Redescription of Camallanus hypophthalmichthys Dogel and Akhmerov, 1959 (Nematoda : Camallanidae) and its first record from fishes in China

The nematode Camallanus hypophthalmichthys Dogel and Akhmerov, 1959 is redescribed from specimens collected from the intestine of the bighead carp Aristichthys nobilis, from Liangzihu Lake (Yangtze River basin), Hubei Province, central China. The light and scanning electron microscopical examination made it possible to study in detail the morphology of this so far little-known species and to confirm its validity. The main specific features of C. hypophthalmichthys distinguishing it from the most similar Camallanus spp. is the presence of 3 small caudal processes on the male tail tip, 13-16 longitudinal ridges on the inner surface of the valve of the buccal capsule, and the arrangement of preanal and postanal genital papillae in the male. This finding represents a new host record, the first record of this parasite in the Yangtze River basin, and the first documented record of C. hypophthalmichthys from China. Camallanus hypophthalmichthys is considered a specific intestinal parasite of fishes of the cyprinid Hypophthalmichthyinae.

中国新疆塔里木河中下游河流廊道的景观生态学研究

中国西部干旱区是干旱区研究的天然实验场。塔里木河是西部干早区重要的生态河流。塔里木河中下游尉犁一若羌段以沙地景观为基质，以河渠、公路、防护林为连接廊道，草地、盐碱地、湿地、耕地为镶嵌斑块，是典型的干旱区河流廊道景观区域，是南疆第一大城市库尔勒与未来重建的新楼兰的唯一景观廊道，在塔里木河流域的可持续发展中起着重要的连通作用。本文以塔里木河下游绿色走廊为主体的塔里木河中下游河流廊道区域为研究对象，在区域景观生态特征的认识和景观生态建设方略的探讨上，具有重要意义。本文在景观生态学的应用研究中，注重其理论体系的构建。（1）全面收集国内外景观生态学研究的最新进展，提出景观生态学研究的核心研究框架与原理，阐明景观生态学研究的热点和新的领域。干旱区多功能景观研究，有着极其广阔的理论与实践上的创新潜力。根据以往研究成果，揭示中国西部干旱区的景观生态特征，展望其关键研究领域的前景和方向，其中绿洲研究、湿地研究、廊道研究和景观生态建设研究，各具特有的角度，又有相互的联系，最具景观生态学研究的特质和潜质。（2）收集卫星影像资料并进行解译（1980年MS航片校正、1990年TM、2000年TM），以土地利用类型为基础，以塔里木河中下游河流廊道区域现状为参照，建立了干早区河流廊道景观区域景观生态分类体系，结合野外植被和土壤调查，以及相关图件，全面研究了各类研究区景观的土壤和植物生态属性与功能特征。（3）通过景观格局指数的计算，以及景观类型的转换矩阵，揭示20世纪80年代以来区域廊道景观格局的变化过程与趋势，结合区域水资源、生态及人文变化，对变化的驱动力因子进行研究。在区域景观尺度上，构建景观生态空间分析模式，包括格局指数分析、转移矩阵分析和空间过程分析，并以此寻求区域景观格局变化的驱动力。（4）应用景观生态学原理，确定景观生态功能区划的原则，构建其区划系统。据此划分了三个景观生态功能类型区：①尉犁一卡拉水库段塔里木河一孔雀河中游城镇一绿洲农业区，②卡拉水库一大西海子水库塔里木河下游上中段农垦绿洲区，③大西海子水库一台特玛湖一若羌塔里木河下游下段一车尔臣河下游生态重建和恢复区。通过景观格局指数，对比不同功能区的景观生态差异；根据不同景观生态功能区，不同宽度的河流廊道缓冲带景观格局指数的分析，以及次一级廊道指数的计算，揭示景观廊道区域相关指数的变化规律及其廊道效应。（5）根据干旱区景观生态特点，建立干旱区生态环境质量评价概念模型，以研究区为案例，提出基于遥感和GIS的景观生态环境质量现状与预警指标体系，采用层次分析法，对塔里木河中下游以河流廊道为特征的研究区域进行景观生态评价分析。（6）在了解廊道区域景观时空变化驱动力的基础上，对不同的生态治理方式的景观生态效应进行分析，提出塔河中下游河流廊道区域“大塔里木河”景观生态建设的总体原则（包括减少对沙地基质的干扰，充分利用和适度开发草地资源，保护和恢复湿地景观的多功能性，畅通输水过程以稳定和增加植被覆盖及其多样性与经济性，通过节水灌溉和重视排水减轻次生盐渍化程度），及其相应的景观生态工程设计，确定不同景观生态功能区的景观生态建设与设计的模式与途径（包括生态恢复、生境更新与调整、生态功能重建和生态移民）。

黄土高原沟沿线的廊道防蚀效应探析

在分析黄土高原地区的沟沿线、沟沿线上下沟间地和沟谷地土壤侵蚀特征、小流域泥沙来源、坡沟侵蚀产沙关系的基础上,结合廊道的生态功能和以往的研究结果,认为在沟沿线的上部建立草灌与整地工程措施相结合的植物廊道,来拦蓄阻截沟间地的来水来沙,可使流域的土壤侵蚀量减少54．5%～77．0%。

A new spirofilid ciliate from the yellow sea: Metastrongylidium distichum n gen, n sp (ciliophora, stichotrichia)

The morphology and infraciliature of a new ciliate, Metastrongylidium distichum, isolated from the Yellow Sea, are investigated using live observation and protargol impregnation. Metastrongylidium distichum is about 170 x 40 pm in vivo, clavate to elongate ellipsoidal with bluntly pointed posterior end, and has two macronuclear nodules, six distinctly large buccal and frontal cirri, three dorsal kineties and two each of spiralled ventral and marginal cirral rows. These features indicate a generic allocation in Strongylidium Sterki, 1878. However, the new ciliate has a distinct feature not recognizable in Strongylidiurn, viz., the presence of (three or four) transverse cirri. Thus, we propose a new genus Metastrongylidium for the new species, M distichum nov. gen., n. sp. Metastrongylidium belongs to the family Spirofilidae, where it differs from Mucotrichidium by the lack of postperistomial cirrus and the different frontal and ventral cirral pattern. Metastrongylidium distichum is easily distinguishable from the seemingly similar species Strongylidium californicum Kahl, 1932 by the macronuclear pattern (invariably 2 vs. many nodules). It highly resembles the poorly known species S. contortum (Gelei 1954) Borror, 1972 in the body outline and nuclear pattern, differing in the biotope, the posterior cirral pattern, and the arrangement of right marginal row.

Kiitricha minuta n. Sp., a peculiar hypotrichous ciliate (Ciliophora, Spirotrichea) from the Yellow Sea

The morphology and infraciliature of a new ciliate, Kiitricha minuta n. sp., isolated from the Yellow Sea, were investigated using live observation and protargol impregnation. Kiitricha minuta represents a third member of the rarely known order Kiitrichida. It is unique in the subclass Hypotrichia in having many rows of small uniform cirri along the right side of the body and the dorsal kineties composed of dikinetids, most of which bear two cilia. Kiitricha minuta n. sp. is ovoid and measures about 60 x 45 mu m in vivo. It has a huge buccal cavity occupying about 80% of the body length, numerous body extrusomes, one macronucleus and two micronuclei, 27-27 adoral membranelles, 9-12 frontoventral cirral rows, a submarginal row of 7-9 cirri, 6 or 7 transverse cirri, and roughly 7-9 dorsal kineties. This new species differs distinctly from its only congener Kiitricha marina by its smaller size (60 mu m vs. 80-150 mu m), the presence of body extrusomes (vs. absent), the different macronuclear pattern (one vs. two nodules), and the lower number of frontoventral cirral rows (9-12 vs. 21-26), which terminate at the anterior two-thirds of body (vs. extend to the posterior). The new term "submarginal cirral row" is introduced to distinguish from the marginal cirral row in typical hypotrichs sensu lato. Based on our new observations and the literature, an improved diagnosis for the genus Kiitricha is provided and its phylogenetic importance is discussed.

Group size effects on foraging and vigilance in migratory Tibetan antelope

Large group sizes have been hypothesized to decrease predation risk and increase food competition. We investigated group size effects on vigilance and foraging behaviour during the migratory period in female Tibetan antelope Pantholops hodgsoni, in the Kekexili Nature Reserve of Qinghai Province, China. During June to August, adult female antelope and yearling females gather in large migratory groups and cross the Qinghai-Tibet highway to calving grounds within the Nature Reserve and return to Qumalai county after calving. Large groups of antelope aggregate in the migratory corridor where they compete for limited food resources and attract the attention of mammalian and avian predators and scavengers. We restricted our sampling to groups of less than 30 antelopes and thus limit our inference accordingly. Focal-animal sampling was used to record the behaviour of the free-ranging antelope except for those with lambs. Tibetan antelope spent more time foraging in larger groups but frequency of foraging bouts was not affected by group size. Conversely, the time spent vigilant and frequency of vigilance bouts decreased with increased group size. We suggest that these results are best explained by competition for food and risk of predation. (C) 2007 Elsevier B.V. All rights reserved.

鄂尔多斯盆地西缘中生代构造与地层分析及盆地演化研究

Through the detailed analyses of Mesozoic tectono-stratigraphy and basin formation dynamic mechanism and the styles of different units in the western margin of Ordos Basin(Abbreviated to "the western margin"), while some issues of the pre-Mesozoic in the western margin and central part of Ordos Basin also be discussed, the main views and conclusion as follows: 1. There are three types of depositional systems which are related with syndepositional tectonic actions and different tectonic prototype basins, including: alluvial fan systems, river system (braided river system and sinuosity river system), lacustrine-river delta system and fan delta system. They have complex constitutions of genetic facies. For the tectonic sequence VI, the fan sediments finning upper in the north-western margin and coarse upper in the south-western margin respectively. 2. In order to light the relationship between basin basement subsidence rate and sediment supply and the superposed styles, five categories of depositional systems tracts in different prototype basins were defined: aggrading and transgressive systems tracts during early subsidence stage, regressive and aggrading systems tracts during rapid subsidence, upper transgessive systems tracts during later subsidence stage. Different filling characteristics and related tectonic actions in different stages in Mesozoic period were discussed. 3. In order to determined the tectonic events of the provenance zones and provenance strata corresponding to basins sediments, according the clastics dispersal style and chemical analyses results of sediments in different areas, the provenance characteristics have been described. The collision stage between the "Mongolia block" and the north-China block may be the late permian; The sediments of Mesozoic strata in the north-western margin is mainly from the Alex blocks and north-Qilian Paleozoic orogeny, while the south-western margin from Qinling orogeny. The volcanic debris in the Yan'an Formation may be from the arc of the north margin of north-China block, although more study needed for the origin of the debris. The provenance of the Cretaceous may be from the early orogeny and the metamorphic basement of Longshan group. 4. The subsidence curve and subsidence rate and sedimentary rate in different units have been analyzed. For different prototype basin, the form of the subsidence curves are different. The subsidence of the basins are related with the orogeny of the basins.The beginning age of the foreland basin may be the middle Triassic. The change of basement subsidence show the migration of the foredeep and forebulge into the basin. The present appearance of the Ordos basin may be formed at the late stage of Cretaceous, not formed at the late Jurassic. 5. The structure mode of the west margin is very complex. Structure transfer in different fold-thrust units has been divided into three types: transfer faults, transition structures and intersected form. The theoretic explanations also have been given for the origin and the forming mechanism. The unique structure form of Hengshanpu is vergent west different from the east vergence of most thrust faults, the mechanism of which has been explained. 6. In Triassic period, the He1anshan basin is extensional basin while the Hengshanbu is "forland", and the possible mechanism of the seemingly incompatible structures has been explained. First time, the thesis integrate the Jurassic—early Cretaceous basins of west margin with the Hexi corridor basins and explain the unitive forming mechanism. The model thinks the lateral extrusion is the main mechanism of the Hexi corridor and west margin basins, meanwhile, the deep elements and basement characters of the basins. Also, for the first time, we determine the age of the basalt in Helanshan area as the Cretaceous period, the age matching with the forming of the Cretaceous basins and as the main factor of the coal metamorphism in the Helanshan area. 7. The Neoprotterozoic aulacogen is not the continuation of the Mesozoic aulacogen, while it is another new rift stage. In the Paleozoic, the Liupanshan—southern Helanshan area is part of the back-arc basins of north Qilian ocean. 8. The Helanshan "alacogen" is connected with the north margin of north China block, not end at the north of Zhouzishan area like "appendices". Also, I think the upper Devonian basin as the beginning stage of the extensional early Carboniferous basins, not as a part of the foreland basins of Silurian period, not the collision rift. 9. The controlling factor of the difference of the deformation styles of the north-west margin and the south-west margin is the difference of the basements and adjacent tectonic units of the two parts.