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Cephalomonas ( Cp .) granulata N. L. Higinb. (Volvocales, Chlorophyceae), a rare volvocalean phytoflagellate, has recently been isolated from a paddy field in Japan and examined by light and fluorescence microscopy. The vegetative cells of Cp . granulata have granulate loricae and a characteristic mushroom-like shape with a hemispherical to spherical anterior part and narrower posterior part. Cp . granulata has been classified among the Phacotaceae along with other loricated genera. However, its phylogenetic position has not been investigated using molecular phylogeny. To evaluate the phylogenetic position of Cephalomonas , the 18S r RNA gene sequence of the Japanese strain was determined. The phylogenetic analyses revealed that Cp . granulata was not closely related to other loricated taxa with known phylogenetic affinities, such as Phacotaceae sensu stricto ( Phacotus , Pteromonas , and Wislouchiella ) and Dysmorphococcus globosus . This indicates at least three independent origins of loricae within the Volvocales.  相似文献   

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Two new species and one new variety of Salix L. from western China, namcl. S. ludingensis T. Y. Ding et C. F. Fang, S. neoamnematchinensis T. Y. Ding et C. F. Fang, and S. taoensis Gorz var. leiocarpa T. Y. Ding et C. F.Fang, are reported in this paper.  相似文献   

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Two new species of the genus Sanicula (Umbelliferae), S. pengshuiensis Sheh etZ.Y.Liu and S. oviformis X.T.Liu et Z.Y.Liu, are described from Sichuan Province, China.  相似文献   

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我国东北地区发现姬鼩鼱分布   总被引:1,自引:0,他引:1  
2014年在黑龙江省横道河子地区(44°48′44″N,129°02′04″E,海拔约740 m)采集到1只鼩鼱(标本编号为CH5)。2015年在内蒙古自治区达赉湖地区(48°37′20″N,117°53′17″E,海拔约720 m)采集2只鼩鼱(标本编号为DE7和DE12)。这些新获标本经鉴定为姬鼩鼱(Sorex minutissimus)。《小鼩鼱(食虫目:鼩鼱科)辽宁省新纪录》文中的标本(080910,090920)经重新鉴定也为姬鼩鼱。利用mt DNA的Cyt b基因全序列构建系统进化树,结果揭示,小鼩鼱聚为一支,姬鼩鼱聚为另一支,新获标本(CH5、DE7、DE12)和待厘定标本(080910、090920)都聚在姬鼩鼱一支,进一步支持形态学鉴定结果。2015年采集的姬鼩鼱为内蒙古自治区新纪录,而《小鼩鼱(食虫目:鼩鼱科)辽宁省新纪录》文中的小鼩鼱(Sorex minutus)(标本号:080910,090920)更正为辽宁省姬鼩鼱新纪录。  相似文献   

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本新种与黄山花楸(Sorbus amabilis Cheng ex Yü)近缘,区别在于前者羽状小叶6~7对,边缘圆钝锯齿,托叶宽披针形,花部雄蕊20枚,10长,10短,复伞房果序排列紧密,果多达160~195粒。  相似文献   

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Smilax austro-zhejiangensis Q. Lin (Liliaceae) is described as new fromZhejiang Province, China.  相似文献   

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One new species of the genus Spiradiclis (Rubiaceae), S. longibracteata S. Y. Liu et S. J. Wei from Guangxi Autonomous Region is described in this paper.  相似文献   

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We studied interrelationships between initial egg size and biomass, duration of embryogenesis at different salinities, and initial larval biomass in an estuarine crab, Chasmagnathus granulata. Ovigerous females were maintained at three different salinities (15‰, 20‰ and 32‰); initial egg size (mean diameter), biomass (dry weight, carbon and nitrogen) as well as changes in egg size, embryonic development duration, and initial larval biomass were measured.

Initial egg size varied significantly among broods from different females maintained under identical environmental conditions. Eggs from females maintained at 15‰ had on average higher biomass and larger diameter. We hypothesise that this is a plastic response to salinity, which may have an adaptive value, i.e. it may increase the survivorship during postembryonic development. The degree of change in egg diameter during the embryonic development depended on salinity: eggs in a late developmental stage were at 15‰ significantly larger and had smaller increment than those incubated at higher salinities. Development duration was longer at 15‰, but this was significant only for the intermediate embryonic stages. Initial larval biomass depended on initial egg size and on biomass loss during embryogenesis. Larvae with high initial biomass originated either from those eggs that had, already from egg laying, a high initial biomass (reflecting individual variability under identical conditions), or from those developing at a high salinity (32‰), where embryonic biomass losses were generally minimum. Our results show that both individual variability in the provisioning of eggs with yolk and the salinity prevailing during the embryonic development are important factors causing variability in the initial larval biomass of C. granulata, and thus, in early larval survival and growth.  相似文献   


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