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机构地区:[1]大连水产学院养殖系
出 处:《大连水产学院学报》1990年第3期7-17,共11页Journal of Dalian Fisheries University
摘 要:根据1986年4月至1987年6月,在金州渔场进行的采集研究,摇蚊科幼虫的年消长状况是两个高峰期(5~7月;2~3月)两个低峰期(8~10月;4~5月)。通过逻辑斯帝方程的计算,金州渔场204池摇蚊幼虫种群自然内禀增长率r为0.027;最大持续产量Msy为7.16(个/d);最大持续产量的种群水平NMsy为530(个/d);104池的r值为0.1135;Msy为252(个/d),NMsy为4442(个/d)。针对204池细长摇蚊的跟踪采集,并应用Allen所建方程计算得单位面积的真正净产量为141233(mg/m^2);P/B系数为2497。Midge larvals from fishing ponds were studied from Apr, 1986 to Jun 1987. Using the methods of collecting specimens with modified Peterson grab and the emergence traps, about two handreds sampling were carried out for the last two years. Specimens were extracted and identified. The data collected are used to show the annual fluctuations in the number of individuals in cohort md its biomass, to describe the population growth by the logistic equation, to determine the intrinsic rate of increase of the population, to estimate the various components of production for the population of larval of Chironomus attenuatus from Mar to Jun, 1987, in which the actual net production is 1412.33 g/m2 and to give the r'tio as 2.497 of the total production (P) of C.attenuatus to its biomass (B). It does support notice that the presence of fish predators are main reason for a pond's bcnthic decrease in abundance for the period Mny-Jun, 1987.
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