Morphological peculiarities of Calanus finmarchicus and Calanus glacialis in the areas of the co-existence of their populations

Morphological studies of the females of Calanus finmarchicus, C. glacialis, and C. hyperboreus were performed for specimens sampled in different areas of the Greenland, Barents, Kara, and Laptev seas. Intraspecific variability was found for the ratio of the specimens characterized by different types of setae patterns on the endopodites of C. glacialis and C. finmarchicus. The variability of this parameter did not relate to the environmental peculiarities of the sampling sites and did not depend on the temperature regime. We assume that such differences may be the result of the hybridization of C. glacialis and C. finmarchicus due to the similarity of their reproduction systems and the overlapping of the body size ranges.     

Feeding selectivity of Calanus finmarchicus in the Trondheimsfjord

The feeding selectivity of Calanus finmarchicus was studied by carrying out three incubation experiments; two experiments with natural seawater sampled during spring bloom (Exp. 1) and post-bloom conditions (Exp. 2) and a third experiment with cultured dinoflagellates and ciliates (Exp. 3). In the first two experiments a gradient in ciliate concentration was created to investigate the potential for prey density dependent selective feeding of C. finmarchicus. Results of microplankton counts indicated C. finmarchicus to be omnivorous. Diatoms contributed chiefly to the diet during spring bloom conditions. Despite the high microphytoplankton biomass during the spring bloom (Exp. 1), ciliates were selected positively by C. finmarchicus when the ciliate biomass exceeded 6.5 μg C L^− 1. A selection in favor of large conic ciliates such as Laboea sp. and Strombidium conicum was indicated by positive selectivity indices. Ciliates were throughout positively selected by C. finmarchicus during Exp. 2, and selectivity indices indicated a negative selection of diatoms. The results from Exp. 3 showed that C. finmarchicus has the ability to switch from dinoflagellates to ciliates as sole food source, even if the dinoflagellate was offered in surplus. This suggests that other factors, such as nutrition may be of significance for the feeding selectivity of C. finmarchicus.     

温度对中华哲水蚤代谢率的影响

海洋生态系统的能流和物流是海洋生态学研究的重要内容。中华哲水蚤 (Ｃａｌａｎｕｓｓｉｎｉｃｕｓ)是中国黄、渤海桡足类的优势种 ,本文研究了中华哲水蚤的代谢率 ,为研究海洋生态系统的能流和物流积累资料。１材料和方法１９９７年１２月２６日到１９９８年１月１７日在中科院海洋研究所研究了温度对中华哲水蚤耗氧率和排氨率的影响。１９９７年６月渤海调查时 ,在“科学１号”调查船上研究了温度对中华哲水蚤耗氧率的影响。中华哲水蚤１９９７年１２月２６日到１９９８年１月１７日实验用中华哲水蚤采自青岛汇泉湾 ,用浅水 Ｉ型网在中…     

中华哲水蚤生态学研究进展

浮游动物在海洋生态系统中起着至关重要的作用 ,而真正起控制作用的往往只是少数的优势种。中华哲水蚤 (Ｃａｌａｎｕｓｓｉｎｉｃｕｓ)是我国近海及日本沿岸海的浮游动物优势种之一 ,它与北挪威沿岸海及巴伦支海大西洋区域的浮游动物优势种———飞马哲水蚤 (Ｃ．ｆｉｎ ｍａｒｃｈｉｃｕｓ)的角色相同 ,分布广、数量多、个体大 ,因此在探讨我国海洋浮游动物种群动力学中该种受到广泛的关注。在国际ＧＬＯＢＥＣ研究计划中 ,将飞马哲水蚤作为生态系统中浮游动物的关键种进行深入研究 ,我国近海海洋生态系统动力学也已将中华哲水蚤列为关键…     

厦门港中华哲水蚤碳氮收支的研究

本文在分析厦门港中华哲水蚤元素组成基础上,研究其各项生理速率并估算碳氮收支.结果表明:摄食率与饵料含量呈线性相关,未发现饱和摄食.同化效率介于92％～96％之间,与饵料含量及摄食率无关.呼吸率与摄食率及同化率均呈线性相关,其SDA系数介于摄入碳量的9.3％(m/m)或同化碳量的9.9％(m/m).总氮排泄率随摄食率与同化率的提高而呈线性增加.随着摄食率的提高,分配给卵生产的能量也增多,二者呈线性相关.饵料中N含量是厦门港中华哲水蚤生长的主要限制因子,当其对N的摄食率低于10.5×10~(-3)(m/m)/d时,动物“负”生长.     

中华哲水蚤不同地理种群苹果酸脱氢酶(MDH)的比较

中华哲水蚤 (ＣａｌａｎｕｓｓｉｎｉｃｕｓＢｒｏｄｓｋｙ)是属于甲壳纲 (Ｃｒｕｓｔａｃｅａ)桡足亚纲 (Ｃｏｐｏｐｅｄａ)哲水蚤目（Ｃａｌａｎｏｉｄａ）哲水蚤属（ＣａｌａｎｕｓＬｅａｃｈ）的一类浮游动物 ,为暖温带种 ,广泛分布于我国渤、黄海和东海沿岸区 ,为这些水域的优势种［１］。有关中华哲水蚤的研究国内有过许多报道 :李少菁［２］、陈清潮［３］、林元烧等［４］曾分别对该种类生活习性、摄食、生殖及生活史进行过研究 ,林元烧、曹文清等［５］也曾对厦门港不同月份采集的中华哲水蚤染色体组型进行了分析。而不同地理种群…