体重、年龄和应激刺激对菲牛蛭繁殖性能的影响

采用单因素方差分析等方法探讨人工养殖条件下体重、年龄和环境应激对菲牛蛭繁殖性能的影响。结果表明,体重对卵茧大小和湿质量及幼蛭体长、体宽和湿体质量无显著影响(P>0.05),而亲蛭性腺系数、平均产茧数、孵化率和平均孵化数在各组间差异显著(P<0.05),其中体重10～15g组明显高于其他组(P<0.05);年龄对亲蛭平均产茧数、孵化率、平均孵化数和卵茧大小影响显著(P<0.05),其中2～3年龄亲本具有最高的平均产茧数、孵化率和平均孵化数,8月龄亲本所产卵茧个体明显大于其他年龄组(P<0.05),而卵茧湿质量及幼蛭体长、体宽和湿体质量在各年龄组间均无显著差异(P>0.05)。环境应激对亲蛭的平均产茧数、孵化率和平均孵化数影响显著(P<0.01),其中1～2次操作应激下的平均产茧数和孵化数最高,无操作刺激下的孵化率略高于1～2次操作刺激(P>0.05),而卵茧大小和湿质量及幼蛭体长、体宽和湿体质量在各应激处理组间无显著差异(P>0.05)。本研究获得了菲牛蛭繁殖的最佳体重和年龄,建议繁育生产中挑选10～15g和2～3年龄的个体作为亲本,期间进行1～2次操作刺激可提高其繁殖性能。

Effects of Broodstock Body Weight, Age and Stress on the Reproductive Performance of Hirudinaria manillensis

The effects of broodstock body weight, age and environmental stress on the fecundity of the Hirudinaria manillensis under experimental conditions was evaluated using single factor analysis of variance as well as other methods. The results showed that the broodstock body weight cannot influence the cocoon size and wet weight, or the body length, body width and wet weight of juvenile significantly (P>0.05). Gonadal somatic index of parent leech, mean number of cocoons produced, hatching rate and mean hatching number of cocoon under different broodstock body weights were significantly different (P<0.05), and among the three groups, the broodstock body weight of 10~15 g were higher than other groups (P<0.05). Broodstock age significantly affected the mean number of cocoons produced, hatching rate and mean hatching number of cocoon, and cocoon size (P<0.05). The mean number of cocoons produced, hatching rate and mean hatching number of cocoon were the highest under the broodstock age of 2~3 years. The cocoon size of 8 months parent leech was obviously greater than others (P<0.05). The cocoon wet weight, body length, body width and wet weight of juvenile were not significantly different among the four broodstock age groups (P>0.05). Environmental stress had a significant impact on the mean number of cocoons produced, hatching rate and mean hatching number of cocoon (P<0.01). Among the four groups, the mean number of cocoons produced and hatching number of cocoon under the stress of 1~2 times were the highest, and the hatching rate of cocoon under control group was higher than others, yet which between stress groups of 0 and 1~2 times present no difference (P>0.05). The cocoon size and wet weight, and the body length, body width and wet weight of juvenile were not significantly different among the four environmental stress groups (P>0.05). In conclusion, the investigation has obtained the optimal broodstock body weight and age, and suggests that the body weight of 10~15 g and age of 2~3 years could be used to select the parent leeches for the breeding industry of this species, during the course of which, environmental stress of 1~2 times might improve the reproductive efficiency of parent leeches.