In situ Bicarbonate Uptake by Bacteria-Alvinella Associations     

A. M. Alayse-Danet  F. Gaill  D. Desbruyeres 《Marine Ecology》1986,7(3):233-240

Abstract. Three species of Alvinellidae are found on walls of some hydrothermal chimneys at 13^o N on the East Pacific Rise (EPR); numerous epibiotic bacteria were associated with two of these polychaetes, Alvinella pompejana and Alvinella caudata , but not with the third, Paralvinella grasslei. Many studies suggest that chemoautotrophic bacteria play a prominent role in deep-sea hydrothermal vent ecosystems. Particularly important are the intracellular bacteria present in the giant pogonophores and bivalve molluscs.
The abundant epibioses observed on these Alvinella species are unusual and the relationships between these bacteria and the worms are unknown. Previous results, including ¹³C values, morphological insertion of the bacteria on the epidermis, presence of ribulose biphosphate carboxylase, and fixation of ¹⁴C bicarbonate in some bacteria and in the dorsal epidermis, suggest that a trophic relationship could exist between Alvinella and its epibiotic bacteria. The present study compared the incorporation area of ¹⁴C bicarbonate in the 3 species. Paralvinella , which is devoid of epibiotic bacteria, served as a control.  相似文献   

Life-history traits of the symbiotic scale-worm Branchipolynoe seepensis and its relationships with host mussels of the genus Bathymodiolus from hydrothermal vents     

Temir A. Britayev  Daniel Martin  Elena M. Krylova  Rudo von Cosel  & Tatiana S. Aksiuk 《Marine Ecology》2007,28(1):36-48

Associations between scale‐worms and giant mussels are common constituents of hydrothermal vent and cold seep ecosystems, but very little is known about their nature and ecology. Here, we analyze the ecological characteristics of the associations between Branchipolynoe seepensis, an obligate symbiotic polychaete, and their host mytilid mussels Bathymodiolus puteoserpentis and B. azoricus inhabiting hydrothermal vent fields on the Mid‐Atlantic Ridge. Infested mussels generally harbored a single symbiont (<4% had two to six worms). Infestation rate varied from 7.2% to 76.5%, increasing with mussel size, and was significantly lower for B. puteoserpentis. Symbiont density at Lucky Strike ranged between 1071 and 1191 individuals m⁻². Female symbiont size was always positively correlated with host size, while only males and juveniles from small mussels showed the same trend. This suggested a relatively long‐lasting host/symbiont association for females and short‐lasting association with successive reproductive migrations for adult males. The sex ratio of symbionts was always biased in favor of females. Males were smaller and more slender than females and had one mode in their size distributions, whereas females typically had three or more modes, suggestive of a longer life span in females. Between 59.1% and 72.2% of mussels had damaged soft tissues with substantially higher incidence of trauma in infested ones, suggesting that symbionts may cause trauma. The symbionts also induce tunnel‐like structures among the ctenidia, indicating fidelity to a particular location inside the host. Based on our data, together with the fact that infested mussels became relatively wider than non‐infested ones, this association is considered parasitic (likely kleptoparasitic). Our data, together with those from previous studies, allowed us to define the main life‐history traits of B. seepensis: (i) the relationship with their host is parasitic, (ii) the association begins at the smallest mytilid size classes, (iii) there is sexual dimorphism in body size, (iv) sex ratio deviates from 1:1 in favor of females, (v) fertilization occurs through temporal pairing and pseudocopulation, (vi) sperm are stored by females, (vii) eggs are large (likely lecithotrophic or with direct development), (viii) females have a longer life span than males, (ix) adult males may be semalparous, undertaking reproductive migrations followed by a short period of pairing and then death, and (x) females have a semi‐continuous iteroparous reproductive cycle.  相似文献   

九龙江口一岩心的重矿物组合     

洪辉亮  陈峰 《台湾海峡》2003,22(1):65-78

本文详细地分析了九龙江口SD0 3岩心中自生矿物的成因 ,推断河口区在约1 0ka ,B .P .中历经了河流沉积、湖泊沉积和河口海湾沉积三种沉积环境 .在沉积环境演化过程中共形成了 1 0种重矿物组合 .  相似文献   

北极圈海域表层沉积物的黏土矿物特征及其环境意义   总被引：2，自引：0，他引：2  

邱中炎  沈忠悦  韩喜球 《海洋地质与第四纪地质》2007,27(3):31-36

应用X射线衍射(XRD)分析技术对北极圈海域15个表层沉积物的黏土矿物进行了研究。结合伊利石的结晶度指数综合分析了研究区黏土矿物的组成和分布特征及其物质来源、沉积环境和水动力条件。结果表明,北极圈海域研究区的黏土矿物以伊利石为主(33%),其次为伊/蒙间层矿物(25%)、绿泥石(23%)、高岭石(15%)以及蒙皂石(4%)。伊利石的开形指数(Ns)都比较小,大多在1~2之间,Ns的分布对物源有一定的指示意义。楚科奇海区具较弱的水动力条件,沉积环境较稳定;白令海具强烈的水动力条件,属于冲刷环境。认为北极圈海域研究区的黏土沉积物均有三方面来源,即河流输入、海洋自生和冰筏搬运物。  相似文献   

冲绳海槽Jade热液区块状硫化物中流体包裹体的氦、氖、氩同位素组成   总被引：3，自引：1，他引：3       下载免费PDF全文

曾志刚  秦蕴珊  翟世奎 《海洋学报》2003,25(4):36-42

对冲绳海槽Jade热液区块状硫化物中流体包裹体的氦、氖和氩同位素组成进行了测定,流体包裹体的3He/4He比值为(6.2～10.1)Ra,均值为7.8Ra,与大洋中脊玄武岩一致[3He/4He≈(6～11)Ra],20Ne/22Ne比值为10.7～11.3,明显高于大气值(9.8),而40Ar/36Ar比值的变化范围在287～334之间,接近大气值(295.5),这些结果表明,块状硫化物中热液流体捕获的稀有气体是地幔和海水源组分混合的产物,且流体包裹体中的氦主要来自地幔,氖和氩主要来自海水。  相似文献   

Sulfur isotopic composition of modern seafloor hydrothermal sediment and its geological significance     

Zeng Zhigang  Li Jun  Jiang Fuqing  Qin Yunshan  Zhai Shikui 《海洋学报(英文版)》2002,21(4):519-528

ＩＮＴＲＯＤＵＣＴＩＯＮＤｕｒｉｎｇｔｈｅｐｅｒｉｏｄｏｆｅａｒｌｙ 1 980ｓｔｏｍｉｄ 1 990ｓ ,ｗｉｔｈｔｈｅｒａｐｉｄｄｅｖｅｌｏｐｍｅｎｔｏｆｅｘｐｌｏｒａｔｉｏｎｔｏｔｈｅｓｅａｆｌｏｏｒｈｙｄｒｏｔｈｅｒｍａｌａｃｔｉｖｉｔｉｅｓ ,ｔｈｅｓｕｌｆｕｒｉｓｏｔｏｐｉｃｃｏｍｐｏｓｉｔｉｏｎｏｆｈｙｄｒｏｔｈｅｒｍａｓｅｄｉｍｅｎｔｓａｒｏｕｎｄｔｈｅｗｏｒｌｄｈａｄｂｅｅｎｃａｒｒｉｅｄｏｕｔｔｏｓｏｍｅｅｘｔｅｎｔ (ＺｉｅｒｅｎｂｅｒｇａｎｄＳｈａｎｋｓ ,1 988;ＢｌｕｍａｎｄＰｕｃｈｅｌ…  相似文献   

冲绳海槽Jade热液区海底块状硫化物的Os同位素组成   总被引：5，自引：2，他引：5       下载免费PDF全文

曾志刚  翟世奎  杜安道 《海洋与湖沼》2003,34(4):407-413

用碱熔法新测得Jade热液区7件海底块状硫化物样品的锇含量及其同位素组成，^187Os／^186Os比值在2．205—6．462之间，均值为4．314，高于地幔端员，而低于海洋沉积物和海水端员，表明该区块状硫化物中锇是深部来源锇与海水和／或沉积物混合的产物。结合该区块状硫化物样品的REE、硫和铅同位素组成特征，进一步揭示出海水、长英质火山岩、沉积物和深部地幔源是形成Jade区块状硫化物的物源。  相似文献   

富Co铁锰结壳铂族元素与铼-锇同位素组成及其意义   总被引：13，自引：0，他引：13  

姚德  张丽洁  初凤友  杜安道  刘心中  杨富贵 《海洋地质与第四纪地质》2002,22(3):53-58

用ICP－MS测定了太平洋富Co铁锰结壳铂族元素和铼－锇同位素组成。富Co铁锰结壳不仅异常富集铂族元素，而且铂族元素及其它亲铁元素的配发与陨石特征非常相似。铁锰结壳的铼－锇同位素组成明显有别于大陆地壳岩石，和K－T界线沉积物相似，接近陨石值。世界大洋范围内的富Co铁锰结壳均产于远离海底构造热液活动区，几乎不可能受到地幔源热液作用的直接影响。因此，富Co铁锰结壳中的铂族元素可能部分来源于地外物质。  相似文献   

末次盛冰期以来冲绳海槽中段岩心中黏土粒级沉积物地球化学特征及物质来源的阶段性   总被引：4，自引：2，他引：4  

郭峰  杨作升  刘振夏  郭志刚  范德江  Saito Y  Berne S 《海洋学报》2001,23(3):117-126

测定了冲绳海槽DGKS9603孔21个样品中黏土粒级沉积物的常、微量元素组分,利用因子分析的方法,识别出对冲绳海槽中段沉积物物源有重要影响的陆源成因因子、生物成因因子及火山作用和海底热液因子.陆源成因因子的元素组合为Fe₂O₃,Al₂O₃,V等惰性元素及K₂O,MgO等氧化物;生源因子的元素组合为CaO,Sr,Ba,Mn,P;火山和海底热液成因因子的元素组合为Na,Co,Ni.据样品的因子得分将柱样由上而下划分出物源的4个不同阶段:A段生物成因因子得分高,沉积物质主要是本地生物沉积,但也有富含生物成因物质的陆源物质的贡献;B段火山作用所产生的沉积物质特征显著,Na,Co,Ni呈现高含量;C段以陆源物质和生源物质沉积混杂为特征,元素垂向上变化不大;D段主要为陆源物质,其他来源物质相对较少,且可能主要来自在末次冰期最盛期所出露的陆架沉积.提出了冲绳海槽物源具有阶段性的论点.由于末次盛冰期以来全球气候呈现冷暖交替的阶段性变化,本区物源的阶段性变化是这一时期气候和古环境阶段性变化的良好反映.  相似文献   

成都平原4 kaBP以来黏土矿物记录的古气候变化   总被引：3，自引：0，他引：3  

罗虹  朱利东  张擎  杨文光  阚瑷珂  向芳  罗丽萍  江章华  朱章义 《海洋地质与第四纪地质》2007,27(4):117-122

利用X射线衍射方法对成都金沙遗址IT6814探坑约4 m厚(约4 kaBP以来沉积)地层剖面的黏土矿物进行了分析,发现黏土矿物主要由伊利石、绿泥石、伊利石-蒙脱石混层矿物和少量高岭石组成。根据黏土矿物含量变化的分析和对比研究,划分出成都平原黏土矿物变化的5个阶段,得出成都平原的气候变化经历了由温凉偏干与温暖潮湿的交替,在2 500 aBP发生了较为明显的快速降温过程。通过对比探讨了古人类活动对黏土矿物的影响尺度,认为古人类活动的影响较低,黏土矿物的成分和含量可以作为气候变化的指示剂。  相似文献