繁殖时间、体质量及催产剂量对华鳈人工繁殖的影响

The Effects of Time,Size and Dose of Oxytocinon the Artificial Reproduction of Sarcocheilichthyssinensis

采用组织学的方法观察繁殖季节华鳈卵巢的组织结构,比较4、5月份华鳈的性腺发育及人工繁殖情况,另将雌性华鳈分成分别注射促黄体素释放激素(LRH-A2)+地欧酮(DOM)的高剂量和低剂量催产素后进行人工繁殖.结果发现,华鳈为分批产卵鱼类,在繁殖季节卵巢中同时存在处于各个时相的卵母细胞,分步成熟,连续补充.4月份发育到V期卵巢的华鳈占比为66.67%,高于5月份的38.46%,且成熟系数也高于5月份.因此,4月份华鳈人工繁殖的孵化率显著高于5月份(P<0.05).高剂量催产剂能显著提高不同体质量雌性华鳈的催产率,但受精率则不受亲本体质量和催产剂量的影响而出现显著变化.高剂量催产剂显著降低了已成熟的高体质量华鳈的孵化率,但低剂量催产剂则可显著提高正成熟的体质量小的华鳈的孵化率.总之,能否确定出华鳈最佳的繁殖时间对其人工繁殖的成败至关重要.

Using histological method the ovarian structure of Sarcocheilichthys sinensis was observed and the gonad development and the artificial reproduction of Sarcocheilichthys sinensis between April and May were compared. In addition, the female parents were divided into two groups which had the in- jection of high or low dose of LRH - A2 -1- DOM separately, then the artificial reproduction was made. This experiment found that Sarcocheilichthys sinensis was partial spawning fish. There would be differ- ent time phase of oocytes during the breeding season. They will mature step by step and supplement con- tinuously. The rate of Sarcocheilichthys sinensis with V matured ovary in April was 66.67% which was higher than those in May with 38.46 %. The maturation coefficients of Sarcocheilichthys sinensis in A- pril were also higher than those in May which led the rate of hatchability was significantly decreased （ P 〈0.05）. High dose of oxytocin could significantly improve the spawning rate of different body weight of Sarcocheilichthys sinensis. However, the rate of fertilization was not significantly affected by the size of fish and dose of oxytocin. High dose of oxytocin could significantly decrease the hatchability of big size of Sarcocheilichthys sinensis. However, low dose of oxytocin could significantly increase the hatchability of small size of Sarcocheilichthys sinensis. In a word, the appropriate time was crucial to the success of artificial reproduction of Sarcocheilichthys sinensis.