保安湖麦穗鱼种群生物学V.生产力

POPULATION BIOLOGY OF TOPMOUTH GUDGEON IN THE BAOAN LAKE V. PRODUCTION

  • 摘要: 在1995年10月至1996年11月,依据有关种群参数估算了保安湖1#试验围拦中麦穗鱼的生产力.月平均瞬时生长率的变化与年龄和季节有关,随着年龄增加生长率降低,在生活史的早期阶段生长最快,生长率一般在春、夏季较高.在研究期间,种群平均生物量为18.27kg·hm-2,周年生产力为36.53kg·hm-2·a-1,P/B系数为2.0.1996世代对总生产力的贡献为67.9%.种群月平均生物量及生产力均表现出了较明显的季节变化,生物量在秋季(9月)出现峰值,生产力在冬季非常低,在夏季(7月)出现峰值,夏季生产力占总生产力的77.6%.

     

    Abstract: Production by P. parva from the 1# experimental enclosure of the Bao-an Lake, Hubei province, was estimated during the period of from October 1995 to November 1996. Monthly instantaneous growth rate changed with both age and season. Growth in weight decreased with increasing age, being maximal during the early months of life. The growth rate was generally higher in spring and summer. Mean biomass, annual production and P/ B ratio of the population were 18.27kg穐m-2, 36.53kg穐m-2穉-1, and 2.0, respectively. The 1996 year class contributed 67.9% of the total annual production, the 1995 year class, 30.5%, and the 1994 year class only 1.6%. Mean monthly biomass and production of the whole population showed a markedly seasonal variation. Maximum biomass occurred in early autumn(September), while maximum production was observed in mid-summer(July). The summer production(June to August)contributed 77.6% of annual production by the population.

     

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