Abstract:

Taiwan loach is an excellent breeding species, and the mechanism of salinity on its hatching rate and emergence rate during artificial breeding is not clear. In order to clarify the optimal salinity for hatching and emergence of Taiwan loach, and to screen the optimal salinity range suitable for hatching of Taiwan loach fertilized eggs and emergence of larvae, it provides technical support for large-scale seedling breeding in Anyue area. The fertilized eggs of Taiwan loach were used as experimental materials, and different salt addition gradients of 0‰, 2‰, 4‰, 6‰, 8‰ and 10‰ were set to carry out artificial hatching experiments. The water temperature was controlled at 21℃ and pH 8.0. Three parallels were set in each group to determine the hatching rate and emergence rate under different salinity conditions. The results showed that salinity had a significant effect on the hatching rate and emergence rate of Taiwan loach, showing the rule of ‘low promotion and high inhibition’. When the salinity was in the range of 0‰ - 2‰, the hatching rate and emergence rate reached the highest level, and the hatching rate of 2‰ salinity group was 50‰, which was significantly higher than that of other treatment groups. The emergence rate of the salinity group reached 46%, which was also the highest in each treatment group. When the salinity exceeded 2‰, the hatching rate and emergence rate continued to decrease with the increase of salinity, and the emergence rate decreased to 0 when the salinity was ≥ 8‰. The suitable salinity range for the hatching of Taiwan loach fertilized eggs and the emergence of larvae is 0‰ - 2‰. This salinity condition can effectively improve the efficiency of seedling breeding and provide guidance or reference for the hatching and emergence of Taiwan loach.

Key words: Taiwan loach, salt content, hatchability, emergence rate