Effect of temperature, salinity, and body length on the energy budget of Daphniopsis tibetana Sars (Cladocera: Daphniidae)

We investigated the effects of temperature (14, 20, and 22°C), salinity (5, 10, 15, 20, and 25), and body length (0.83, 1.17, 1.49, and 2.33 mm) on the energy budget of Daphniopsis tibetana Sars in the laboratory. The results demonstrated no difference in D. tibetana assimilation efficiency (AE) with values of 51.59%–56.22% at the trial temperatures. Gross growth efficiency ( K1 ) and net growth efficiency ( K2 ) were 28.78% and 55.71%, respectively, at 14°C. Daphniopsis tibetana energy conversion efficiency (AE, K1, and K2) was higher at salinities of 10–20, with values of 72.80%–77.31%, 42.50%–50.42%, and 58.43%–65.02%, respectively. Daphniopsis tibetana energy conversion efficiency was highest when body length was 1.17–1.19 mm, with values of 83.70%–84.73%, 50.11%–50.81%, and 59.13%–60.71%, respectively. The results of this study can provide a reference for large-scale cultivation use of D. tibetana in the further.