Modern Dinoflagellate Cysts Distribution off the Eastern Part of Geoje Island,Korea     

Hyeon Ho Shin  Yang Ho Yoon  Kazumi Matsuoka 《Ocean Science Journal》2007,42(1):31-39

Distributional characteristics of dinoflagellate cysts in surface sediments were investigated in relation to environmental factors in the eastern part of Geoje Island, Korea. Samples were collected from 10 stations in February of 2004 and water temperature and salinity were measured in February, May, September and November of 2004. Total 30 taxa of dinoflagellate cysts were identified representing 19 genera, 28 species and 2 unidentified species. Among these dinoflagellate cysts,Brigantedinium spp. of which relative proportion in the total dinoflagellate cysts was 23.5%, was the most abundant at all stations except St. 1, and was followed bySpiniferites bulloideus (8.6%),Lingulodinium machaerophorum (8.2%) andDiplopsalis lenticula (6.7%). In addition, ellipsoidal cysts of the genusAlexandrium (Alexandrium catenella - tamarense type) andGymnodinium catenatum, known to be causative organisms for PSP, occurred with high concentrations.Scrippsiella trochoidea was also found; however, its cyst concentration was low. Generally, species composition in the study area was similar to these reported from Jinhae Bay and Busan Harbor and several dinoflagellate cysts reflected the eutrophic condition. Cyst distribution in the eastern part of Geoje Island seems to be influenced by the Tsushima Warm Current flowing from the southwest. The mean water temperature was 12.0°C in February, 14.7°C in May, 20.9°C in September and 17.2°C in November, which was most favorable forAlexandrium spp. growth. The abundances of dinoflagellate cysts ranged from 528 to 2,834 cysts/g dry sediment. Higher concentrations were recognized in sediments of west area of the Jisimdo than at other stations. The cyst composition of this area was closely related to these of Jinhae Bay and Busan Harbor from which currents flow into this area. Higher cyst concentration in the west area of Jisimdo might be due to formation of the gyre.  相似文献   

一种快速制备甲藻细胞PCR扩增DNA模板的方法     

张炎  韩笑天  邹景忠  周名江  王广策 《海洋科学》2005,29(11):1-3

报道了一种快速制备PCR扩增甲藻细胞模板DNA的方法。以赤潮甲藻塔玛亚历山大藻（Alexandrium tamarense）和链状亚历山大藻（Acatenella）为目标藻，对藻液预处理后直接用于PCR扩增，获得5,8S核糖体RNA基因及其两侧的核糖体RNA基因转录单元内基因间隔区（internal transcribed spacer，ITS）序列片段，成功测序。此方法避免了复杂的DNA提取过程。  相似文献   

Resting cells of microorganisms in the 20–100 μm fraction of marine sediments in an Antarctic coastal area     

Mutsuo Ichinomiya  Miwa Nakamachi  Mitsuo Fukuchi  Akira Taniguchi 《Polar Science》2008,2(1):27-32

We investigated the morphological features, vertical sinking fluxes, and number densities of the resting cells of ice-associated microorganisms in the 20–100 μm fraction of natural marine sediments collected from ice-covered and ice-free areas around Syowa Station, Lützow-Holm Bay, East Antarctica. We identified the resting cells of various taxonomic groups, including the spores of a diatom, cysts of three dinoflagellates, cysts of five oligotrich ciliates, and the eggs of a mesozooplankton. This is the first report of oligotrich ciliate cysts from Antarctic waters. The resting spores of Thalassiosira australis (diatom), cysts of Polarella glacialis (dinoflagellate), and egg type 1 sink to the bottom sediment during summer. Our results suggest that some planktonic and ice-associated microorganisms in Antarctic coastal areas send their resting cells to the bottom sediments as seed populations for the following generation.  相似文献   

Disentangling late-Holocene climate and land use impacts on an Austrian alpine lake using seasonal temperature anomalies,ice-cover,sedimentology, and pollen tracers   总被引：1，自引：0，他引：1  

Roland Schmidt  Monika Roth  Richard Tessadri  Kaarina Weckström 《Journal of Paleolimnology》2008,40(1):453-469

Major and trace elements, minerals and grain-size were analysed from a sediment core covering the last 4,000 years of an Austrian Alpine lake (Oberer Landschitzsee, ObLAN, 2,076 m a.s.l.). These analyses were combined with autumn and spring temperature anomalies and ice-cover estimated from a diatom and chrysophyte cyst, thermistor-based regional calibration dataset and selected pollen markers published previously. Diatom-inferred pH (Di-pH) and DOC (Di-DOC) completed the multi-proxy approach, which, together with ordination techniques (PCA and RDA), helped (1) to confirm proposed climatic patterns and hypotheses, and (2) to disentangle the complex interactions between climatic and anthropogenic impacts. Shifts in chemical and physical weathering, erosion, production, lake stratification, redox potentials and air pollution were the major processes that have affected Oberer Landschitzsee in relation to climate, lake/catchment interactions, and human impact. Geochemistry supported the finding that the four waves of high-altitude land use (Early to Middle Bronze, ca. 1,800–1,300 B.C.; Late Bronze to Hallstatt, ca. 1,000–500 B.C.; Celtic to Roman, ca. 300 B.C.–400 A.D.; and Medieval, ca. 1,000–1,600 A.D.) were coupled mainly with warm periods. Increased production, onset of lake stratification, and the deterioration of hypolimnetic oxygen conditions were the major changes governing in-lake processes during climate warming. They resulted in specific element assemblages associated with organic matter accumulation (Br), oxygen depletion (As, Ga, Cu, S), and changes in redox (Fe/Mn). The Se/Di-DOC ratio was introduced to track shifts between in-lake production and allochthonous sources. Nutrient loading from pastures, coupled with climate warming, could explain that in-lake production was highest during Roman and Medieval land use. Lithogenic elements mainly originated from chemical weathering of silicate bedrock and they increased when intense land-use was coupled with climate deterioration and/or increased humidity. These perturbations were highest during a High Medieval climate fluctuation around 1,000 A.D. The association of sand with LOI and C/N and the decoupling of sand from quartz and feldspar separates erosion from physical weathering. Di-DOC, S, and C/N showed hybrid characters in relation to climate and human impact. The mineral proportions indicated gradients in relation to weathering, snow-cover and running waters, as well as vegetation. Air pollution by metallurgic industries, starting during the High Medieval and culminating during the Late Medieval, caused lead accumulation and could have contributed to As and S enrichment. Corresponding features in the distribution of selected elements and pollen tracers, as well as changes in mineral proportions, supported the hypotheses of shifts in seasonal climate and an overall trend towards more continental climate conditions since Medieval times.  相似文献   

Late Cretaceous palynology and paleoclimate change:Evidence from the SK1(South) core,Songliao Basin,NE China   总被引：1，自引：0，他引：1  

ZHAO Jing  WAN XiaoQiao  XI DangPeng  JING Xia  LI Wei  HUANG QingHua  ZHANG JinYan 《中国科学:地球科学(英文版)》2014,(12)

Cretaceous climate was warmer than today.The Songliao Basin contains one of the most important Late Cretaceous non-marine deposits in China for the research of the paleoenvironment and paleoclimate.This research is based on core samples from the SK1(S)borehole.The strata sampled are the upper part of the Quantou Formation to member 2 of the Nenjiang Formation,where spores,pollen,dinoflagellates,and other microfossils are abundantly preserved.Based on analysis of the spores and pollen fossils from the core samples,the following six fossil assemblage zones have been recognized in ascending order:The Cicatricosisporites-Cyathidites-Pinuspollenites,Schizaeoisporites-Cyathidites-Classopollis,Cyathidites-Schizaeoisporites,Schizaeoisporites-Cyathidites-Proteacidites,Proteacidites-Cyathidites-Dictyotriletes,and the Lythraites-Callistipollenites-Schizaeoisporites zones.The six fossil zones range from the late Cenomanian to early Campanian.The Late Cretaceous dinoflagellate cysts in the Songliao Basin are of high abundance and low diversity.Specific phytoplankton types reflect salinity changes of the Songliao Lake.Paleoecology of the dinoflagellates suggests that sediments of members 2 and 3 of the Yaojia Formation(K2y2+3)were deposited in a freshwater environment,whereas members 2 and 3 of the Qingshankou Formation(K2q2+3)and members 1 and 2 of the Nenjiang Formation(K2n1+2)were deposited in freshwater to brackish water environments.Combined with the paleoecology of dinoflagellates and the palynomorph biozones,valuable information of the paleoclimate was provided.The quantitative analyses of spores and pollen fossils,such as vegetation type,climate type,and humidity type,diversity and dominance,indicate a relatively sub-humid,mid-subtropical paleoclimate,with slight climatic fluctuation and/or temporal change.  相似文献   

Temporal population dynamics of dinoflagellate Prorocentrum minimum in a semi-enclosed mariculture pond and its relationship to environmental factors and protozoan grazers     

许恒龙  MIN Gi-Sik  CHOI Joong-Ki  朱明壮  姜勇  AL-RASHEID Khaled A.S. 《中国海洋湖沼学报》2010,(1)

The ecological processes and interrelationships between protists,either autotrophic or heterotrophic,and environmental factors in mariculture ponds are largely unknown.This study investigated the temporal dynamics of potentially harmful dinoflagellate,Prorocentrum minimum (Pavillard) Schiller,and its relationship to physico-chemical factors and protozoan grazers over a complete cycle in a semi-enclosed shrimp-farming pond near Qingdao,Northern China.P.minimum occurred frequently in low numbers from June to ...  相似文献   

1998年春季珠江口海域大规模赤潮原因生物的形态分类和生物学特征I   总被引：9，自引：4，他引：5  

黄长江  董巧香 《海洋与湖沼》2000,31(2):197-204

对１９９８年４月１５日采集于广东珠江口万山群岛桂山岛网箱养殖区的赤潮活体水样 和福尔马林固定样品进行优势种的形态分类和生物学特征的研究。结果发现,三宅裸甲藻 （Ｇｙｍｎｏｄｉｎｉｕｍ ｍｉｋｉｍｏｔｏｉ）是此次赤潮的最优势种,最高密度达到 ７．６ × １０６ｃｅｌｌｓ／Ｌ。另两种优 势种为斯氏多沟藻（Ｐｏｌｙｋｒｉｋｏｓ　ｓｃｈｗａｒｔｚｉｉ）和螺旋螺沟藻（Ｇｙｒｏｄｉｎｉｕｍ ｓｐｉｒａｌｅ）,其最高密度分 别达到 １．１× １０５ｃｅｌｌｓ／Ｌ和 １０４－１０５ｃｅｌｌｓ／Ｌ。此次赤潮的原因生物都属于裸甲藻类,死后或用 福尔马林固定后细胞要么立即裂解,要么变形缩小。有些种类如螺旋螺沟藻在固定样品中找 不到其踪迹,因而无法精确计数。本文描述的３种赤潮藻在细胞、色素体、核、上锥沟和链状群 体等形态构造及外观上与国外学者所描述的几乎完全一致,只是细胞比日本海域产的稍小。 这可能与珠江口海域纬度较日本低有关。电镜照片显示三宅裸甲藻有一明显的上锥沟,斯氏 多沟藻则营养细胞和孢囊同时存在。  相似文献   

从水动力学角度探讨沟鞭藻孢囊形态对沉积环境的适应     

杨宝兰 《现代地质》1997,11(2):145-148

摘 要　 从水动力学角度出发‚以孢囊沉降速率和孢囊强度两个概念为研究基点‚半定量化 地探讨了孢囊形态对沉积环境的趋同适应‚得出在低纬区的孢囊或远岸区的孢囊个体大、壁 薄、刺发育、长或多次分叉并结合成网络状;在高纬区或近岸区发育个体小、壁厚、刺不发 育的孢囊。  相似文献   

Multivariate analysis for ordination and comparison of size of Artemia cysts     

Tang Senming 《海洋学报(英文版)》1998,17(4):537-544

ThisresearchwasfundedbyNaturalScienceFoundationofFujianProvince.INTRODUCTloNBrineshrimpsaredistrbutedwidelyintheworld.Morethan35ohabitatshavebeenidenti-fiedsofar(VanhaeckeandSorgeloos,198O).Longadaptationtothenarrowbiotopscharacter-izedbyhighsalinityofsaltlakes,lagoonsandsaltfarms,thestrainhasdevelopedinherentcharac-terssuchascystsize,growthrateandtoleranttothehightemperature,etc.Thereforethecystbiometricshasoftenbeenusedinthespeciesidentification,asitisalsoeasyfordatagatheringwhencarr…  相似文献   

中国两性生殖卤虫卵及无节幼体的数值分类   总被引：1，自引：0，他引：1  

周可新  许木启  管越强  印象初 《湖泊科学》2003,15(2):153-159

本文用数值分类的方法对来自我国山西、内蒙古以及青藏高原的共15个两性生殖卤虫品系的卵、无节幼体进行了研究．通过卵和无节幼体的聚类分析,青藏高原卤虫品系和其它品系得到很好的分离．发现青藏高原卤虫品系的卵有三个特征,即卵径大,卵壳厚,卵呈紫红色,这些特征均是对那里高寒环境的适应．研究表明,随着分布区海拔的升高,中国各卤虫品系的卵和无节幼体有增大的趋势．其中西藏拉果错卤虫的卵和无节幼体是世界上所有已知品系中最大的．  相似文献