长江上游宜宾至丰都江段漂流性鱼卵的静水沉降特性  

Hydrostatic Settling Characteristics of Drifting Fish Eggs in MainStream of Yangtze River from Yibin to Fengdu

作　　者：张先炳 张堪瑞 杨威[1] 王丽 杨胜发[1] 李文杰[1] 张鹏[1] ZHANG Xian-bing;ZHANG Kan-rui;YANG Wei;WANG Li;YANG Sheng-fa;LI Wen-jie;ZHANG Peng(Chongqing Jiaotong University,National Inland Waterway Regulation Engineering Technology Research Center,Chongqing Key Laboratory of Ecological Waterway,Chongqing 400074,China)

机构地区：[1]重庆交通大学,国家内河航道整治工程技术研究中心,重庆市生态航道重点实验室,重庆400074

出　　处：《长江流域资源与环境》2022年第9期1918-1925,共8页Resources and Environment in the Yangtze Basin

基　　金：国家自然科学基金项目(42007213);国家内河航道整治工程技术研究中心暨水利水运工程教育部重点实验室开放基金项目(SLK2015B06)。

摘　　要：漂流性鱼卵的孵化是随水迁移时同步进行的,其孵化率与鱼卵在水体中的运动特性密切相关。为研究长江上游漂流性鱼卵在静水中的沉降特性,于2021年6月16日至7月8日在长江干流宜宾至丰都江段设置了5个漂流性鱼卵采样点,共采集鱼卵848粒,对其中随机挑选的399粒鱼卵进行了静水沉降特性研究。结果表明:(1)漂流性鱼卵的粒径为4.0~8.0 mm,其中粒径为5.0~7.0 mm的鱼卵占到捕获总量的88%。(2)漂流性鱼卵密度为1.0012~1.0034 g/cm^(3),其中密度为1.0022~1.0032g/cm3的鱼卵占捕获鱼卵总量的78.9%。(3)漂流性鱼卵的静水沉降速度为3.0~12.0 mm/s,平均静水自由沉速为7.16 mm/s。影响漂流性鱼卵自由沉速的主要原因是:鱼卵在静水沉降过程中会带动水体产生局部的微小紊动、胚胎在膜内的无规则自主运动、卵膜受到水体挤压而产生形变以及鱼卵密度的变化。通过鱼卵在静水中的受力分析、并结合粒子的静水沉降方程和试验数据,拟合得出长江上游宜宾至丰都江段漂流性鱼卵静水沉降与绕流阻力相关系数k=0.609。The incubation of drifting fish eggs is synchronized with their migration in water,and the success of the incubation also closely related to the fish eggs’movement behavior in water.To study the settling characteristics of drifting fish eggs in static water,five sampling sites were chosen for drifting fish eggs collection in the Yibin-Fengdu river steam of the Yangtze River main stream from June 16 to July 18,2021.A total of 848 drifting fish eggs were collected and 399 of them were randomly selected for their hydrostatic settling studied.The results show that:(1)the diameter of the drifting fish eggs is 4.0-8.0 mm,and 88%of the fish eggs’diameter is 5.0-7.0 mm.(2)The density of the drifting eggs is 1.0012-1.0034 g/cm3,and 78.9%of the fish eggs’density is 1.0022-1.0032 g/cm3.(3)The terminal settling velocity of those drifting eggs is 3.0-12.0 mm/s(with average velocity was 7.16 mm/s).The following reasons are the main factors that affect the terminal settling velocity of the drifting fish eggs:movement of fish eggs in static water will lead to slight water turbulence behind the eggs,irregular autonomous movement of fish egg embryo,fish egg membrane deformation and changes in density due to compression by water.The hydrostatic settling coefficient(k=0.609),which is related to disturbance resistance,was obtained by combining the hydrostatic settling equation and experimental data with the force analysis of drifting fish eggs in static water in the upper Yibin-Fengdu river stream of the Yangtze River.

关 键 词：漂流性鱼卵 粒径 密度 自由沉速 长江上游 

分 类 号：S932.4[农业科学—渔业资源]