging and developmental biochemistry of the freshwater caridean shrimp, Caridina pseudogracilirostris. The complete time-lapse development of a single embryo was recorded in an artificial mold, developed in our lab, and imaged under a stereomicroscope. It took 8 days to complete the 5 stages of embryonic development (1 cleavage stage, 2 gastrulation stage, 3 nauplius stage, 4 prehatching embryo, and 5 zoea stages). As the decapod eggs are enriched with dense yolk, biochemical determination of the major components was made to evaluate the yolk utilization during embryogenesis. The concentration of protein, lipid, and carbohydrate declined drastically from Stage I (cleavage) to Stage IV (Zoea), reflecting sustained yolk utilization during embryogenesis. The increase in the size of the embryo correlates with changes in water content. Lipids, being the principal organic substrate, changes in the fatty acid (FA) composition of embryos during development were determined by GC. The FA composition was observed within the range of 25%-60.87% for saturated, 22.57%-56.45% for monounsaturated, and 5.64%-18.51% for total polyunsaturated FAs. The essential polyunsaturated fatty acid were higher in Stages I, IV, and V, suggesting a major role in embryogenesis. The cellular proliferation and organogenesis as visualized in the real-time imaging correlate well with the biochemical variations observed in C. pseudogracilirostris.