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71.
1992年11月15日从云南省河口县城自由市场的一位越南人手中买得一雌性巨蜥,经鉴定为一新种,定名为越南巨蜥Varanusvietnamensis。鉴别特征:新种背部鳞片光滑,仅在后半部插有极少的起棱鳞片,不同于V.nebulosus(Boulenger,1885,1890;Taylor,1963);新种不同于V.salvator在于其背部没有眼斑状横斑带(ocellimarks)(Guenther,1864;Harrison等,1957;Pope,1935);不同于V.irrawardicus(Yang等,1987),V.griseus和V.monitor(Smith,1935)在于有6─7个横向扩大的眼上鳞。文中运用了15个外部性状对产于南亚,东南亚大陆及岛屿共9个种(含新种)的种间亲缘关系进行了研究,结果认为,种间亲缘关系的亲疏与分布地区相距的远近成正相关。  相似文献   
72.
云南小孢发属地衣的分类   总被引:3,自引:0,他引:3  
报道了云南小孢发属地衣13种,其中中国新记录种6个,它们是:喜马拉雅小孢发,尼泊尔小孢发,光滑小孢发,光亮小孢发,多叉小孢发,波氏小孢发,另外7种的形态及分布也在文中进行了讨论。  相似文献   
73.
描写了西藏墨脱县的9个新种和两个新变种,它们是墨脱油丹、西藏球楠、扁果木姜子、勃生木姜子、少花木姜子、树志木姜子、柔毛长蕊木姜子(变种)、西藏新木姜子(变种)、纤枝钓樟等。  相似文献   
74.
The distribution of the New Zealand flatworm (Artioposthia triangulata) in Scotland was surveyed between July 1991 and February 1993. There were 348 records from domestic gardens, 56 from botanic gardens, garden centres and nurseries, with only 13 from farms. Although most of the records came from around the major cities the flatworm was found to have become established throughout the Scottish mainland and some of the Islands, e.g. Bute, Gigha, Orkney and Skye. The impact of the flatworm on earthworm populations in agricultural land in Scotland was, as yet, found to be minimal but the fact that seven adjacent farms near Dunoon were infected suggested it could be spread from farm to farm and that in the West of Scotland it could become widespread in agricultural land.  相似文献   
75.
Information on the ecology of New Guinea streams is meagre, and data are needed on the trophic basis of aquatic production in rivers such as the Sepik in Papua New Guinea which have low fish yields. This study investigates the relationship between riparian shading (from savanna grassland to primary rainforest), algal and detrital food, and macroinvertebrate abundance and community structure in 6 Sepik River tributary streams. A particular aim was to elucidate macroinvertebrate community responses to changes in riparian conditions. All streams supported diverse benthic communities, but morphospecies richness (overall total 64) was less than in streams on the tropical Asian mainland; population densities of benthic invertebrates, by contrast, were similar to those recorded elsewhere. Low diversity could reflect limited taxonomic penetration, but may result from the absence of major groups (Plecoptera, Heptageniidae, Ephemerellidae, Psephenidae, Megaloptera, etc.) which occur on the Asian mainland. Population densities of all 19 of the most abundant macroinvertebrate taxa varied significantly among the 6 study streams, but community composition in each was broadly similar with dominance by Baetidae and (in order of decreasing importance), Leptophlebiidae, Orthocladiinae, Elmidae and Hydropsychidae. Principal components analysis (PCA) undertaken on counts of abundant macroinvertebrate taxa clearly separated samples taken in two streams from the rest. Both streams contained high detrital standing stocks and one was completely shaded by rainforest. Stepwise multiple-regression analysis indicated that population densities of the majority of abundant taxa (11 out of 19) across streams (10 samples per stream; n = 60) were influenced by algae and/or detritus, although standing stocks of these variables were not clearly related to riparian conditions. When regression analysis was repeated on mean counts of taxa per stream (dependent variables) versus features of each stream as a whole (thus n = 6), % shading and detritus were the independent variables yielding significant regression models most frequently, but pH, total-nitrogen loads and algae were also significant predictors of faunal abundance. Further regression analysis, undertaken separately on samples (n = 10) from each stream, confirmed the ability of algae and detritus to account for significant portions of the variance in macroinvertebrate abundance, but the significance of these variables varied among streams with the consequence that responses of individual taxa to algae or detritus was site-specific.Community functional organization — revealed by investigation of macroinvertebrate functional feeding groups (FFGs) — was rather conservative, and streams were codominated by collector-gatherers (mean across 6 streams = 43%) and grazers (36%), followed by filter-feeders (15%) and predators (7%). The shredder FFG was species-poor and comprised only 0.4% of total macroinvertebrate populations; shredders did not exceed 2% of benthic populations in any stream. PCA of FFG abundance data was characterized by poor separation among streams, although there was some evidence of clustering of samples from unshaded sites. The first 2 PCA axes accounted for 84% of the variation in the data suggesting that the poor separation resulted from the general similarity of FFG representation among streams. Although stepwise multiple-regression analysis indicated that algae and detritus accounted for significant proportions of the variations in population density and relative abundance of some FFGs, the response of community functional organization to changes in riparian conditions and algal and detrital food base was weak — unlike the deterministic responses that may be typical of north-temperate streams.  相似文献   
76.
77.
作者在武陵山地区的鱼类寄生线虫调查工作中,发现一种毛细线虫,经研究,为一新种,定名为岁新毛细线虫,新种(Neocapillariaphoxinisp.nov.)。根据其特征,为此建立一新属──新毛细线虫属。  相似文献   
78.
武陵山地区鱼类寄生杆咽属线虫两新种   总被引:1,自引:0,他引:1  
本文报道在武陵山地区的白甲鱼[(Varicorkinus(Onychostoma)simus(SauvageetDabry)]和沪溪直口峻(RectorisluxiensisWuetYao)中发现的两种杆咽属(Rhabdochona)线虫新种,定名为白甲鱼杆咽线虫,新种(RhabdOchonaonyrkostomisp.nov.)和短咽杆咽线虫,新种(RhabdOchonabrevichonasp.nov.),并对两新种进行了测量和详细的描述。  相似文献   
79.
Chloroplast DNA restriction site variation was examined for 35 taxa in theVernonieae and four outgroup tribes, using 17 restriction enzymes mapped for ca. 900 restriction sites per species; 139 mutations were found to be phylogenetically informative. Phylogenetic trees were constructed using Wagner and weighted parsimony, and evaluated by bootstrap and decay analyses. Relationships of Old and New World taxa indicate complex geographical relationships; there was no clear geographic separation by hemisphere. The relationships between Old and New World Vernonias found here support prior morphological analyses. The sister group to all New and most Old World taxa was composed of a small group of Old World species including yellow-flowered, trinervate-leaved species previously postulated to be basal in the tribe. The majority of both New and Old World taxa are derived from a lineage beginning with the monotypic genusStokesia, an endemic of the southeastern United States. The genusVernonia was also found to be paraphyletic within both the New and Old World. Available data do not support either the separation ofVernonia or the tribeVernonieae into geographically distinct lineages. The pattern of relationships within theVernonieae for taxa from North America, Asia, Africa, Central and South America is most similar to that of several other groups of both plants and animals with a boreotropical origin, rather than an origin in Gondwanaland. Such a pattern of distribution suggests more ancient vicariant events than are routinely postulated for theAsteraceae.  相似文献   
80.
湖南省蹄盖蕨科新分布   总被引:2,自引:0,他引:2  
报道在湖南省新发现的蹄盖蕨科植物10属,36种。  相似文献   
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