不同转食策略对花斑副沙鳅仔鱼和稚鱼生长及存活率的影响

The effect of different food conversion strategies on the growth and survival rate of larvaeand juveniles of Parabotia fasciata

为研究不同转食策略对花斑副沙鳅(Parabotia fasciata)仔鱼和稚鱼生长及存活率的影响,探寻其最佳转食策略,设置5个转食起始点,分别为孵化出膜后第7天(W7组)、第9天(W9组)、第11天(W11组)、第13天(W13组)和第15天(W15)组,设计5个转食过渡时间,分别为2 d(W9-1组)、4 d(W9-2组)、6 d(W9-3组)、8 d(W9-4组)和10 d(W9-5组)。结果表明,孵化出膜23 d时,W13组试验鱼存活率最高,为83.33%,明显高于其余各组;孵化出膜11~15 d、15~19 d时,各组试验鱼特定生长率无显著差异(P>0.05),孵化出膜19~23 d时,W13组试验鱼特定生长率显著小于其余各组(P<0.05);W15组试验鱼体长和体重明显高于其余各组。W9-5组试验鱼存活率明显高于其余各组,孵化出膜25 d时,W9-5组试验鱼存活率为89.30%;孵化出膜21~25 d时,W9-1、W9-2组试验鱼特定生长率明显高于其余各组(P<0.05);W9-5组试验鱼体长和体重最大,其次是W9-4组,其余各组试验鱼体长和体重都随转食过度时间的缩短而降低。综合分析,推荐花斑副沙鳅仔鱼和稚鱼在孵化出膜13 d时开始转食,且以8 d作为转食的最佳过渡时间。

To investigate the effects of different food conversion strategies on the growth and survival rate of larvae and juveniles of Parabotia fasciata,and to explore the optimal food conversion strategy,5 starting points for food conversion were set,namely the 7th day(W7 group),9th day(W9 group),11th day(W11 group),13th day(W13 group),and 15th day(W15)groups after hatching out of the membrane,and 5 transition times for food conversion were designed,namely 2 days(W9-1 group),4 days(W9-2 group),6 days(W9-3 group),8 days(W9-4 group),and 10 days(W9-5 group).The results showed that after hatching out of the mem-brane for 23 days,the W13 group had the highest survival rate of 83.33%,which was significantly higher than the other groups;after hatching out of the membrane for 11-15 days and 15~19 days,there was no significant difference in the specific growth rate of experi-mental fish among the groups(P>0.05).However,after hatching out of the membrane for 19~23 days,the specific growth rate of ex-perimental fish in the W13 group was significantly lower than that in the other groups(P<0.05);the body length and weight of fish in the W15 group were significantly higher than those in the other groups.The survival rate of experimental fish in the W9-5 group was significantly higher than that in the other groups.After hatching for 25 days,the survival rate of experimental fish in the W9-5 group was 89.30%;after hatching out of the membrane for 21~25 days,the specific growth rate of experimental fish in the W9-1 and W9-2 groups was significantly higher than that in the other groups(P<0.05);the W9-5 group had the largest body length and weight,fol-lowed by the W9-4 group.The body length and weight of the other experimental groups decreased with the shortening of the transition time.Based on comprehensive analysis,it was recommended that the food conversing of larvae and juveniles of Parabotia fasciata start-ed after hatching out of the membrane for 13 days,with 8 days as the optimal transition time for feeding.