Abstract: Using central composite design (CCD) and response surface methodology, the combined effects of temperature (24-32 ℃) and salinity (25-35) on hatchability and average hatching time of fertilized eggs from Sepia pharaonic were evaluated on the basis of singlefactor tests. The results showed that the linear and quadratic effects of temperature and salinity and their interactive effects significantly affected hatchability and average hatching time (P<0.05). The hatchability increased first and then decreased as temperature or salinity increased. The average hatching time decreased as temperature increased, while it increased after an initial increase as salinity increased. The model equation of hatchability and average hatching time towards temperature and salinity were established, with the coefficients of determination (R²) being 0.9791 and 0.9774, respectively. The optimized results of regression equation based on a reliability of 0.985 showed that the hatchability was 88.11% when temperature was 27.6 ℃ and salinity was 31.1, and the average hatching time was 21.8 d when temperature was 26.2 ℃ and salinity was 29.6. Our results suggest that the hatching of fertilized eggs of S. pharaonis can be improved by rearing with an optimal combination of temperature and salinity with the range of 26-28 ℃ and 29-31, respectively.

Key words: functional connectivity, least cost path, circuit theory, pinch point, ecological corridor