单胞藻培养中敌害生物的防治

单胞藻是鱼、虾、蟹幼体的基础饵料,是贝类幼体的优良开口饵料。在单胞藻的大量生产中经常会由于敌害生物的污染和危害,造成生产不稳定,不能保证育苗生产中活饵料的持续供应,从而影响经济苗种的产量。笔者通过几年的实践,总结出几点经验,仅供参考。 1 保种期间 1.1 藻种必须“纯”:大部分生产单位的藻种是由一些科研单位购入,为确保“纯种”,应该再次进行藻种分离。

Effects of Different Live Food Extracts on Fish Attraction Activities

[Objective] This study was to determine the effect of green biological feeds that little affected natural environment on fish attraction activities with the aim to explore new research direction for the recreational fishing area. [Method] The ef- fective constituents of live natural foods, including chironomid larvae, earthworm, mussels, winkles, were separated by using soaking solution extraction and centrifu- gal extraction. The extracted live foods were used to attract the carp, young cru- cian, and fishes of 100-150 days old and over 1 year old, respectively. The feed nutrition formulation of the added food attractants was designed and applied to feed- ing in the aquaculture farm. The test results were practised in bait study to conduct field fishing test and collect the data. [Results] Compared with the control group, feeding with live foods had significantly improved the growth rates of fishes at dif- ferent ages, and greatly reduced food coefficients. [Conclusion] The feeds made from live food addictives had excellent attraction ability, which not only reduced the negative effects on natural environment but also made the aquaculture mode more organic and greener.

摇蚊幼虫提取液和田螺提取液对150日龄鲤鱼的诱食效果研究

以150左右日龄的鲤鱼作为试验对象,通过咬球试验和喂养增重试验,对池塘中生物量大、易于获得的摇蚊幼虫和田螺对鲤鱼的诱食效果进行研究,并对摇蚊幼虫提取液和田螺提取液的常规营养成分和18种氨基酸含量成分进行检测。结果表明,摇蚊幼虫提取液的干物质大于田螺的干物质含量;摇蚊幼虫提取液的粗蛋白含量高于田螺提取液粗蛋白含量;摇蚊幼虫提取液的氨基酸含量总量高于田螺提取液氨基酸含量总量2倍多。摇蚊幼虫提取液和田螺提取液对150左右日龄鲤鱼都有一定的诱食作用,可以诱使鲤鱼提高开口率、增加摄食量,且摇蚊幼虫提取液的诱食效果最为明显。