Population biomass, feeding, respiration and growth rates, and carbon budget of the scyphomedusa Aurelia aurita in the Inland Sea of Japan
Population biomass, feeding, respiration and growth rates, and carbon budget of the scyphomedusa Aurelia aurita in the Inland Sea of Japan
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DOI：
10.1093/plankt/fbh172
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发表时间：
2005-03
影响因子：
2.1
通讯作者：
S. Uye;H. Shimauchi
中科院分区：
文献类型：
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作者：
S. Uye;H. Shimauchi
本文调查了日本内海中部地区金鱼的季节发生、湿：干：碳/氮重量比、种群生物量、胃袋内容物、摄食率、生长速率和呼吸速率。水母水母在1/2月开始以肺泡的形式出现，在7/8月份达到年度最大体型，到11月消失，推测是由于死亡。在潮汐混合强烈的内海海峡，浮游动物群落生物量(平均碳生物量：66.0mgCm�3)在5~8月上旬占绝对优势(微型和中浮游动物平均生物量：23.7mgCm�3)。胃容物分析表明，Aurita摄食几乎所有的微型和中游浮游动物，其中小的桡足类是最重要的。根据野外采集的小骨足类消化时间(60min)及其在胃袋中的丰度，测定了其体重比摄食率和排泄率。前者随着桡足类丰度的增加而线性增加，但后者相对恒定，与食物供应无关。我们还测量了金龟子的呼吸速率，并将其表示为体重和温度的函数。这些生理生态参数使我们能够构建翁多海峡典型的初夏极光种群的碳收支。预测的种群摄食率(6.07mgCm�3d�1)高于新陈代谢和生长所需的种群食物需要量(4.55mgCm�3d�1)，表明食物供应足以维持观察到的增长率。这一摄食率相当于微型和中型浮游动物生物量的26%，对浮游动物的影响很大。
We investigated the seasonal occurrence, wet : dry : carbon : nitrogen weight ratios, population biomass, gastric pouch contents, and rates of feeding, growth and respiration of the scyphomedusa Aurelia aurita in the central part of the Inland Sea of Japan. Aurelia aurita medusae began to appear in January/ February as ephyrae, reached annual maximum body size in July/August, and disappeared, presumably due to death, by November. Initial slow growth in early spring was followed by a period of exponentialgrowth(meangrowthrate:0.069d � 1 )betweenAprilandJuly.IntheOndoStrait,whichis characterized by strong tidal mixing, the A. aurita population (mean carbon biomass: 66.0 mg C m � 3 ) overwhelmingly dominated the zooplankton-community biomass (mean biomass of micro- and mesozooplankton: 23.7 mg C m � 3 ) between May and early August The gastric content analysis revealed that A. aurita ate almost all micro- and mesozooplankters, of which small copepods were most important. On the basis of digestion time for small copepods (60 min) and their abundance in the gastric pouch of field-collected A. aurita, we determined the weight specific feeding rates and clearance rates. The former increases linearly with increasing copepod abundance, but the latter was relatively constant irrespective of the food supply. We also measured the respiration rates of A. aurita and expressed them as functions of body weight and temperature. These physio-ecological parameters enabled us to construct the carbon budget of the A. aurita population typical of early summer in the Ondo Strait. Predicted population-feeding rate (6.07 mg C m � 3 d � 1 ) was higher than the population-food requirement for both metabolism and growth (4.55 mg C m � 3 d � 1 ), indicating that food supply was sufficient to sustain the observed growth rate. This feeding rate was equivalent to 26% of microand mesozooplankton biomass, a significant impact on zooplankton.