大口黑鲈选育群体幼鱼转食配合饲料的驯食研究

Transfer Food from Zooplankton to Formulated Feed in Juvenile Selectively Bred Largemouth Bass Micropterus salmoides

将选育的大口黑鲈“优鲈3号”、“优鲈1号”和非选育群体幼鱼各15000尾饲养在3个网箱中,初始平均体质量分别为(0.105±0.020)、(0.106±0.017)g和(0.102±0.012)g,进行幼鱼转食配合饲料的驯化。第1 d投喂自池塘中捕捞的枝角类和桡足类,第2 d和第3 d将浮游动物与粉末状配合饲料按质量比5∶1和1∶1搅拌均匀后投喂,第4 d将浮游动物、粉末状配合饲料及直径0.8 mm的颗粒状饲料按质量比1∶2∶1混匀后投喂,第5 d和第6 d投喂颗粒状饲料,饱食投喂。试验结果显示,驯食结束后,“优鲈3号”、“优鲈1号”和非选育群体的体质量分别增长了83.82%、77.16%和61.30%,体长增长率分别为30.73%、31.03%和20.85%;选育群体显著高于非选育群体(P<0.05)。“优鲈3号”和“优鲈1号”的驯食成功率分别为96.67%和92.67%,显著高于非选育群体(74.0%)。“优鲈3号”、“优鲈1号”和非选育群体的养殖成活率分别为88.6%、81.4%和64.2%,三者间差异显著(P<0.05)。研究结果表明,“优鲈3号”幼鱼的驯食性状优于“优鲈1号”和非选育群体。

Selectively bred juvenile largemouth bass(Micropterus salmoides)Youlu No.3[with initial body weight(0.105±0.020)g],No.1[with initial body weight(0.106±0.017)g]and non-selectively bred larvae[with initial body weight(0.102±0.012)g]were reared in three cages at stocking density of 15000 individuals and fed to satiation as the following:zooplankton including cladoceras and copepods collected from ponds on the first day;zooplankton and powdered formulated feed at the ratio of 5∶1 and 1∶1 on the second and third days;the ratios of zooplankton,powder formulated feed and 0.8 mm diameter formulated feed at the ratio of 1∶2∶1 on the 4th day and 0.8 mm formulated feed on the 5th and 6th days.The results showed that the final body weight was found to be increased by 83.82%in Youlu No.3,77.16%in Youlu No.1 and 61.30%in non-selective larvae at the end of domestication,and the body length to be increased by 30.73%in Youlu No.3,31.03%in Youlu No.1 and 20.85%in non-selective largemouth bass,significantly higher in Youlu No.3 and Youlu No.1 than those in non-bred larvae.The success rate of weaning was 96.67%in Youlu No.3 and 92.67%in Youlu No.1,significantly higher than that in non-selective larvae(74.00%),with survival rate of 88.6%in Youlu No.3,81.4%in Youlu No.1 and 64.2%in non-selective population,significant difference among the groups(P<0.05).The findings indicate that Youlu No.3 largemouth bass is easier to be domesticated to feed complete formula feed than Youlu No.1 and non-selective population,showing the remarkable genetic improvement on the domestication traits in Youlu No.3 largemouth bass.