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ABSTRACT:   In normally fertilized progeny of the kokanee salmon Oncorhynchus nerka , DNA content flow cytometry revealed that all the externally normal embryos were diploid, whereas abnormal embryos exhibited haplo-diploid, diplo-tetraploid and haplo-diplo-tetraploid mosaicisms, together with a few haploid and diploid individuals. When gynogenetic development was artificially induced by fertilization of eggs obtained from a female of the same kokanee brood stock with UV-irradiated sperm, haplo-diploid mosaics appeared most frequently. These mosaics were likely to happen by certain cytological events, such as meiotic or mitotic errors during the process of maturation, fertilization or early cleavage.  相似文献   
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The Bohai Sea is a typical shallow sea in which the average depth of water is about 18 m, and which has a rich biodiversity and abundance of marine life. The values of primary production differ among the four different regions of the Bohai Sea. A biological model consisting of nutrients, phytoplankton, zooplankton and detritus is used to simulate the annual cycles of plankton and primary production in these four regions. The simulation is forced by monthly observational data. Water transparency, nutrient concentrations, temperature and incident irradiance influence the amount and variation of plankton and primary production. The model simulations indicate that transparency and nutrient concentration are the principal causes of the differences in primary production among the four regions of the Bohai Sea.  相似文献   
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