Abstract：The cuttlefish Sepia pharaonis, an important fishery species in tropical archipelagic environments is highly required in both local and international market trades. Therefore, intensive efforts are currently undertaken to develop practical effects of fundamental physical and chemical parameters on the hatching rate of S. pharaonis fertilized eggs. In this report, the effects of three environmental factors that including temperature, salinity, and pH value were investigated, to understand the suitable ecological conditions for S. pharaonis hatching and enhancement of stocks to provide necessary data for the artificial breeding of S. pharaonis. The present study was conducted following a factorial design to evaluate the appropriate breeding parameters of cuttlefish at different temperatures(18, 21, 24, 27, 30 and 33 ℃), various salinity at(15‰, 18‰, 21‰, 24‰, 27‰, 30‰, 33‰ and 36‰) and at altered pH ranges(7.0, 7.5, 8.0 and 8.5). Results indicate that different temperatures had significant effects(P<0.05) towards hatching of fertilized eggs at 21-30 ℃. With the increase of temperature, the incubation period was significantly shortened, and the optimal temperature was 27 ℃ with the hatching rate of 72.2%. The salinity has a significant effect on the hatching rate of S. pharaonis fertilized eggs at 27‰-36‰, and the optimum salinity ranged from 30‰-33 ‰ with the hatching rate of 70%-80%. By contrast, the effect of pH value on the hatching rate of S. pharaonis was not significant(P>0.05), and the hatching rate was all greater than 70% under the pH values of 7.0-8.5. Regardless of pH, the temperature and salinity are critical factors affecting the hatchability performance of S. pharaonis fertilized eggs. Collectively, the present findings suggest that the artificially hatching conditions for the fertilized egg of S. pharaonis could be set as 24-27 ℃, 30‰-33‰ and pH value at 7.0-8.5 and these patterns may prove helpful in the maintenance of hatchery conditions for aquaculture purposes.
2019, Vol. 32 
