摘要
研究池养鲢、鳙鱼的食物组成,消化利用和摄食强度。结果表明:鲢、鱅鱼食物种类多数相同,但鲢滤食小型浮游生物较多,鳙滤食大型浮游生物较多。鲢食物中浮游植物与浮游动物的数量比为552:1,是鳙的3.6倍;生物量比值为1.17:1,是鳙的7.3倍。故鲢以浮游植物为主要食物,鳙以浮游动物为主要食物;但宜通称为食浮游生物的鱼类。鲢、鳙对硅藻、金藻、隐藻、裸藻中大部分种类消化良好,对甲藻、蓝藻和绿藻中部分种类可以消化,大部分难以消化。鲢、鳙摄食强度具明显昼夜节律性变化。摄食低谷在清晨2—6时,高峰在14时左右。摄食强度随溶氧、水温升降和食物丰歉波动。
The natural food contents of silver carp and bighead, containing hoth phytoplankton and zooplankton, are rather similar, but the former takes more minute species than that of the latter. The ratio of the number of individuals of phytoplankton to that of zooplankton in silver carp is 552:1, while it is 153: 1 in bighead, The silver carp, then, takes 2,6 times more phytoplankton than bighead expressed in number of food organisms, As for the biomass of food items, the ratio are culculated 1.17:1 in silver carp and 0,16:1 in bighead respectively, and then the former takes 6.3 times more phytoplankton by weight than the latter. Conclusively, these two species are exactly planktotrophic fish, or planktonophage, but the silver carp feed mainly on phytoplankton while bighead mainly on zoophytoplankton. Algae of phyla Bacillariophyta, Chrysophyta,Cryptophyta, pyrrophyta and Euglenophta are well digested by these two fishes. Digested and undigested individuals of Oscillaloria (Cyanophyta), Cosmarium, Scenedesmus and Pediustrum (Chlorophyta) were both obserued in the intestine. Other members of Cyanophyta, such as Merispodium and Chroococcous, and Dectyloccofsis, Coccomyxa and Chlorogomium of Chlorophyta are species of bardly to incorporate in digestion. It is considered that the degress of digestibility of the above montioned species is in a great extent associated with the chemical and physical conditions of the water and oonditions of the fish itself. The diurnal feeding rhythm of the two fishes is almost the same, the highest index of saturation was observed in 2 p. M., the lowest in 6 A. M. .
出处
《华中农业大学学报》
CAS
CSCD
北大核心
1989年第4期385-394,共10页
Journal of Huazhong Agricultural University
关键词
鲢鱼
yong鱼
摄食习性
池养鱼
Silver carp [Hypophthalmichthy molitrix(C, et V.)]
bighead [Aristichthys nobilis(Richardson)] : food contents, degress of digestibility of algae
feeding rhythm.
