| 摘要: |
| 为了解自然环境中中华哲水蚤的摄食选择性及其生态策略,利用库尔特颗粒计数器测定了夏季黄海中华哲水蚤对自然水体中混合饵料的选择性摄食状况。调查期间,黄海海域季节性温跃层开始出现,水体中叶绿素a浓度为0.23-1.44mg/m3,最大值均出现在温跃层底部。水平分布上,水体中颗粒浓度近岸浅水区(A站:0.5-5.2×106 μm3/ml)高于深水区(B站:0.3-0.7×106 μm3/ml,C站:0.9-2.4×106 μm3/ml);垂直分布上A、B站近底层颗粒浓度最高,C站颗粒浓度最高值出现在叶绿素a最大值区。中华哲水蚤对水体中粒径为1-100 μm的食物颗粒均有摄食,但是颗粒大小和颗粒浓度对其摄食选择性均有一定的影响,主要摄食粒径为5-50 μm的饵料颗粒。不同海域中华哲水蚤的个体摄食率分别为近岸A站23.82×106 μm3/d、北部B站51.16×106 μm3/d和南部C站36.32×106 μm3/d,其日摄食量分别占体碳含量的2.1%(A站)、4.6%(B站)和3.2%(C站)。近岸海域(A站)中华哲水蚤摄食的饵料颗粒中各粒级组所占比例变化不大,但是深水区(B、C站)中华哲水蚤对于10-25 μm范围内的饵料颗粒摄食选择性明显高于其它粒级组。中华哲水蚤的摄食选择性主要与水体中饵料的体积浓度相关，当饵料浓度降低时，中华哲水蚤可以通过扩大摄食饵料颗粒的粒径范围，增加对大颗粒的摄食以获得更多的营养。 |
| 关键词: 中华哲水蚤 摄食选择性 黄海 |
| DOI： |
| 分类号: |
| 基金项目:中国科学院知识创新工程重要方向项目,KZCX2-YW-213号;国家自然科学青年基金资助项目,40106016号 |
附件 |
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| AN EXPERIMENTAL STUDY ON GRAZING SELECTIVITY OF CALANUS SINICUS TO NATURAL FOOD PARTICLES |
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LI Chao-Lun, SUN Song, WANG Rong
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Key Laboratory of Marine Ecology and Environmental Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071
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| Abstract: |
| An investigation on grazing selectivity of Calanus sinicus, the ecological strategy in a natural environment, and in situ selective grazing on natural food particles was performed in the Yellow Sea in summer (July) 2002 with the aid of Coulter Counter. During the period, a seasonal thermocline existed, the chlorophyll-a concentration ranged 0.23 - 1.44 mg/m3, and the maximum value occurred at the bottom of the thermocline. The horizontal distribution of particle concentration in shore (Station A: (0.5 - 5.2)×106 μm3/ml) was higher than those in deep-water areas (Station B: (0.3 - 0.7)×106 μm3/ml; Station C: (0.9 - 2.4)×106 μm3/ml), while in vertical direction, in Stations A and B, the maximum particle concentration occurred in the bottom, whereas the maximum co-occurred in the maximum chlorophyll-a layer. C. sinicus was able to consume particles between 1 and 100 μm, mostly between 5 and 50 μm. Both particle size and concentration influenced the grazing selectivity of the copepod. The individual ingestion rate was 23.82×106 in Station A (nearshore), 51.16×106 in Station B (the northern area), and 36.32×106 in Station C (the southern area) in unit of μm3 per day, taking 2.1%, 4.6% and 3.2% of body carbon per day, respectively. No obvious difference in proportion of different size groups to the total particles taken by C. sinicus at station A, while at deeper stations B and C, however, the grazing was greater on particles in size between 20 and 25 μm. The grazing selectivity was strongly related to the volume concentration of food particles. If food concentration decreases, C. sinicus would be able to extend its food size spectrum, increasing its grazing pressure on the large particles to obtain more nutrition. |
| Key words: Calanus sinicus, Grazing selectivity, The Yellow Sea |
