Effects of complex probiotics on fatty acid composition of gonad,fecundity and survival rate of larvae in koi carp Cyprinus carpio
SHI Dongjie1, HU Jinyou2,LI Wentong1, JIANG Jufeng3, ZHU Hua1*,WANG Saisai1,CHEN Xiaoxuan4,ZHANG Xin1
1.National Engineering Research Center for Freshwater Fisheries, Beijing Fisheries Research Institute, Beijing 100068, China; 2.China Agricultural University, Beijing 100083, China; 3.Tianjin Ornamental Fish Technology and Engineering Centre, Tianjin Fisheries Research Institute, Tianjin 300221, China; 4.College of Fisheries, Tianjin Agricultural University, Tianjin 300380, China
Abstract: Broodstocks of 3 years old red and white koi carp Cyprinuscarpio with body weight of [female fish (2649.0±257.5)g, male fish (2349.0±283.9)g] were reared in a 3.2 m × 1.8 m ×1.5 m circulating aquaculture pond and fed basic diet (group E, control group) and the basic diets containing Bacillussubtilis, Clostridiumbutyricum, and Enterococcusfaecalis at proportions of 1∶1∶1 (group A), 1∶1∶5 (group B), 2∶3∶3 (group C), and 4∶2∶3 (group D)at water temperature of (24±2)℃ for 90 d to probe for the effects of complex probiotics on fatty acid composition of the gonad, fecundity and larvae survival rate. The results showed that there were higher amounts of unsaturated fatty acids, monounsaturated fatty acids, polyunsaturated fatty acids, C18:1n-9, C18:2n-6 and C18: 3n-3 in the female fish fed the diets containing the complex probiotics than those in the fish fed the control diet, the maximal values in group B, significantly higher content of total polyunsaturated fatty acids, EPA and DHA in group B than those in the control group (P<0.05). The female fish fed the diets containing the complex probiotics had higher gondal-somatic index, absolute fecundity, and relative fecundity in body weight than the female fish fed the control diet did, significant differences only between the group B and the control group (P<0.05), and without significant difference in gonadal-somatic index among groups (P>0.05). There were higher fecundity, fertilization rate, hatching rate, and survival rate of larvae in the spawners fed the diets containing probiotics than those in the control group, the indices above being significantly higher in group B than those in the control group(P<0.05). The findings indicated that the compound probiotic diet significantly promoted the gonadal development of koi carp, the reproductive performance of females and the survival rate of larvae, with the optimal ratio of 1∶1∶5=Bacillussubtilis∶Clostridiumbutyrate∶Enterococcusfaecalis.
2020, Vol. 35 
