Across shore variability and trophodynamic features of meiofauna in a microtidal beach of the NW Mediterranean   总被引：2，自引：0，他引：2  

M. Moreno  T.J. Ferrero  V. Granelli  V. Marin  G. Albertelli  M. Fabiano 《Estuarine, Coastal and Shelf Science》2006,66(3-4):357-367

The across shore variability and trophodynamics of meiofauna were studied in a microtidal beach of the Thyrrenian Sea (NW Mediterranean). Two sites were sampled at Collelungo beach (Maremma Park, Italy) subjected to different regimes of sediment erosion and deposition. At each site, four levels were sampled in November 2002 and May 2003 along a transect from the supralittoral zone to the surf zone. Sediment cores were taken down to a depth of 10 cm and meiofaunal abundance and community structure were analyzed and related to the principal trophic resources (quantity and quality of organic matter, chlorophyll a, bacteria density and biomass).Meiofaunal abundance ranged between 14 ind. 10 cm⁻² and 716 ind. 10 cm⁻² in the top 0–10 cm of sediment. Abundance was lower in the surface (0–2 cm) than in the deeper (5–10 cm) sediment layers but no significant differences were found between the two sites.Multivariate BIOENV analysis showed that dryness, grain size (related to physical processes) and bacterial biomass, were the main variables explaining meiofauna distribution in these beaches. Meiofaunal densities and number of taxa were always higher at the swash level, while lower abundances were observed at the dry sampling level (+5 m). This across shore trend was also observed for the quality of the organic matter (PRT/CHO) and bacterial densities. Nematode assemblage structure at the swash sampling level showed a dominance of non-selective deposit feeders (1B), with Xyalidae as the dominant family (56%), followed by Thoracostomopsidae (14%) and Selachnematidae (12%).According to the findings, physical and biological variables at the swash level create optimal living conditions for the meiobenthos, making the swash a key area within the beach ecosystem, with potential implications within basic and applied ecological studies.  相似文献   

海绵共栖细菌抗菌活性及其群体感应信号的研究     

郭秀春  郑立  崔志松  杨佰娟  田黎  王小如 《海洋学报》2010,32(5):135-143

利用平板涂布法从南海海绵生物样品中分离海绵共栖细菌,以枯草芽孢杆菌、金黄色葡萄球菌、大肠杆菌及酿酒酵母作为实验用指示菌对海绵共栖细菌进行了抗菌活性筛选。利用气相质谱联用仪(GC-MS)建立了群体感应信号分子酰基高丝氨酸内酯类化合物(AHLs)的检测方法,分析了活性菌株粗提液中信号分子的产生及种类。同时采用16S rDNA同源性和系统发育分析对活性菌株进行种属鉴定和系统发生学研究。结果表明,在分离到的94株海绵共栖细菌中18株(占19.1%)细菌具有抗菌活性。通过GC-MS检测确定大多数活性菌株都含有AHLs,因此提出了海绵共栖细菌抗菌活性与群体感应之间可能存在必然联系的推测。通过细菌分类鉴定,结果显示具有抗菌活性的细菌大部分属于芽孢杆菌属(Bacillus)。  相似文献   

Characterisation of Heterotrophic Microorganisms Isolated form the "Grotta Azzura" of Cape Palinuro (Salerno, Italy)     

Francesco Canganella  Giovanna Bianconi  Agata Gambacorta  Chiaki Kato  Katsuyuki Uematsu 《Marine Ecology》2002,23(S1):1-10

Abstract. Hydrothermal vent ecosystems have been extensively investigated during the last 20 years; shallow water hot springs (typically found below 50 m depth) have also been studied, and from these ecosystems many thermophilic and hyperthermophilic organisms were isolated and described.
The submarine caves of Cape Palinuro were discovered long ago, but only during the last decades were geological and biological investigations carried out, yielding a large number of reports on this fascinating environment. During the last two years, several samples of water, mud, and/or bacterial mat were collected within the "Grotta Azzurra", and enrichment experiments were performed using peptone, starch, glucose or pullulan as main organic nutrients. Many heterotrophic strains were isolated and most of them grew optimally between 37 and 43 ° C with the addition of 0-2 % NaCl. Growth was usually observed between 10 and 50 ° C the range of growth pH was 4 to 9, and NaCl concentrations up to 10–12 % were tolerated in most cases.
The analysis of 16S rDNA performed with the most representative isolates showed a close phylogenetic relationship with the genera Bacillus, Vibrio, Citrobacter and Escherichia. Moreover, an isolate showing morphological and physiological similarities with the genus Enterococcus was characterised and taxonomically described based on the 16S rDNA sequence.  相似文献   

中国天竺鲷属鱼类的矢耳石形态特征   总被引：2，自引：0，他引：2  

叶振江  张弛  王英俊  李震华 《海洋学报》2010,32(5):87-92

利用采自我国近海的105尾标本,分析了细条天竺鲷、宽条天竺鲷、黑鳃天竺鲷、黑边天竺鲷、垂带天竺鲷、四线天竺鲷、半线天竺鲷、斑鳍天竺鲷等8种天竺鲷属鱼类的矢耳石形态特征。8种鱼类矢耳石前部均较尖,后部略圆钝,背部呈折线状,腹部呈圆弧形,背部中央有缺刻,听沟宽阔;8种鱼耳石长宽比的比值为1.35～1.63,矩形趋近率为0.67～0.77,充实度为14.77～24.99。以上述三种形态学参数为基础进行聚类分析,可将8种鱼类分为3组:细条天竺鲷、宽条天竺鲷、黑边天竺鲷、黑鳃天竺鲷为一组;垂带天竺鲷、四线天竺鲷、半线天竺鲷为一组;斑鳍天竺鲷为一组。耳石听沟边缘走向、宽度以及耳石外部边缘光滑度等轮廓特征在8种天竺鲷属鱼类间呈显著的种间差异。以这些形态特征为基础,编制了8种天竺鲷属鱼类的检索表,检索表表现的种间分类关系特征与聚类分析结果基本一致。  相似文献   

渤海中部海线虫属(线虫纲:嘴刺线虫目,烙线虫科)一新种(英文)     

张志南 《中国海洋大学学报(自然科学版)》1990,(3)

记述了渤海中部在站位DA18、水深27m采到的海洋线虫一新种,渤海海线虫Thalassironus bohaiensis sp nov该新种的个体大小和De Man比值(a.b.c)与Thalassiro-nus bipartitus(Wieser,1953)十分相似,但雄性副交接刺的结构,两种有显著的差异。新种的副交接刺末端钝且内凹,在腹侧近末端有一明显的小突起,而相近种的副交接刺末端尖锐,没有任何突起。此外,新种雄性交接刺长度也与相近种有明显的差别(62—67μmvs 52μm)列表比较了新种与相近种以及该属目前已报导的其他三个种的详细形态学特征。模式标本保存在青岛海洋大学海洋生物系。  相似文献   

ON THE MARINE CILIATE, Pseudocohnilembus hargisi(PROTOZOA, CILIOPHORA, SCUTICOCILIATIDA) WITH COMPARISON OF ITS RELATED SPECIES     

龚骏  马宏伟  宋微波 《中国海洋湖沼学报》2002,(3)

ＩＮＴＲＯＤＵＣＴＩＯＮＳｃｕｔｉｃｏｃｉｌｉａｔｅｓｈａｖｅｌｏｎｇｂｅｅｎｋｎｏｗｎｔｏｂｅｆｏｕｎｄｉｎｇｒｅａｔａｂｕｎｄａｎｃｅｉｎａｌｌｋｉｎｄｓｏｆｈａｂｉｔａｔｓ,ａｎｄｈａｖｅｇｒｅａｔｄｉｖｅｒｓｉｔｙｉｎｓｐｅｃｉｅｓｎｕｍｂｅｒ,ｓｔｒｕｃｔｕｒｅ ,ｂｅｈａｖｉｏｒａｎｄｏｔｈｅｒｂｉｏｌｏｇｉｃａｌｃｈａｒａｃｔｅｒｓ.Ａｓａｃｏｍｍｏｎｌｙ ｆｏｕｎｄｔａｘｏｎｆｒｏｍｃｏａｓｔａｌｗａｔｅｒａｎｄｃｕｌｔｕｒｅｂｉｏｔｏｐｅｓ,Ｐｓｅｕｄｏｃｏｈｎｉｌｅｍｂｕｓｈａｒｇ…  相似文献   

福建省土壤分类参比与土壤系统分类检索   总被引：6，自引：0，他引：6  

陈健飞 《地球信息科学学报》2002,4(1):66-70

在阐述不同土壤分类系统参比规则和方法的基础上 ,根据长期研究工作积累 ,对福建省的主要土壤类型进行发生学分类与中国土壤系统分类 (修订方案 )的参比 ,初拟了福建省土壤系统分类检索表 ,以推动区域土壤分类的变革 ,方便本领域的学术交流和技术引进.  相似文献   

Use of discriminant analysis for classification of strata in sedimentary successions     

Douglas M. Hawkins  Stephen E. Rasmussen 《Mathematical Geology》1973,5(2):163-177

The technique of instrumental neutron activation analysis (INAA) has been used to analyze chip samples of geological material for 12 elements. Discriminant analysis has been used to classify the unknown chip samples to the correct stratum in a sedimentary succession.  相似文献   

Lake Tahoe vs. Lake Kinneret phytoplankton: comparison of long-term taxonomic size structure consistency     

Yury Kamenir  Monika Winder  Zvy Dubinsky  Tamar Zohary  Geoff Schladow 《Aquatic Sciences - Research Across Boundaries》2008,70(2):195-203

  相似文献   

Study of time-related variability within the genusAstarte (bivalvia): A multivariate approach     

F. Symons  A. Ringele 《Mathematical Geology》1976,8(2):113-136

A morphometric analysis of two closely related species Astarte omaliiand Astarte basterotiwas made. Specimens were sampled from three successive stratigraphic levels of the Pliocene deposits of northern Belgium. Two chronological subspecies were distinguished—Astarte omalii omaliiand Astarte omalii basteroti.  相似文献