涡虫的采集培养和切割再生方法

迄今,我国的淡水涡虫已发现七种,其中最常见的是东亚三角头涡虫(Dugesis iaponicua),分布于香港、台湾、昆明直到吉林省境内,和细形山地涡虫(Phagocato vivida),分布于大、小兴安岭和长白山一带。七种淡水涡虫都喜生于冷泉溪流的石下。采集涡虫时,途中要防止水温的骤升。制作切片的涡虫采集,需将涡虫用稀酸杀生,鲍氏液固定,然后放酒精中带回。用带盖的塘瓷盘加水培养涡虫,既接近生境,便于实验操作和换水,又能使涡虫较好的生殖和产卵。切割再生实验,既能定向地培育出双头、双尾、多头和多尾的畸型涡虫,又能增加超常数眼涡虫出现的频率。     

我国的淡水涡虫

扁形动物门的代表动物是涡虫纲的三肠目淡水(三肠)亚目涡虫。这类涡虫全世界发现了近40属和近400种,它们归属于4个科,即三角头涡虫科(Dugesiidae)、扁平涡虫科(Planariidae)、洞穴涡虫科(Kenkiidae)和树枝肠涡虫科(Dendrocoelidae)。它们遍布于全世界各地的泉溪、湖沼、池塘、水井和洞穴水中。它们的分布区域极不均衡,北半球的温带、亚寒带地区较多,其中仅分布于贝加尔     

我国涡虫纲分类学的研究

我国涡虫纲分类学的研究李光鹏（黑龙江省科学院自然资源研究所哈尔滨１５００４０）关键词涡虫，涡虫纲，分类学扁形动物门涡虫纲动物生活在海洋、淡水和潮湿的土壤中。多数营自由生活，少数为共生或寄生生活。是一类种类繁多，形态、大小、色泽和栖息环境多样性的动物［...     

管大口涡虫生物学特性的观察

报道了分布于安徽、广东和福建一带的大口涡虫属管大口涡虫(Macrostomum tubo)的生物学特性。该涡虫生活于淡水池塘、小河的水生植物的叶子反面。在实验室观察了该涡虫的生活习性。介绍了常年饲养和繁殖管大口涡虫的方法。通过不同方向的连续切片,描述了该涡虫的形态结构。研究结果提示：大口涡虫是涡虫纲教学和动物进化研究的理想实验材料。     

淡水涡虫研究进展

淡水涡虫研究进展韩志泉（首都师范大学生物系北京１０００３７）关键词分类，繁殖，再生淡水涡虫研究，可追溯到１８９０年，从本世纪７０年代以来，研究日趋深入，本文拟从四个方面于以回顾。１组织形态涡虫形态学如今已向微观世界纵深发展，这方面Ｂａｇｕｎａ等［１］...     

淡水三肠目涡虫的染色体研究进展

三肠目(Tricladida)淡水亚目(Paludi-cola)属于扁形动物门涡虫纲,共分四个科:三角头涡虫科(Dugesiidae)、扁平涡虫科(Planariidae)、树枝肠涡虫科(Dendrocoe-lidae)和洞穴涡虫科(Kenkiidae)。全世界已经发现35个属387种。除洞穴科涡虫尚未     

中国淡水三角涡虫染色体组型的研究

采用压片法对不同产地的淡水三角涡虫染色体进行研究,结果表明,湖北省武汉市珞珈山的淡水三角涡虫体细胞中有16条染色体,为二倍体（2n=2x=16m）;江苏省太湖东山岛的淡水三角涡虫体细胞中有24条染色体,为三倍体（2n=3x=24m）;贵州省遵义市凤凰山的淡水三角涡虫体细胞同时存在24条染色体和16条染色体两种分裂相,为混倍体。本文根据组型分析的结果对上述三个产地淡水三角涡虫的分类和染色体倍性进行了初步研究。另外,本研究中还发现涡虫染色体倍性的变化与涡虫生殖方式的转变以及环境温度有一定的联系。     

中国小达氏涡虫和大变杰氏涡虫的生物学特性

对单肠目(Rhabdocoela)达氏科(Dalyelliidae)的中国小达氏涡虫(Microdalyellia sinensis)和大变杰氏涡虫(Gieysztoria macrovariata9-spinosa)进行了长期饲养与观察,了解和比较这两种涡虫的习性、繁殖、发育及组织学特点。结果表明,中国小达氏涡虫比大变杰氏涡虫反应敏捷,生殖器官的形态位置有明显区别;中国小达氏涡虫产卵周期约5 d,每期产卵10.5枚;大变杰氏涡虫产卵周期约10 d,每期产卵22.3枚;两种涡虫卵孵化期约60 h,发育成熟期9 d左右;最后探讨了卵胚非正常发育与雌雄生殖器官成熟期,以及涡虫的淡水生态学意义等问题。     

我国的淡水涡虫

阐述了我国淡水涡虫的生活环境、采集培养方法、形态特点及生物学特性,报导了我国已知的淡水涡虫１０属２１种,以期为我国淡水虫分类区系研究脏这课堂教学提供基础资料,促进访学科的发展。     

中国的淡水（三肠目）涡虫

三肠目淡水涡虫是一类扁形动物门(Phylum Platyhelminthes)涡虫纲(Class Turbellaria)三肠目(Order Tricladida)淡水亚目(Suborder Paludicola)涡虫。由于它是扁形动物门和涡虫纲的代表动物,是动物学研究的重要材料;又是教学中不可缺少的实验标本,所以一直受到全世界生物学家和院校师生们的关注,一直是世界各国涡虫分类学家研究的热门。肯克(Kenk 1978;参见M.Kawakatsu,1978)     

Chromosomal evolution in marine triclads and polyclads (Turbellaria)

From an analysis of chromosomal mutations in seven species among five genera of marine triclads and polyclads, three different types of mechanisms of such mutations are identified: 1) rearrangement involving the centromere such that its position is changed, 2) rearrangement of whole chromosome arms, and 3) Robertsonian mechanisms. These mechanisms are the same as those reported for freshwater turbellarians, but aneuploidy and polyploidy, which are common in freshwater species, were not detected in these marine turbellarians.     

Temporary pools are not `enemy-free'

Temporary pools are traditionally considered as refuges where the conspicuous anostracans are protected from predation. While this is true for the size-selective predation by fish, there is compelling evidence that invertebrate predation is an important biotic stress regulating temporary pool communities. In rock pools in southeastern Botswana, we studied the impact of some suspected invertebrate predators on populations of the freshwater anostracan Branchipodopsis wolfi by means of observations and manipulative experiments. In a survey of 45 pools, the relationship between B. wolfi natural population sizes and the abundance of suspected predators were never negative for turbellarians and mosquito larvae. When dragonfly larvae, notonectids or tadpoles were present, the anostracan populations were generally non-existent or very small. In enclosure experiments with turbellarians, there was a significant effect of predation within one hour of the start; the average daily predation rate was about 1/4 anostracan per turbellarian. Anostracans from a pool with few turbellarians were slightly less vulnerable than those from a turbellarian-rich pool. Furthermore, there was an indication of males being predated on more than females. With dragonfly larvae and notonectids, the predation effect was marked with all six anostracans in an experiment eaten in less than one day by a single predator (predation rate: about one anostracan every 2 h per predator). In a behavioral study, both sexes of B. wolfi avoided swimming above sediment that held more turbellarians than the open patches; there was no evidence for chemical communication with respect to this behavior.     

Ultrastructural features of oogenesis in some marine neoophoran turbellarians

An ultrastructural study of oogenesis has been undertaken in some marine species of neoophoran turbellarians belonging to the Tricladida, Proseriata, and Prolecithophora. Among marine triclads, Cercyra hastata has oocytes with a remarkable amount of what appears to be autosynthetic proteinaceous yolk, while Procerodes dohrni and P. lobata have alecithal oocytes. Among the Proseriata, several species of the primitive family Monocelididae (subfamily Monocelidinae) have oocytes with a discrete amount of what appears to be autosynthetic yolk, while Parotoplana macrostyla, of the derived family Otoplanidae, has alecithal eggs. Finally preliminary observations on Plagiostomum maculatum (order Prolecithophora) suggest that oocytes have autosynthetic yolk globules.These results support the hypothesis (previously formulated on the basis of similar ultrastructural investigations on freshwater triclads) that the presence of autosynthetic yolk in some neoophoran turbellarians can be interpreted as a primitive character inherited from an ancestor with archoophoran organization. This plesiomorphic character would still be maintained in some species while lost in others following differentiation of vitellaria which are characteristic of the Neoophora.     

Turbellarian assemblages in freshwater lagoons in southern Brazil

Turbellarians, which typically feed on bacteria, algae, rotifers, oligochaetes, dipteran larvae, microcrustaceans, and other organisms, are abundant in diverse types of wetlands. Despite their importance, abundance, and species richness in freshwater environments, turbellarians are seldom considered in studies on biodiversity. We analyzed the structure of turbellarian communities in shore areas of three categories of permanent wetlands classified according to their perimeter as small, intermediate, and large during an annual cycle. In total, 1847 turbellarians were collected representing 42 species and 15 genera, from the orders Catenulida, Macrostomida, Lecithoepitheliata, Rhabdocoela, and Tricladida. Sixteen species were common to the three categories of wetlands, whereas nineteen species were unique to a particular category. Species composition varied among wetlands of different sizes; small, intermediate, and large wetlands had different dominant species. We found seasonal differences in community composition over the year, but no significant differences in mean values of observed species richness among wetlands with different sizes and among seasonal samples. The estimated species richness was, however, higher in the small wetlands, followed by the large and intermediate wetlands. In the summer, abundance was significantly lower in the small water bodies than in the intermediate and large bodies of water. Our results reinforce the need for conservation of wetlands of different sizes.     

退耕还林还草工程对陕北地区生态系统服务价值时空演变的影响

基于陕北地区1990、2000、2015年土地利用数据，运用单位面积生态系统价值当量因子法、格网法、探索性空间数据法（ESDA），分析了退耕还林还草工程实施前后生态系统服务价值（ESV）的空间分布和演化规律，探讨了退耕还林还草工程对ESV的影响。结果表明：（1）陕北地区退耕还林还草工程实施效果显著，工程实施后共有297066.15 hm2耕地转化为林地和草地，林草覆盖率由57.33%增长至60.50%。（2）退耕还林还草工程使得陕北地区ESV得到了显著提升。25年间陕北地区ESV共增加了32.82亿元，ESV在工程实施后比工程实施前多增加了5.93亿元，增长主要源于退耕引起林地和草地面积的增加。（3）ESV空间分布上呈显著的“南高北低”分布格局，并表现出正向的集聚性和依存性，ESV热点区和冷点区集聚效果明显，热点区集聚与林地、草地的空间分布相吻合，冷点区集聚与未利用地、耕地和建设用地的空间分布相吻合。（4）受退耕还林还草工程影响，陕北地区中部中等等级和次高ESV分布区域逐渐增大、次热点区空间集聚性逐渐增强，北部次低等级和低等级ESV分布区域逐渐减少、冷点区空间集聚性逐渐减弱。整体而言，陕北地区土地利用类型转移和ESV的增减变化与推行退耕还林还草工程在时间上相呼应、在空间上相匹配，退耕还林还草工程实施使得陕北地区生态环境得到了有效改善，ESV得到了显著提升。     

Fine-scale north-to-south genetic admixture profile in Shaanxi Han Chinese revealed by genome-wide demographic history reconstruction

The Han Chinese are the world's largest ethnic group residing across China. Shaanxi province in northern China was a pastoral–agricultural interlacing region sensitive to climate change since Neolithic times, which makes it a vital place for studying population dynamics. However, genetic studies of Shaanxi Han are underrepresented due to the lack of high-density sampling and genome-wide data. Here, we genotyped 700 000 single nucleotide polymorphisms (SNPs) in 200 Han individuals from nine populations in Shaanxi and compared with available modern and ancient Eurasian individuals. We revealed a north–south genetic cline in Han Chinese with Shaanxi Han locating at the northern side of the cline. We detected the western Eurasian-related admixture in Shaanxi populations, especially in Guanzhong and Shanbei Han Chinese in proportions of 2%–4.6%. Shaanxi Han were suggested to derive a large part of ancestry (39%–69%) from a lineage that also contributed largely to ancient and present-day Tibetans (85%) as well as southern Han, supporting the common northern China origin of modern Sino-Tibetan-speaking populations and southwestward expansion of millet farmers from the middle-upper Yellow River Basin to the Tibetan Plateau and to southern China. The rest of the ancestry of Shaanxi Han was from a lineage closely related to ancient and present-day Austronesian and Tai-Kadai speaking populations in southern China and Southeast Asia. We also observed a genetic substructure in Shaanxi Han in terms of north–south-related ancestry corresponding well to the latitudes. Maternal mitochondrial DNA and paternal Y-chromosome lineages further demonstrated the aforementioned admixture pattern of Han Chinese in Shaanxi province.     

Nahrungsbeziehungen der Turbellarien in Küstensalzwiesen

Turbellarians represent one of the most characteristic and often also most numerous elements of the salt-marsh biocoenosis. The analysis of their food relations promised, therefore, insights into the food web in salt marshes. Two questions are of particular importance: (1) Is autochthonous or allochthonous food more important? (2) Are there noticeable relations to the aerial phase of the biotope? Gut-content surveys, feeding-experiments and information from literature indicate, that the main food of salt-marsh turbellarians consists of oligochetes, nematodes and diatoms. There exist certain relations between the taxonomic categories of turbellarians and their food sources, and, furthermore, between the type of pharynx and the kind of food. Oligochetes are 4 and nematodes up to 14 times more abundant than turbellarians. Nematodes are also likely to be the most important food competitors for turbellarians. Enemies of salt-marsh turbellarians are the polychaeteNereis diversicolor and sporozoan parasites. The main food of salt-marsh turbellarians consists of organisms existing in sufficient numbers in the biotope; a dependency on allochthonous food is therefore unlikely. Allochthonous food (e. g. copepods from adjacent mud flats) may, however, at times enlarge the food resources available. Little evidence for the use of air-living organisms as food, and no evidence for air-living enemies, was found. The aquatic food chain in salt marshes ends at the level of flatworm-eating polychaetes or, where these are absent, already at that of the turbellarians themselves. Although the biomass (standing crop) of primary producers reaches its maximum in the most protected part of the beach (salt marshes), maximum population density of turbellarians is found in parts of maximum exposure. This fact is considered to be due to the great amount of allochthonous food available at the upper edge of the surf zone.     

2000-2010年陕西北部不同类型草地面积及其覆盖度变化

利用生态系统分类及生态参量数据产品,运用植被覆盖度年际变异系数、趋势斜率和退化指数等草地覆盖度变化状况评价指标,对陕西北部重大生态建设工程实施关键年份（2000-2010年）内各类型草地植被覆盖度的演替状况进行研究。结果显示：（1）延安市和榆林市的黄土沟壑区草地生态系统面积明显增加,年均植被覆盖度由2000年的27.94%增长到2010年的40.50%,草地覆盖度整体由低覆盖向中覆盖等级转变,其中温带草原和温性草丛覆盖度呈明显上升趋势。（2）陕西北部大部分草地覆盖度波动变化明显,延河以北温带草原稳定性低,延河以南温性草丛稳定性较高、波动变化较小;93.98%的草地区域覆盖度呈上升趋势,其中极显著上升区域主要分布在黄土沟壑区;3.23%的降低区域集中于榆林市西北部的温带荒漠草原分布区。（3）11年间,陕西北部退化草地得到改善恢复的面积由2000-2005年期间的9594.44 km²增加到2005-2010年期间的26 544.39 km²,远大于退化区域,草地极重度退化程度得到扭转。本研究表明陕西北部不同类型草地覆盖度均不同程度得到了缓解和改善。     

Peptidergic signalization: An immunocytochemical study of FMRF-related peptides in the nervous system of planarians

Free-living freshwater flatworms, planarians, are well known biological object. Due to their unprecedented regenerative ability, planarians attract the particular attention of scientists. From a small body piece planarians can regenerate a whole organism including central nervous system and all organs and tissues. Employment of modern immunocytochemical methods in conjunctions with confocal laser scanning microscopy (CLSM) made it possible to discover a spectrum of neuronal substances in the nervous system of relatively simple animals. In the present study, specific fluorescently labeled antibodies have been used for identification of FMRF-related neuropeptides in the nervous system of three planarian species: Schmidtea mediterranea, Girardia tigrina, and Polycelis tenuis (Platyhelminthes, Turbellaria). The details of the FMRF-like immunostaining have been described and completed. Some previously published data concerning neuronal signalization in turbellarians have been observed.     

基于SPOT-VGT NDVI的陕北植被覆盖时空变化

利用1998-2010年SPOT-VGT NDVI影像对陕北地区植被的时空变化进行分析.结果表明:研究期间,陕北地区归一化植被指数(NDVI)的季相变化明显,月均最高值出现在8月、最小值出现在1月,月均值的变化幅度在0.14 ～0.46,NDVI月均值为0.28,其年均值总体呈上升趋势;在空间上,植被改善地区集中于陕北中南部,生态环境退化区域集中在长城以北风沙区;气温和降水是影响植被变化的重要气候因子,其与NDVI变化的相关系数分别为0.72和0.58;植被改善明显的区域主要位于坡度15° ～25°的地区,反映出国家退耕还林还草工程对陕北地区生态环境的恢复和改善起到了巨大作用.