池养美洲鲥亲本强化适应培育及产卵受精规律

Intensive adaptive cultivation, spawning and fertilization laws of Alosa sapidissima broodstock cultured in earthen ponds

于2017年和2018年采用强化培育、水流刺激、水温调控等方法,观察和研究了池塘培育美洲鲥亲本的强化适应培育及产卵受精规律和趋势。结果显示:池塘培育美洲鲥雌雄鱼2龄达到初次性成熟,繁殖期为5-7月份;美洲鲥亲本强化适应培育成活率为69.4%~92.9%,卵巢Ⅴ期的产前雌鱼体长(34.62±2.90)cm、体质量(844.11±134.78)g、肥满度2.07%±0.42%、卵巢质量(232.22±73.42)g、卵巢性腺指数27.59%±6.47%(17.39%~35.20%)、卵巢腔内游离卵的数量和质量分别为(3.226±2.734)万粒和(114.83±73.42)g。2017年和2018年产卵持续时间分别为35 d(5月17日-6月21日)和89 d(5月4日-7月31日),产卵总量分别为277.96万粒和471.48万粒,日均产卵量分别为8.18万粒和5.30万粒,受精卵总量分别为18.58万粒和74.47万粒,平均受精率分别为6.68%和15.80%。美洲鲥产卵(2018年)可分为产卵稳定期(第1、3、4、5和6旬)、产卵高峰期(第2旬)和产卵停滞期(第7~9旬)3个时期,随时间(旬)的推移,日产卵量旬均值总体呈现先上升后下降趋势,受精率旬均值呈现显著的双峰波动趋势,而日受精卵量旬均值呈现微弱的双峰波动;总体上说,日产卵量、日受精卵量及受精率随产卵持续时间(日)均呈现有顶点、开口向下的二次函数抛物线(P<0.01)。研究建议,美洲鲥促产交配适宜水温为16~20℃,促产期间投喂高营养价值的饲料,产卵持续60 d后结束促产调控。

From 2017 to 2018,through intensive adaptive cultivation,water flow stimulation,and water temperature control,the laws of spawning and fertilization of Alosa sapidissima broodstock cultured in earthen ponds were observed and studied.The results showed:The first sexual maturity age of male and female A.sapidissima broodstocks was 2 years,and the breeding season lasted from May to July;The survival rate of intensive adaptive cultivation of A.sapidissima broodstocks was 69.4%-92.9%,prenatal females(ovaryⅤstage):body length was(34.62±2.90)cm,body weight was(844.11±134.78)g,the condition factor was 2.07%±0.42%,the average weight of ovary was(232.22±73.42)g,the ovary gonadosomatic index(GSI)was 27.59%±6.47%(17.39%-35.20%),the quantity and weight of free eggs in ovarian cavity were(32.26±27.34)thousand and(114.83±73.42)g,respectively.In 2017 and 2018,the spawning period of female lasted 35 d(from May 17 to June 21)and 89 d(from May 4 to July 31),spawning egg amount were 2779.6 thousand and 4714.8 thousand,daily spawning egg amount were 81.8 thousand and 53.0 thousand,fertilized egg amount were 185.8 thousand and 744.7 thousand,the average fertility rates were 6.68%and 15.80%,respectively.There were three stages in spawning of A.sapidissima in 2018:spawning steady stage(0-10 day and 30-60 days),spawning peak stage(10-20 days),and spawning stagnation stage(70-90 days).As time(ten-day)goes on,the ten-day average of the daily spawning egg amount presented earlier-increase and later-decrease trend,the ten-day average of fertility rate presented significant bimodal fluctuation trend,and the ten-day average of the daily fertilized egg amount presented weak bimodal fluctuation trend.On the whole,as time(day)goes on,the daily spawning egg amount,the average fertility rate,and the daily fertilized egg amount showed the parabola of the quadratic function with vertices and openings downwards(P<0.01).The suitable water temperature of mating and spawning of A.sapidissima broodstock is 16-20℃;High nutritive value feed is fed during mating and spawning periods;After broodstock laid eggs for 60 days,the spawning regulation ended.