藻菌生物絮团中光照强度对凡纳滨对虾育苗效果的影响

为探究藻菌生物絮团系统中光照强度对于凡纳滨对虾幼体培育的影响,在实验桶上方分别设置了200 W(L200组)、100 W(L100组)和0 W(L0组)3种光照进行育苗实验,光照强度分别为(8422±195)lx、(4400±204)lx和(3±1)lx。整个养殖过程不换水,养殖14 d。结果显示:藻菌生物絮团系统能较好控制氨氮、亚硝氮等水质指标,增大光照强度能有效降低水体pH与碱度的下降幅度。L200组仔虾体长与体质量显著高于其他组(P<0.05)。高强度的光照提高了幼体存活率,降低了水体总弧菌数占比,但各组差异不显著(P>0.05)。L200组仔虾水分含量显著低于其他组(P<0.05)。光照强度对仔虾粗蛋白质与粗脂肪含量影响不明显。各组絮团营养成分无显著性差异(P>0.05)。实验表明,在藻菌共处型生物絮团系统中,施加一定光照强度可使水质更稳定,促进虾苗生长发育,对育苗生产有益。

Effects of light intensity on the breeding of Litopenaeus vannamei in algal-bacterial-based biofloc system

In order to explore the effects of light intensity on the breeding of Litopenaeus vannamei in algal-bacterial biofloc technology system, three different lighting were designed for experiment, including light of 200W (L200), light of 100W (L100) and light of 0W (L0). The light intensity of three groups is (8 422±195) lx,(4 400±204) lx and (3±1) lx. During the experimental period, larvae were cultured for 14 days in a zero-water exchange system. The results showed that the algal-bacterial-based biofloc system can control the water quality well, and increase of the light intensity can effectively reduce the drop of pH and alkalinity. The body length and weight of larvae in L200 were significantly higher than those in other groups (P<0.05). High intensity light improved the survival rate of larvae and reduced the proportion of total Vibrio in water, but there was no significant difference among 3 each groups (P>0.05). Additionally, the moisture content of larvae in L200 was significantly lower than that in other groups (P<0.05). The effect of light intensity on crude protein and crude fat content was not obvious. Significantly, there was no difference in the nutritional composition of BFT in each group (P>0.05). The results demonstrated that the application of a certain amount of light intensity in the algae-bacteria system was beneficial to water quality control and enhancement of shrimp quality.