广西隆林祥播地区中、晚二叠世有孔虫动物群     

周铁明 《南方国土资源》1998,(2)

文章研究了广西隆林祥播地区中二叠统茅口阶,上二叠统吴家坪阶,长兴阶的有孔虫动物群,计有２２属５５种,７个未定种,分属于５个超科中的１２科。并由下而上建立５个有孔虫组合,介绍了各组合特征。  相似文献   

对陕西蓝田几个哺乳动物群的层位及时代的新认识     

李传令  薛祥煦 《地层学杂志》1998,22(2):81-86

过去认为涝池河—阳郭动物群的时代相当或稍晚于泥河湾动物群,早于公王岭动物群,厚镇涝池河动物群的时代与公王岭动物群的一致。但各动物群的层位及在动物群演化上所处的位置表明涝池河—阳郭动物群的时代应与公王岭动物群的一致,比泥河湾动物群的晚,而厚镇涝池河动物群的时代应与陈家窝动物群的相当。重新厘定了公王岭期与陈家窝期的涵义,认为蓝田黄土地层中、早更新统的界线应划在Ｓ８与Ｌ９交界处。  相似文献   

On the ecology of meiofauna in an organically polluted estuarine mudflat   总被引：1，自引：0，他引：1  

Lucas A. Bouwman  Karin Romeijn  Wim Admiraal 《Estuarine, Coastal and Shelf Science》1984,19(6):633-653

The structure, distribution and seasonal changes of the benthic meiofauna in an organically polluted, tidal, brackish-water mudflat in the Ems-Dollart estuary were analysed. Towards the outfall of polluted fresh water, macrofauna disappeared, numbers of meiofauna increased but the diversity of the meiofauna decreased. In the area surrounding the outfall the numbers and biomass of nematodes and oligochaetes increased rapidly in spring and remained high until autumn (c. 13 × 10⁶ individuals m⁻²; c. 2gCm⁻²). The benthic fauna comprised small numbers of species, dominated by a few fast-growing diatom-feeding nematodes (Eudiplogaster pararmatus and Dichromadora geophila) and oligochaetes (Amphichaeta sannio and Paranais litoralis). Eudiplogaster pararmatus exhibits brood care and it tolerates low salinities. Dichromadora geophila which is oviparous, behaved similarly regarding tolerances, life cycle and feeding but this species was less successful than Eudiplogaster in colonizing the mudflats near the outfall. The success of the two naidid oligochaete species results from their method of reproduction by means of binary fission.Most organisms fed on benthic diatoms. In spite of intensive mineralization in the mudflat, only one bacteria-feeding organism was found in abundance (the nematode Leptolaimus papilliger). The absence of macrofaunal organisms, e.g. Nereis diversicolor, is probably also responsible for the development of high densities of meiofauna in the upper sediment layers of the mudflats in the vicinity of the outfall.The heavy load of organic waste entering the Dollart reduced the diversity within the benthic ecosystem, but nevertheless a simple system remained, based on the recurrent reoxidation of the sediment surface.  相似文献   

山东省东平湖桡足类的初步研究   总被引：3，自引：0，他引：3  

林育真  李玉仙 《海洋湖沼通报》1997,(4):32-36

１９９４年，分别于枯水期，丰水期，平水期对东平湖桡足类群落结构进行了调查研究，同时探讨了东平湖桡足类区系结构特征。  相似文献   

东方鲀属鱼类的分类与区系分布研究   总被引：12，自引：0，他引：12  

王奎旗  陈梅  高天翔 《中国海洋大学学报(自然科学版)》2001,31(6):855-860

本文在调查与校核资料基础上 ,系统整理了 2 2种东方属鱼类的分类检索并附简图 ,报告了该属鱼类的区系性质与种类分布。文中在分类方面尚讨论了同物异名的订正 ,区系分布上提出了中日海区是世界该属鱼类的分布中心。最后对河豚毒的开发研究和中毒防治提出了意见和建议  相似文献   

The biology and ecology of a submarine cave: the Grotta del Bel Torrente (Central-East Sardegna, Italy)     

Anke Oertel  & Robert A. Patzner 《Marine Ecology》2007,28(S1):60-65

  相似文献   

Seasonal food web structures and sympagic-pelagic coupling in the European Arctic revealed by stable isotopes and a two-source food web model   总被引：3，自引：0，他引：3  

Janne E. Søreide  Haakon Hop  Stig Falk-Petersen 《Progress in Oceanography》2006,71(1):59-87

We simultaneously followed stable carbon (δ¹³C) and nitrogen (δ¹⁵N) isotopes in a two-source food web model to determine trophic levels and the relative importance of open water- and ice-associated food sources (phytoplankton vs. ice algae) in the lower marine food web in the European Arctic during four seasons. The model is based upon extensive seasonal data from 1995 to 2001.Phytoplankton, represented by samples of particulate organic matter from open water (Pelagic-POM) and ice algae, represented by samples from the underside of the ice (Ice-POM), were isotopically different. Ice-POM was generally dominated by the typical ice diatoms Nitzschia frigida and Melosira arctica and was more enriched than Pelagic-POM in ¹³C (δ¹³C = −20‰ vs. −24‰), but less enriched in ¹⁵N (δ¹⁵N = 1.8‰ vs. 4.0‰). However, when dominated by pelagic algae, Ice-POM was enriched in ¹³C and ¹⁵N similarly to Pelagic-POM.The derived trophic enrichment factors for δ¹⁵N (Δ_N = 3.4‰) and δ¹³C (Δ_C = 0.6‰) were similar in both pelagic and sympagic (ice-associated) systems, although the Δ_C for the sympagic system was variable.Trophic level (TL) range for zooplankton (TL = 1.8-3.8) was similar to that of ice fauna (TL = 1.9-3.7), but ice amphipods were generally less enriched in δ¹⁵N than zooplankton, reflecting lower δ¹⁵N in Ice-POM compared to Pelagic-POM. For bulk zooplankton, TLs and carbon sources changed little seasonally, but the proportion of herbivores was higher during May-September than in October and March. Overall, we found that the primary carbon source for zooplankton was Pelagic-POM (mean 74%), but depending on species, season and TL, substantial carbon (up to 50%) was supplied from the sympagic system. For bulk ice fauna, no major changes were found in TLs or carbon sources from summer to autumn. The primary carbon source for ice fauna was Ice-POM (mean 67%), although ice fauna with TL > 3 (adult Onisimus nanseni and juvenile polar cod) primarily utilized a pelagic food source.  相似文献   

舟山岩相潮间带动物群落结构的研究   总被引：4，自引：0，他引：4  

蔡如星  卢建平 《海洋学研究》1993,11(4):30-41

本文应用数理统计方法研究了舟山海区岩岸潮间带中26个测站的春季动物群落结构。根据26个站的位置分为近岸区、近外海区和外海区3个区域。各站均以软体动物和甲壳动物为群落主要组成成分,群落种类组成数从近岸到外海呈增长趋势,且优势种亦从低盐种类向高盐种类演替。近岸区群落主要优势种为短滨螺Littorina brevicula、粗糙滨螺L.scabra、僧帽牡蛎Ostrea cucullata、白脊藤壶Balanus albicostatus等;近外海区为短滨螺、粒结节滨螺Nodilittorinaexigua、僧帽牡蛎、鳞笠藤壶Tetraclita squamosa squamosa、白脊藤壶等;外海区为粒结节滨螺,疣荔枝螺Purpura clavigera、条纹隔贻贝Septifer virgatus、日本笠藤壶T.japonica及藻类等。但群落个体密度和生物量从近岸到外海呈减少趋势。从近岸到外海,群落的Shannon-Wiener多样性指数H和Pielou均匀度J均增加,而McNaughton优势度D减少。群落结构从近岸到外海渐趋复杂。但整体上,舟山海区岩岸春季动物群落结构是比较简单的(绝大多数断面H值小于2.50,J值小于0.5。而D值大于0.6)。近外海区的群落结构比较相似于外海区的群落。根据平均聚类分析,这26个群落可以分为三个生态类型,即隐蔽性岩岸群落,半隐蔽性岩岸群落及开敞性岩岸群落。  相似文献   

Development of Small Mytllus Beds and its Effects on Resident Intertidal Macro fauna     

Carmen-Pia  Günther 《Marine Ecology》1996,17(1-3):117-130

Abstract. The development of temporary Mytilus edulis beds and their associated macro fauna was studied on an intertidal sand flat in the German Wadden sea during 1986 by comparing mussel beds with bare sandy areas of the same tidal elevation. Macro fauna samples We taken with a 100 cm² corer (penetration depth 27 cm, mesh size 0.5 mm, 5 parallel samples).
Numbers of taxa and diversity were higher in the mussel beds compared to the sandy areas. The abundance of macro fauna organisms decreased with the age of the mussel bed, whereas the relative abundance of species was not strongly affected. Hydrobia ulvae , oligochaetes, and Heteromastus filiformis dominated the macro fauna inside as well as outside the mussel beds. Among the lower ranks of dominance changes in species composition were observed due to increasing densities of opportunistic polychaetes.
About six weeks after the establishment of the mussel beds a higher abundance of Capitella spp., Polydora ligni, Tharyx marioni , and nemerteans occurred within the mussel beds while other species such as Hydrobia ulvae and Pygospio elegans showed a significantly lower abundance compared to the adjacent flat. Macoma balthica as well as Mya arenaria were not affected by the alteration of a bare sand flat to a mussel bed. O-group Carcinus maenas reached their highest abundance in the mussel beds (over 1000 indiv. m^-2). In contrast juvenile Crangon crangon preferred the bare sand flat. After destruction of the mussel beds by an early autumn storm, species abundance and composition was similar to the situation before the mussel beds had become established.  相似文献   

Spatio-temporal variations in the diversity and abundance of commercially important Decapoda and Stomatopoda in subtropical Hong Kong waters     

Karen K.Y. Lui  Jasmine S.S. Ng  Kenneth M.Y. Leung   《Estuarine, Coastal and Shelf Science》2007,72(4):635-647

In subtropical Hong Kong, western waters (WW) are strongly influenced by the freshwater input from the Pearl River estuary, especially during summer monsoon, whereas eastern waters (EW) are predominantly influenced by oceanic currents throughout the year. Such hydrographical differences may lead to spatio-temporal differences in biodiversity of benthic communities. This study investigated the diversity and abundance of commercially important decapods and stomatopods in EW (i.e. Tolo Harbour and Channel) and WW (i.e. Tuen Mun and Lantau Island) of Hong Kong using monthly trawl surveys (August 2003–May 2005). In total, 22 decapod and nine stomatopod species were recorded. The penaeid Metapenaeopsis sp. and stomatopod Oratosquillina interrupta were the most abundant and dominant crustaceans in EW and WW, respectively. Both univariate and multivariate analyses showed that WW supported significantly higher abundance, biomass and diversity of crustaceans than EW, although there were significant between-site and within-site variations in community structure. Higher abundance and biomass of crustaceans were recorded in summer than winter. Such spatio-temporal variations could be explained by differences in the hydrography, environmental conditions and anthropogenic impacts between the two areas. Temporal patterns in the abundance–biomass comparison curves and negative W-statistics suggest that the communities have been highly disturbed in both areas, probably due to anthropogenic activities such as bottom trawling and marine pollution.  相似文献