Vertical segregation and population structure of ontogenetically migrating copepods Neocalanus cristatus, N. flemingeri, N. plumchrus and Eucalanus bungii during ice-free season in the Sea of Okhotsk
Vertical segregation and population structure of ontogenetically migrating copepods Neocalanus cristatus, N. flemingeri, N. plumchrus and Eucalanus bungii during ice-free season in the Sea of Okhotsk
复制标题
鄂霍次克海无冰季个体发生迁徙桡足类新桡足类、弗氏猪笼草、李子猪笼草和蓝桉的垂直分离和种群结构
DOI：
10.1007/s10872-015-0287-3
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发表时间：
2015
影响因子：
2.3
通讯作者：
J. Nishioka and T. Nakatsuka
中科院分区：
文献类型：
--
作者：
Tsuda;A. H. Saito;H. Kasai;J. Nishioka and T. Nakatsuka
The Sea of Okhotsk is a semi-enclosed marginal sea of the subarctic North Pacific. One of the prominent characteristics of this area is the fast ice coverage during winter and early spring. We investigated the life cycles and vertical distributions of four species of large suspension feeding copepods,Neocalanus plumchrus, N. flemingeri, N. cristatus, andEucalanus bungiiin the southern part of the Sea of Okhotsk during the ice-free season.Neocalanus plumchrusandN. cristatusshowed annual life cycles while a major part of the population ofN. flemingeriandE. bungiishowed biennial life cycles. Their occurrences in the surface layer for grazing and development were 1–2 months later than in the adjacent area of the Pacific Ocean, and they remained longer in the surface layer for development. Consequently, the seasonal overlap among the copepods in the surface productive layer was intensified. In contrast, the vertical distribution of the four species of copepods during the growing period extended to deeper layers and became more finely segregated than those of Oyashio region and open ocean of the North Pacific. Thus, the seasonal segregations in the Oyashio region are replaced by vertical segregation in the Sea of Okhotsk. A major factor modifying the seasonal occurrences in the surface layer was considered to be the presence of fast ice during winter and early spring which greatly reduces the photosynthesis in the water column.
