中文摘要：

中华哲水蚤是中国近海生态系统浮游动物关键种之一。它是莱州湾内唯一成体大于2mm的桡足类优势种,是仔鱼向幼鱼转换过程中重要的饵料来源。本研究基于2011年5月至2012年4月（除12月和翌年1—2月为冰期外）逐月采集的浮游动物样品,进行了莱州湾中华哲水蚤种群中桡足幼体和成体的生态分布分析。结果表明：在所有调查月份中,中华哲水蚤桡足幼体CI—CV和成体都出现了。桡足期个体的总丰度和生物量季节变化呈单峰型,高峰期出现在5—6月。月均生物量为2.91mg C/m3,丰度为7ind/m3;日生产力和年生产力估算值分别为0.74mg C/（m3·d）和266mg C/（m3·a）。各调查月份中,CIV和CV对总丰度的贡献比例最高;4月和10月以早期桡足幼体CI—CIII居多,8—9月和11月以成体占绝对优势;其他月以后期桡足幼体（CIV和CV）丰度值相对较高。成体中,雌体较多;雌/雄性比值介于0.86—6.46,在11月最高,10月最低。各发育期的前体长月均值在8—9月最低,4月最高;其季节变化与水温呈负相关。丰度分布由莱州湾湾口东侧向湾内逐渐减少;丰度高值区（〉100ind/m3）集中出现于5—6月的表层水温介于15—25℃、盐度高于31—32的站位。

英文摘要：

To understand the population structure,spatial distribution and production contribution of Calanus sinicus Brodsky in Laizhou Bay,Bohai Sea,we analyzed the annual data based on the plankton samples collected in 9 cruises from May 2011 to April 2012（excluding December 2011 and January and February 2012 due to sea ice presence） in the bay.The results show that C.sinicus occurred continuously throughout the year,and peaked in May and June.The biomass and daily production showed a clear seasonal variation in parallel with that of the numerical abundance.The monthly mean biomass was 2.91 mg C/m3,that of abundance was 72ind/m3,and daily production was 0.74 mg C/（m3·d）.The annual production was estimated for 266 mg C/（m3·a）.The stage-specific abundance and body size of the population fluctuated greatly during the study period.Copepodites in stages CIV and CV accounted for the largest proportion of the total population abundance,while those in stages CI—CIII were more abundant in April and October.Adults were dominant in August and September,while in the other surveyed months those of CIV—CV were the major contributors to total abundance.Adult females dominated over males.The female/male ratio ranged 0.86—6.46,down in October and up in November.The body size（prosome length） changed seasonally,large in April and small in August-September.Water temperature was a strong negative factor on the body size.In general,the abundance of C.sinicus decreased southwestward from the mouth.The high abundance（100ind/m3） occurred in May and June in the stations where surface water temperature ranged of 15—25℃,and the salinity was above 31—32.