环境因素对虎纹蛙胚胎发育的影响

The Influence of the Environmental Factors on the Embryonic Development of Rana tigrina rugulosa

就温度、盐度、p H值及水中溶氧四个环境因素对虎纹蛙胚胎发育的影响进行了系统研究。结果表明 :其适宜的孵化水温为 2 0～ 30℃ ,在此温度范围内 ,随着温度的升高 ,胚胎发育速度加快 ,水温在 (30± 1)℃时 ,胚胎发育到鳃盖完成期需 58.8h,孵化率为 84 .2 % ;水温 (2 0± 0 .5)℃时 ,需 2 0 3.9h,孵化率为 89.0 % ;水温 (2 5± 1)℃时 ,需时 84 .0 h,孵化率最高 ,达 94 .5%。盐度对虎纹蛙胚胎发育影响很大 ,盐度越高 ,胚胎畸形率越高 ,且发育经历时间越长 ,孵化水体的盐度应在 1.9以下 ,最适宜用淡水孵化。p H过高或过低都对胚胎发育不利 ,孵化水体的 p H值以 6 .5～ 8.5为宜。虎纹蛙胚胎发育的不同阶段对水中溶氧量要求不同 ,在肌肉效应期、鳃血循环期和鳃盖完成期 ,水中溶氧的半致死浓度分别为0 .57mg/ L、1.13mg/ L和 0 .4 0 mg/ L。

In this paper, the influences of the temperature, salinity, pH value and the dissolved oxygen on the embryonic development of Rana tigrina rugulosa have been studied.The results show that the embryos can normally develop in temperatures ranging from 20℃ to 30℃ and within this range,the velocity of the embryonic development will be accelerated as the temperature rises. To develop to the stage of operculum complete, it needs 58 h and 50 min at (30±1)℃, and the hatch rate is 84.2%; At (20±0.5)℃, it needs 203 h and 55 min, the hatch rate is 89.0%; At (25±1)℃, it needs 83 h and 57 min,it has the tiptop hatch rate:94.5%. The salinity has a great influence on the embryonic development of Rana tigrina rugulosa, the abnormality rate of embryo increases and the time of development will be prolonged as the salinity increases. The salinity suitable for its development is under 1.9‰. However, the fresh water is optimum for hatch.The water of pH 6.5～8.5 is suitable for incubation. At different stage of the development, the embryos requires different dissolved oxygen content in water. The Lc50 of dissolved oxygen at the stage of muscular response, gill circulation and opercular complete is 0.57 mg/L、1.13 mg/L and 0.40 mg/L respectively.