我国海域常见有毒水母的分类检索   总被引：1，自引：0，他引：1       下载免费PDF全文

刘萍  张学雷  宋洪军  庞敏 《海洋科学进展》2013,31(2)

综合现有资料编制了我国海域常见的19种有毒水母种类的分类检索表.我国常见有毒水母分属于3纲8目14科17属,包括水螅水母类3种、管水母类2种、立方水母类2种、钵水母类12种,其中钵水母纲旗口水母目和根口水母目种类较多(各5种),其它目每目含1～2科且每科仅1属1种.对我国现有的水母分类体系中部分与国际通用体系不统一之处进行了厘正,如:火水母拉丁文种名应由Tamoya alata Uchida,1929厘正为Tamoya gargantua Haeckel,1880,建议将灯罩水母[Linuche draco (Haeckel,1880)]命名厘正为爪罩水母[Linuche unguiculata (Schwartz,1788)]等.  相似文献   

Significant population genetic structuring of the holoplanktic scyphozoan Pelagia noctiluca in the Atlantic Ocean     

《African Journal of Marine Science》2013,35(3):425-430

Pelagia noctiluca is thought to have a global distribution, yet our understanding of genetic connectivity across the range of this problem animal is poor. Here, we investigate the genetic structure of populations off southern Africa using mitochondrial COI and nuclear ITS1 and ITS2 genes, and compare the results to recent work conducted in the North-East Atlantic. Analyses showed significant differentiation between the southern and northern Atlantic population groups (COI Φ _st = 0.72, ITS2 Φ _st = 0.23, p < 0.001), which suggests historical rather than contemporary gene flow. Southern African samples showed high haplotypic (h = 1) and low nucleotide (π = 0.008) diversity, similar to those from Europe. Phylogenetic analyses suggest South African samples to have diverged earlier than those from the northern Atlantic.  相似文献   

Oil resources for the next century: What's ahead?     

N. Alazard  L. Montadert 《Natural Resources Research》1993,2(3):197-206

Proven reserves of liquid hydrocarbons are now assessed at between 950 and 1,000 billion barrels, depending on the source. Their life expectancy at the current rate of world production is about 41 to 45 years. This lifetime is much longer than what was predicted in both 1970 and 1980. However, this wealth of resources does not necessarily mean that the security of oil supplies is guaranteed for all countries. Oil reserves are unequally distributed from a geopolitical standpoint. Reserves and output are mainly due to big fields (with more than 500 million barrels of initial reserves).Though oil supplies seem to be ensured for the coming 30 to 40 years, what does the picture look like beyond 2020–20307 The increased lifetime of proven oil reserves has been apparent only in the last 10 to 20 years. The considerable increase in proven oil reserves reported after 1986 is, in fact, mainly due to revisions and extensions, rather than to new sources of oil: conventional oil (with the price per barrel of oil on the order of $20 and recovery rate around 30 percent) remaining to be discovered today; oil resources stemming from an improvement in recovery rate; oil resources resulting from exploitation of new zones, such as deep sea zones; and unconventional types of oil, such as extra-heavy crudes, tar sands, shale oils, and liquid hydrocarbons from chemical-enhanced oil recovery methods.  相似文献   

Not so rare Earth? New developments in understanding the origin of the Earth and Moon     

Kevin Righter 《Chemie der Erde / Geochemistry》2007,67(3):179-200

A widely accepted model for the origin of the Earth and Moon has been a somewhat specific giant impact scenario involving an impactor to proto-Earth mass ratio of 3:7, occurring 50-60 Ma after T₀, when the Earth was only half-accreted, with the majority of Earth's water then accreted after the main stage of growth, perhaps from comets. There have been many changes to this specific scenario, due to advances in isotopic and trace element geochemistry, more detailed, improved, and realistic giant impact and terrestrial planet accretion modeling, and consideration of terrestrial water sources other than high D/H comets. The current scenario is that the Earth accreted faster and differentiated quickly, the Moon-forming impact could have been mid- to late in the accretion process, and water may have been present during accretion. These new developments have broadened the range of conditions required to make an Earth-Moon system, and suggests there may be many new fruitful avenues of research. There are also some classic and unresolved problems such as the significance of the identical O isotopic composition of the Earth and Moon, the depletion of volatiles on the lunar mantle relative to Earth's, the relative contribution of the impactor and proto-Earth to the Moon's mass, and the timing of Earth's possible atmospheric loss relative to the giant impact.  相似文献   

中南半岛和西太平洋巨型成矿带Cu、Au矿化构造环境与成矿规律对比研究数据集          下载免费PDF全文

王功文  陈永清  黄静宁  刘胜前  吕秀美 《中国地质》2018,45(S1):85-98

“中南半岛和西太平洋巨型成矿带铜金矿化构造环境与成矿规律对比研究”以中南半岛与西太平洋巨型成矿带为研究区域,以铜、金为主要研究矿种,在前期1∶150万东南亚中南半岛和西太平洋巨型成矿带地质矿产图件编制的基础上,充分利用国际合作,系统开展资料收集,通过对老挝、泰国、缅甸、巴布亚新几内亚等国的研究区典型矿床成矿环境、控矿因素与成矿规律的研究,结合ETM+、Hyperion、ASTER多源遥感解译,深化了成果认知并出版了中英文图件;重点剖析了老挝Cu、Au矿床,在老挝阿文矿区开展了找矿示范和钻探验证并取得了很好的找矿效果;利用MapGIS、ArcGIS技术平台,编制成矿区带成矿规律图,建立不同矿种定量评价模型和东南亚重要成矿区带金铜矿床空间数据库;利用数学建模方法开展研究区的资源潜力评价,圈定老挝、缅甸、泰国、巴布亚新几内亚等研究区不同矿种成矿远景区。该数据集不仅是对已经取得的矿产资源区划和资源潜力评价工作的整理和总结,也为科学地引导国家地质“境外”找矿（“一带一路”倡议）部署工作提供理论基础。  相似文献   

Collapse of zooplankton stocks during Liriope tetraphylla (Hydromedusa) blooms and dense mucilaginous aggregations in a thermohaline stratified basin          下载免费PDF全文

Izzet Noyan Yilmaz 《Marine Ecology》2015,36(3):595-610

A growing number of studies report an increase in jellyfish populations worldwide that may have consequences for marine planktonic food web dynamics. The principal objective of this study was to understand the changes in a zooplankton community during blooms of Liriope tetraphylla and subsequent mucilage events in the Sea of Marmara, a small highly stratified transitional basin between the Black and Aegean Seas. Liriope blooms observed in 2006 and 2007 reached a maximum abundance of 2978 ind.·m^?3, following the species' first observation in 2005. Jellyfish species are known to play a key guild role by restructuring plankton communities and in the Sea of Marmara Liriope caused a temporal regime shift from a crustacean‐ to a jellyfish‐controlled system. A rapid decline in abundance of most important zooplankton species followed the Liriope increase, together with a drastic shift in community structure. The dominant summer–autumn species Penilia avirostris (Cladocera) vanished in the autumn of 2006 and was diminished ~30‐fold in 2007 when compared with years without Liriope. The decline in zooplankton and the devastating effects of mucilage on pelagic ecosystem and socio‐economics through restricting commercial fisheries implied sensitivity of the already perturbed Marmara ecosystem to changes in predator densities and environmental stability.  相似文献   

海蜇养殖港塭微型浮游动物的摄食和生产力研究     

张凯  田相利  董双林  冯建祥  孙侦龙  宫海宁 《中国海洋大学学报(自然科学版)》2011,41(4):61-68

通过对山东省靖海湾海蜇养殖港塭定期采样,采用稀释法研究该海蜇养殖港塭水体中浮游植物的生长率、微型浮游动物对浮游植物的摄食率、摄食压力以及微型浮游动物的生产力。研究结果表明,海蜇养殖港塭微型浮游动物组成比较简单,海蜇养殖期间微型浮游动物丰度低于海蜇捕捞结束期。其中,海蜇养殖期间微型浮游动物的优势种为根状拟铃虫(Tintinnopsis radix),为600~2 600 ind/L,而海蜇捕捞结束后优势种为根状拟铃虫、诺氏麻铃虫(Leprotintinnus nordquisti)和运动类铃虫(Codonellopsis mobilis),丰度分别为3 000~6 000、1 500~3 0001、500~3 000 ind/L。研究期间,该港塭浮游植物生长率为0.05~1.03 d-1。微型浮游动物的摄食率为0.24~2.37 d-1,对浮游植物现存量的摄食压力为21.10%~90.61%,对潜在初级生产力的摄食压力为77.08%~583.68%,而微型浮游动物的次级生产力占初级生产力的22.92%~76.92%。本研究表明微型浮游动物在海蜇养殖港塭生态系统物质和能量流动中起着重要作用。  相似文献   

2019年5月黄海及东海北部大型水母分布特征     

郭东杰  张芳  王朋鹏  吴强 《海洋与湖沼》2019,50(6):1292-1301

2019年5月,利用渔业底拖网,对我国黄海以及东海北部海域进行了全面系统的大型水母调查,分析了大型水母的种类组成、伞径大小和生物量以及与温度、盐度的关系。结果表明,本次调查主要捕获到沙海蛰、霞水母、洋须水母、多管水母四种大型水母,沙海蛰生物量最高,多管水母分布范围最广、数量最大。沙海蛰集中分布在调查海域南部,各海域伞径差异显著,在黄东海交界海域采集到幼水母体(10cm),生物量高值区出现在东海北部离岸海域,可达6422.16kg/km2;白色霞水母集中分布在东海北部,在近岸海域采集到幼水母体(6—7cm),生物量高值区位于离岸海域,可达7417.49kg/km2;洋须水母集中分布在黄海水深较深海域,北部海域个体较大,在黄海中部、南部交界处采集到幼水母体(10cm),生物量较低,高值区出现在黄海中部与南部,可达449.94kg/km2;多管水母分布范围较广,东海北部海域个体伞径较大,在山东半岛东部发现幼水母体(5cm),生物量高值区出现在黄海中部近岸海域,可达4901.42kg/km2。对比文献资料,发现整个调查海域,大型水母总体生物量比2015年同期有所增加。本文为研究该海域大型水母的年际变化规律提供数据基础。  相似文献   

秋季红沿河核电站海域水龄分布及其对水母丰度分布的影响     

邱敏志  苏薇  姚庆祯  王彦涛  张广跃  许博超  张晓洁 《海洋学报》2020,42(4):122-127

本研究调查了秋季红沿河核电站海域镭、氡同位素的活度水平及分布情况,结合镭同位素表观年龄模型计算该海域的水体年龄,进而得出研究区域的水体运移方向,初步探讨了水母丰度分布与水体运移的相关关系。得到结论如下:(1)红沿河核电站海域表层水体中224Ra、226Ra及222Rn的活度水平分别为2.9～62.4 dpm/(100 L),11.9～57.4 dpm/(100 L)及0.1～1.3 dpm/L,镭同位素活度呈现出近岸高、远岸低的分布趋势,氡同位素的分布则更大程度上受水温控制;(2)通过224Ra/226Ra表观年龄模型计算得出红沿河海域表层水体年龄范围介于0～16 d,平均年龄(10.9±3.6) d,水体主体流向为北偏东方向,流速为7.2 cm/s;(3)水母丰度分布与水体流向呈现出较为一致的对应关系,在主体流向方向上,水体年龄较大的海域水母丰度最高。  相似文献   

华北北部大型-超大型矿床的特征及其形成的宏观地质背景   总被引：2，自引：0，他引：2  

刘伟  邓军  储雪蕾  翟裕生  徐贵忠  李新俊 《地球物理学进展》2000,15(2):67-78

华北北部经历了太古宙－元三宙克拉通基底形成演化、中新元古宙裂谷作用、古生代“软”造山中生代伸展构造体制以及新生代盆－岭构造演化。中元古宙和中生代是华北北缘的两个大规模成矿时期华北中段从南往北依次公布关：华北克拉通北缘Ａｕ－Ｃｕ矿化集中区;大兴安岭Ｃｕ－Ｓｎ多金属矿化集中区;北邻蒙古和俄罗期境风Ｆｅ－Ａｕ－Ｕ－ＷＳｎ（Ｍｏ,Ｂｅ）集中分布。Ｍｏ矿化主要出现在克拉通内部,Ｓｎ矿化主要出现在大兴安岭地区  相似文献