无锡市河埒口高产鱼池水质的研究——Ⅱ.浮游生物

STUDIES ON THE WATER QUALITY OF THE HIGHYIELD FISHPONDS IN HE LIE COMMUNE, WUXI SHI II. PLANKTON

无锡河埒口高产鱼池的浮游植物量多在20—100毫克/升之间,以隐藻门为代表的鞭毛藻类占很大优势,绿球藻类和硅藻类次之,蓝藻极少。浮游动物量平均大约为浮游植物量的1/4—1/3,以轮虫为主。 当地养鱼池的水色,主要由膝口藻、隐藻、裸甲藻和绿球藻的水华颜色决定的。膝口藻水华是渔民最欢迎的“肥水”,隐藻水华和绿球藻类水华为一般“肥水”,裸甲藻水华被称为“转水“。 文中对“肥、活、嫩、爽”的生物学内容同浮游生物量及鲢、鳙鱼产量的关系进行了分析。

This paper embodies the results of observations on the plankton in eight fish pondsin Heliekou, Wuxi shi and three fish ponds in Wuli hu fish farm during the growingseason in 1977. Samples were collected at 5-7 days intervals from four main pondsand at semi-month intervals from seven ordinary ponds.The biomass of phytoplankton determined by the method of calculating cell volumegenerally varies between 20--100mg/L, in which the flagellate algae were predomina-ted and Cyanophyte was rare.The average biomass of zooplankton is about the 1/4 to 1/3 that of phytoplankton.Rotifers are dominate.The fish farmers judge the quality of water by observing of water colour. Thecolour of the fertile water is mainly caused by the water blooming of four dominateplanktons: Gonyostomum bloom. Cryptomonas bloom, Gymnodinium bloom andChlorococus bloom. According to the experinence of the fish-farmer. the brown greenwater which caused by Gonyostomum bloom is the best fertile water, the brown watercaused by Cryptomonas bloom and the Green water caused by Chlorococus bloom arethe medium fertile water, while the socalled changing water which caused by the Gym-nodinium bloom is an informediat form which either may change to be good water ormay change to be bad water.Based on a rough caculation the production of the silver and bighead carp about60--90% comes from the plankton energy in the different times.