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1.
中国水螅属一新种(水螅虫纲:螅形目)   总被引:7,自引:0,他引:7  
描述采自黑龙江省大庆、泰来和阿城地区的水螅属一新种:大庆水Hydra daqingensis FAn,sp。nov.。新种的主要鉴别特征是:构刺丝囊内顶基部具有4.5~5.0圈横向弹簧状缠卷刺丝,较大型的构刺丝囊、粘刺丝囊和卷刺丝囊,生殖期,雄必个体形成数目较多的精巢(12~18个)和雌性个全产生较多的卵(4~10枚)的遗传特性。标本保存在哈尔滨师范大学生物学系无脊椎动物教研室。  相似文献   

2.
大乳头水螅在中国的首次发现   总被引:2,自引:1,他引:1  
淡水水螅有效物种已记述36种。史新柏等(1987)对哈尔滨的强壮水螅Hydra robustaIto,1947作过报道;范学铭报道了中国水螅4个新种,即哈尔滨水螅Hydra harbinensisFan、漠河水螅Hydra mohensisFan,1999、大庆水螅Hydra daqin-gensisFan,2000和北京水螅Hydra beijingensisFan,2003,  相似文献   

3.
五种水螅基因组DNA的RAPD多态性研究   总被引:2,自引:1,他引:1  
利用RAPD技术对水螅科2属5种水螅进行了基因组DNA多态性研究.80个随机引物筛选出18个引物,共扩增出303个清晰稳定的DNA片段,分子量在0.3~3.0kb之间.以UPGMA聚类法构建树状图,阐明水螅属种的分类关系:大庆水螅Hydra daqingensis、北京水螅H.beijingensis和强壮水螅H.robusta 3种分成两组并聚在一起;不同属的漠河水螅H.mohensis和绿水螅Chlorohydra sp.聚为一支;由此2属5种水螅分为两个支系.  相似文献   

4.
本文报道福建沿海类4新种,既六辐拟线水母Nemopsis hexacanalis sp.nov.,福建无垂水母Orthopyxis fujianensis sp nov.、短柄和平水母Eirene brevistylus.nov.、乳突多管水母Aequorea papillata sp.mov.。  相似文献   

5.
中国水螅属一新种(螅形目,水螅科)   总被引:2,自引:2,他引:0  
记述采自北京地区水螅属1新种:北京水螅Hydra beijingensis sp.nov.。新种的主要鉴别特征是出现体部与柄的分化;钩刺丝囊内刺丝缠绕具有2种形态:大部分钩刺丝囊(占2/3左右)内顶端基部刺丝呈4~5圈横向弹簧状缠绕,而占所观察刺丝囊总数1/3左右的囊内刺丝为不规则缠绕和纵向缠绕。标本保存在哈尔滨师范大学生命与环境科学学院生物学系无脊椎动物研究室。  相似文献   

6.
水螅的反口孔结构和功能   总被引:10,自引:0,他引:10  
汪安泰 《动物学报》1996,42(2):135-139
在230个水螅(Pelmatohydrapseudoligactis)中观察到38例反口孔排物过程。反口孔静止时,基盘附着层外表中心见不到孔迹。反口孔开启时,有废物或气体从孔内排出。连续切片检查,发现反口孔排物前,基盘腔内堆积有食泡残骸等许多废物,孔周死亡细胞和断裂废弃的中胶层在反口孔开启时脱落。非排物期,基盘附着层中心处缺少中胶层。根据观察结果,对反口孔的结构特点及其生理功能作了讨论。  相似文献   

7.
中国水螅属一新种(水螅纲,水螅科)   总被引:1,自引:0,他引:1  
报道采自广东省肇庆市的淡水水螅1新种,多形水螅Hydra polymorphus sp.nov.,研究标本均来自1只水螅的单系繁殖群体,测量数据经生物统计学处理。新种的钩刺丝囊外形及内部刺丝盘旋均有多种形态,故新种名以此命名。所有研究标本保存于深圳大学生命科学学院。  相似文献   

8.
水螅和涡虫的立体生态养殖   总被引:2,自引:1,他引:2  
水螅(Hydra)和三角头涡虫(Dugesia)是动物学实验与研究的重要材料,但由于河流污染和生态环境的破坏,野外已不易采到。人们曾摸索了许多单纯饲养水螅和涡虫的方法,但由于投饵和经常换水等问题,工作量较大而不能长期养殖。我们在研究野外水螅和涡虫共同栖息的小生境的基础上,结合前人的一些经验,于1994年开始在室内进行了水螅和涡虫的立体生态混养实验,获得了成功。1 饲养缸的制作和安放用0.5cm厚的普通玻璃制作长55cm、宽33cm、高25cm和长35cm、宽35cm、高15cm的玻璃缸各1个,前…  相似文献   

9.
水螅(Hydravulgaris)是一种淡水腔肠动物,有原始的两胚层结构:外胚层、内胚层和非细胞结构的中胶层,并出现了组织分化,具有简单的网状神经系统。它是研究动物进化发育的常用材料。自1982年Tatemoto等首次在猪脑中分离得到36个氨基酸的多...  相似文献   

10.
水螅变形虫     
娄柏丹  孙国娜  史新柏 《生物学通报》2007,42(11):21-22,F0004
简述了水螅变形虫的发现和研究历史,报告了在哈尔滨近郊采到的此虫的生境、形态、运动特征及寄生于水螅的情况。结语指出继续研究此虫的生物学意义。  相似文献   

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It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.  相似文献   

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Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.  相似文献   

18.
Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.  相似文献   

19.
肝癌中HBV和HCV基因和抗原的分布及意义   总被引:1,自引:0,他引:1  
采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细  相似文献   

20.
For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.  相似文献   

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