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Ecological niche has close relations with inter-species competition and resources utilization, and thus, can be used as an indicator to symbolize the resources utilization capability of certain groups of related species. In this paper, the niche breadth and overlap of the dominant zoo- plankton species in the Sanmen Bay of Zhejiang were determined by Shannon's formula and Petraitis index, respectively, and the differentiation of the niche was studied by canonical correspondence analysis (CCA), aiming to approach the distribution features of coastal zooplankton and related affecting factors in the Bay. In the study area, some coastal species such as Zonosagitta bedoti, Centropages dorsispinatus, and brachyuran larvae had wider niche breadth than the pelagic species such as Flaccisagitta enflata and Pseudeuphausia sinica, and the species of different groups with prey- predator relation had a greater niche overlap than those of the same groups without this relation. The CCA analysis showed that the spatial distribution of the zooplankton was more affected by water temperature, salinity, and chlorophyll a content rather than nutrients. The spatial niche of the zoo- plankton species was correlated with their living habit, inter-species competition, and prey-predator relationship. [ABSTRACT FROM AUTHOR]

To study the molecular response mechanisms of copepod to nickel stress, a suppression subtractive hybridization (SSH) cDNA library of Pseudodiaptomous annandalei under nickel stress was constructed by using SSH technique, and a total of 140 clones were randomly picked from the growing colonies and identified by PCR. The recombinant rate of the library was 98. 6%, and the volume of the library was 1. 12×106 cfu. After the recombinant plasmids were sequenced, a partial cDNA fragment of ferritin was recognized based on BLAST searches in NCBI, with a size of 859 bp and continuously encoding 170 amino acid residues. The semi-quantitative PCR results showed that the ferritin cDNA under 24 h nickel stress was distinctly up-regulated. The successful construction of the SSH library and the obtaining of ferritin cDNA fragment would supply basis for the further study of the molecular response mechanisms of copepod to nickel stress. [ABSTRACT FROM AUTHOR]