Embryo development indices for the endangered Chinese sturgeon, Acipenser sinensis: the role of temperature on incubation time

The impact of global warming on the initial growth and development of fish, including sturgeons, is evident. The embryonic development phase is crucial for the preservation and propagation of the Chinese sturgeon, yet the specific influence of water temperature on this process remains inadequately documented. This study conducted experiments using three temperature groups (16, 19, and 22 ℃) to investigate the impact of temperature on the embryonic development of Chinese sturgeon. Subsequently, five statistical models were utilized to fit the developmental data through regression analysis, in order to determine the correlation between incubation time and temperature of the embryos. Data from cultured Chinese sturgeon embryos were finally utilized to validate water temperature development indices. Over the temperature range of 16–22 ℃, water temperature was positively related to the rate of embryonic development in Chinese sturgeon. The time to hatching in the group experiencing the highest temperature (22 ℃) was nearly cut in half in comparison to the group exposed to the lowest temperature (16 ℃). Among the five regression models, the S (sigmoidal) model was the best for predicting the incubation period of Chinese sturgeon embryos from temperature (R² = 0.939, p < 0.01). Based on the progression from incubation to initial hatching, we estimated daily development indices, ranging from 10.66 to 32.22% between 14 and 25.9 ℃. The water temperature development indices of Chinese sturgeon established in this study have the potential to improve the accuracy of predicting hatch timing and the transfer of fish fry, thereby aiding in the conservation and enhancement of Chinese sturgeon resources.