新型鱼用饲料原料紫背浮萍人工养殖的初步研究

The primary study on Spirodela polyrriza as new plant protein sources for fish

为探究紫背浮萍是否可以作为鱼用饲料新型植物蛋白源,本试验在室外采集初始干重为(2.03±0.01)g鲜紫背浮萍,经清洗与饥饿处理后将其随机分为8组(以养殖第1天开始,每隔4 d一个组收割),每组3个平行,按照环境承载量一半的密度放置于表面积为0.5×0.075 cm2的养殖水槽中,在室外自然光照(光暗时间比为16 h∶8 h)下,以养殖水体Hoagland’s E-Medium为营养液,p H为7.8±0.2,水温(26.6±1.1)℃,人工养殖29 d后测定其生长性能、营养物质与天然色素的含量。试验结果表明:人工养殖紫背浮萍29 d后,其干生物量呈"J"型上升趋势,叶绿素含量(叶绿素a:1.78 mg/g,叶绿素b:1.02 mg/g,总叶绿素:2.80 mg/g)显著提高(P<0.05);到养殖第25天时,相对增长率降低至最低,且营养指标达到饱和(粗蛋白质:32.82%,粗脂肪:6.07%),总类胡萝卜素含量(1.10 mg/g)无显著差异(P>0.05)。因此,人工养殖紫背浮萍可应用于水产动物养殖场中,不仅能够处理养殖污水,还能大面积收割作为饲料原料,最终可形成一个生态循环的水产动物养殖模式。

In this study,in order to explore whether Spirodela polyrrhiza can be used as new plant protein sources for fish feed,the fresh Spirodela polyrrhiza with initial dry weight （2.03±0.01）g were collected outdoor, and randomly divided into 8 groups after cleaning and starvation and set 3 parallel each group （Harvest every 4 days each group since the first day to start farming）,then placed in the 0.5 cm×0.075 cm breeding aquarium that aquaculture water were Hoagland5s E - Medium nutrient solution,with the density adjusted to half of environmental carrying capacity, outdoor natural light（The ratio of light time to dark time was 16 h8 h） , pH 7.8±0.2,water temperature （26.6±1.1）℃.The growth performance, nutri- ent and natural pigment content were measured after 29 days.The results showed that the dry biomass of Spirodela polyrrhiza showed a “ J” type upward trend, and the content of chlorophyll was significantly increased after 29 days （chlorophyll a：1.78 mg/ g ,chlorophyll b：1.02 mg/ g , and total chlorophyll 2.80 mg/ g ） （ P〈0.05） ; The relative growth rate decreased to the lowest and the nutritional index reached saturation after 25 days （crude protein：32.82%, crude fat： 6.07%）,and there were no significant difference about total carotenoid content （1.10 mg/ g）（P〉0.05）.Therefore, the Spirodela polyrrhiza can be applied to aquatic animal farms, not only can deal with the aquaculture wastewater, but also can use for feed ingredients,and ultimately can form an ecological cycle of aquatic animal breeding mode.