Starch gel electrophoresis was used to analyze genetic structure of three populations of Oxya chinensis from Shanxi Province,China.Four allozyme polymorphic loci (MDH-1,MDH-2,LDH,ME) were found.The data suggest that t...Starch gel electrophoresis was used to analyze genetic structure of three populations of Oxya chinensis from Shanxi Province,China.Four allozyme polymorphic loci (MDH-1,MDH-2,LDH,ME) were found.The data suggest that two populations of O.chinensis about 41 kilometers apart are genetically similar,but differentiated from the third population with a geographic distance of 357 kilometers.However,the heterozygosity levels of those two genetically similar populations were much different.The Nei's genetic distance between two geographically close populations is 0.068,which is much smaller than those of geographically distant populations (0.23 in average).The observed overlap of geographical distance and genetic distance implies that for O.chinensis population divergence may correlate with geographic isolation.展开更多
The Yellow Sea Cold Water Mass （YSCWM） was suggested as an over-summering site of the dominant copepod species Calanus sinicus in coastal Chinese seas. Population abundance and structure were investigated by monthly...The Yellow Sea Cold Water Mass （YSCWM） was suggested as an over-summering site of the dominant copepod species Calanus sinicus in coastal Chinese seas. Population abundance and structure were investigated by monthly sampling along three transects across the northern boundary of the YSCWM during 2009-2010. Results show that thermal stratification existed from June to October and that the vertical thermal difference increased with depth. Generally, total abundance was lowest in October and highest in June, and the female/male sex ratio was highest in February and lowest in August. Evident spatial differences in abundance were observed during the existence of the YSCWM. In June, total abundance averaged 158.8 ind/m~ at well-stratified stations, and 532.1 ind/m3 at other stations. Similarly, high abundances of 322.0 and 324.4 ind/m3 were recorded from July to August inside the YSCWM, while the abundance decreased from 50.4 to 1.9 ind/m3 outside the water mass. C. sinicus distribution tended to even out over the study area in September when the YSCWM disappeared. We believe that the YSCWM may retard population recruitment in spring and preserve abundant cohorts in summer. The summer population was transported to neritic waters in autumn. In addition to low temperatures, stable vertical structure was also an essential condition for preservation of the summer population. C. sinicus can survive the summer in marginal areas in high abundance, but the population structure is completely different in terms of C5 proportion and sex ratio.展开更多
文摘Starch gel electrophoresis was used to analyze genetic structure of three populations of Oxya chinensis from Shanxi Province,China.Four allozyme polymorphic loci (MDH-1,MDH-2,LDH,ME) were found.The data suggest that two populations of O.chinensis about 41 kilometers apart are genetically similar,but differentiated from the third population with a geographic distance of 357 kilometers.However,the heterozygosity levels of those two genetically similar populations were much different.The Nei's genetic distance between two geographically close populations is 0.068,which is much smaller than those of geographically distant populations (0.23 in average).The observed overlap of geographical distance and genetic distance implies that for O.chinensis population divergence may correlate with geographic isolation.
基金Supported by the Knowledge Innovation Program of Chinese Academy of Sciencesthe National Basic Research Program of China(973 Program)(No.2011CB403604)the IOCAS-Zhangzidao Fishery Eco-Mariculture Joint Laboratory
文摘The Yellow Sea Cold Water Mass （YSCWM） was suggested as an over-summering site of the dominant copepod species Calanus sinicus in coastal Chinese seas. Population abundance and structure were investigated by monthly sampling along three transects across the northern boundary of the YSCWM during 2009-2010. Results show that thermal stratification existed from June to October and that the vertical thermal difference increased with depth. Generally, total abundance was lowest in October and highest in June, and the female/male sex ratio was highest in February and lowest in August. Evident spatial differences in abundance were observed during the existence of the YSCWM. In June, total abundance averaged 158.8 ind/m~ at well-stratified stations, and 532.1 ind/m3 at other stations. Similarly, high abundances of 322.0 and 324.4 ind/m3 were recorded from July to August inside the YSCWM, while the abundance decreased from 50.4 to 1.9 ind/m3 outside the water mass. C. sinicus distribution tended to even out over the study area in September when the YSCWM disappeared. We believe that the YSCWM may retard population recruitment in spring and preserve abundant cohorts in summer. The summer population was transported to neritic waters in autumn. In addition to low temperatures, stable vertical structure was also an essential condition for preservation of the summer population. C. sinicus can survive the summer in marginal areas in high abundance, but the population structure is completely different in terms of C5 proportion and sex ratio.
