利用Bootstrap统计方法探讨体长-体重关系中的幂指数对小黄鱼产卵期的指示作用

Testing of power b in exponent relationship between body-length and weight of small yellow croaker as spawning indicator by Bootstrap method

中文关键词: 体长  体重  幂指数  小黄鱼  产卵期  Bootstrap统计方法

英文关键词: Body-length  Weight  Power exponent  Small yellow croaker  Spawning period  Bootstrap

中文摘要:

      利用2004年在29°N以北、127°E以西海域所采集的小黄鱼近全年的生物学数据，在日、周、半月、月4个不同时间尺度下，对小黄鱼体长与体重关系中幂指数的周年变化特征进行了分析。利用Bootstrap统计方法，把小黄鱼产卵期内的幂指数与年内其他时期的进行比较。研究结果显示，全年当中，小黄鱼在产卵期内的幂指数显著偏小(P<0.05)。研究发现，根据平均b值来判断产卵期与非产卵期，采用周、或者比周更长的时间尺度所得到的数据是比较可信的；根据单个采样b值判断，采用半月、或比半月更长的尺度所得到的结果才可信。对全年各时期的幂指数进行分析发现，在4~5月份之间，幂指数出现一个低谷；在11~12月之间，出现一个高峰。且随着时间尺度的提高，这一变化特征更加显著。

英文摘要:

      Based on the biological measurement data of small yellow croakers collected in the sea area in the north of 29°N and the east of 127°E in 2004,the trend of annual change of power b was analyzed by Bootstrap method at four different temporal scales including day,week,half-month，and month.The bootstrap analysis showed that the values of power b during the spawning period were significantly smaller than those of the other periods in the same year (P<0.05).When the average b value from the samples was used for the determination of the periods of spawning and non-spawning,only the results based on the time scales of week or longer were reliable.However,when the b value of a single sample was used for the determination,the results based on the time scales of only half month or longer were reliable.The trend of annual change of power b,with low values during April~May and a peak during November~December,became more obvious with the increase of temporal scales.