雷州马尾藻Sargassum leizhouense(Fucales,Phaeophyta)形态结构及分类研究   总被引：1，自引：0，他引：1  

赵素芬  孙会强  刘东超 《海洋与湖沼》2014,45(2):291-298

本研究通过对产于雷州半岛的雷州马尾藻(Sargassum leizhouense)形态结构进行研究,结合形态解剖、分类学特征等观察,比较了与同类组中其他3种马尾藻的特征差异,澄清了其分类地位,并修改了雷州马尾藻的检索表。结果表明,雷州马尾藻属于马尾藻属、真马尾藻亚属、叶托混生组、拟叶托混生亚组;尽管雷州马尾藻与该组的瓦氏马尾藻(S.vachellianum)、鳞茎马尾藻(S.bulbiferum)及滑托组的亨氏马尾藻(S.henslowianum)形态有许多相似之处,但其与上述3种马尾藻的主要差异在于球芽及分裂叶的有无。本研究不仅修改了雷州马尾藻分类地位,也为将来开展该马尾藻的人工繁育及养殖、加工提供帮助。  相似文献   

烟煤的宏观煤岩分类系统研究     

张群  潘治贵 《煤田地质与勘探》1999,27(2):2-5

烟煤的宏观煤岩分类是煤岩学研究的内容之一。本文建立了烟煤按煤岩成分-宏观煤岩类型进行两级划分的宏观煤岩分类系统,提出了划分宏观煤岩类型的定性和定量指标,制定了宏观煤岩类型的分类方案,规定了描述方法、内容和要求。   相似文献   

浙江6个列岛大型底栖藻类分类多样性   总被引：1，自引：0，他引：1  

求锦津  水柏年  水玉跃  张春草  董静瑞  李超男  孙鹏  张苗苗  田阔 《海洋与湖沼》2017,48(5):1004-1013

本文基于对七星列岛大型底栖藻类的实地调查,结合浙南3个列岛(七星列岛、南麂列岛和洞头列岛)和浙北3个列岛(渔山列岛、中街山列岛和马鞍列岛)大型底栖藻类物种组成的有关文献,构建大型底栖藻类基础数据库。采用平均分类差异指数△~+、分类差异变异指数∧~+、G-F多样性测度指数和相似性系数开展分类多样性研究。结果显示:6个列岛藻类在目级和科级的相似性很高,其值均在0.800以上;洞头列岛的△~+值最高(77.42),中街山列岛最低(72.65),这表明洞头列岛大型底栖藻类类群间的亲缘关系较远,中街山列岛藻类类群间的亲缘关系较近;七星列岛的∧~+值最高,达942.00,南麂列岛最低,仅865.12,这表明南麂列岛大型底栖藻类在不同分类阶元分布最均匀,七星列岛的藻类分布较集中;南麂列岛无论是F指数、G指数还是G-F指数的值均比其他5个列岛高,依次为18.62,4.40和0.76,这说明南麂列岛藻类的生态位分化程度较高。本研究构建了6个列岛大型底栖藻类资源与分类多样性基础数据库,为有效保护和管理大型底栖藻类提供了理论依据。  相似文献   

科尔沁沙质草地优势多年生植物氮素回收效率的分异特征   总被引：1，自引：0，他引：1  

李玉霖  崔夺  陈静  毛伟  赵学勇 《中国沙漠》2013,33(3):688-695

养分回收是多年生植物重要的适应策略,通过这种方式可以使植物重新利用体内养分。尤其在养分贫瘠的环境中,养分条件的微小变化都会影响植物的生长、竞争和适合度。但是,不同物种和不同生活型植物的氮素回收效率具有较高的变异,这对理解不同物种或生活型植物在生态系统功能中的作用具有重要意义。本研究分析了科尔沁沙质草地生态系统中39种多年生植物成熟绿叶和枯叶的氮素含量和氮素回收效率,以揭示不同物种或生活型植物氮素回收效率的分异特征。结果表明：科尔沁沙质草地优势多年生植物成熟绿叶氮素含量的变化范围在12.2～33.4 mg·g-1,平均值为23.3 mg·g-1;与全国及全球尺度上的研究结果相比,科尔沁沙质草地成熟绿叶氮含量平均值偏高,说明干旱荒漠环境植物叶片平均氮含量相对较高;多年生植物枯叶的氮素含量明显小于成熟绿叶氮素含量,变化范围在6.2～18.8 mg·g-1,平均值为11.3 mg·g-1;多年生植物氮素回收效率的范围在29%至74%之间变化,平均值为50.3%。这说明氮素回收是科尔沁沙质草地生态系统多年生植物重要的养分保留策略之一。另外,沙质草地不同生活型植物的氮素回收效率存在显著的差异。固氮植物和禾本科植物的氮素回收效率显著低于灌木和杂类草植物。这一结果间接说明植物氮素保持能力的分异是半干旱沙质草地植物共存的机理之一。  相似文献   

A comparative study of fish community in four main estuaries of China southeastern coastal areas and their adjacent waters   总被引：1，自引：0，他引：1  

Liangmin Huang  Yazhi Zhang  Xianshi Jin  Xiujuan Shan 《中国海洋大学学报(英文版)》2010,9(2):169-177

Based on literature and survery data of fish composition collected by bottom trawl investigation from 2006 to 2007 infour main estuaries of China southeastern coastal areas and their adjacent waters,changes of the taxonomic diversity across spatialand temporal scales of fish community were analyzed by taxonomic diversity indices.The results are as follows:a total number of1397 fish species(including some freshwater species),belonging to 2 classes,42 orders,186 families and 593 genera,were collected inthe studied sea areas.The species richness increased with lower latitudes,particularly so with Perciformes.There were 339 fish spe-cies in the Yangtze River Estuary and adjacent waters,belonging to 2 classes,31 orders,101 families and 231 genera.There were 535fish species in the Minjiang River Estuary and adjacent waters,belonging to 2 classes,33 orders,133 families and 323 genera.A totalnumber of 803 fish species were collected in the Jiulongjiang River Estuary and adjacent waters,which belonged to 2 classes,35 orders,155 families and 419 genera.And 1021 fish species which belonged to 2 classes,32 orders,153 families,and 466 genera were collectedin the Pearl River Estuary and adjacent waters.The numbers of orders and families of fish species from the northern to the southern wa-ters first increased and then decreased.The average variation in taxonomic distinctness(Λ+)gradually decreased with lower latitudes inthe four estuaries and adjacent waters.There were no significant differences in the average taxonomic distinctness(△+)among the fourestuaries and adjacent waters,and fish fauna were closely related with each other,and all of them belonged to the same zoogeographicalfauna(Indian-Malaysia fauna).Fish composition in the Minjiang River Estuary and adjacent waters was more similar to that in the Jiu-longjiang River Estuary and adjacent waters among the four estuaries.Compared with the historical data,the average taxonomic dis-tinctness of fish community showed a great decrease in the Minjiang River Estuary and the Jiulongjiang River Estuary and their adjacentwaters.  相似文献   

Symbiodinium (internal transcribed spacer 2) diversity in the coral host Agaricia lamarcki (Cnidaria: Scleractinia) between shallow and mesophotic reefs in the Northern Caribbean (20–70 m)          下载免费PDF全文

Matthew Q. Lucas  Michael Stat  Matthew C. Smith  Ernesto Weil  Nikolaos V. Schizas 《Marine Ecology》2016,37(5):1079-1087

This study investigated differences in Symbiodinium diversity in the scleractinian coral species Agaricia lamarcki between shallow (20–25 m) and mesophotic (50–70 m) depths in the Northern Caribbean. Corals were sampled in each of four shallow sites (20–25 m; n = 18) and three mesophotic sites (50–70 m; n = 18) from Mona Island (Puerto Rico) and the US Virgin Islands during a mesophotic exploratory cruise and from the La Parguera shelf edge, off Southwestern Puerto Rico. Symbiodinium diversity was assessed using internal transcribed spacer 2 sequences clustered into operational taxonomic units (OTUs). Clustering resulted in eight clade C OTUs and one clade D OTU. Of these, there were three common Symbiodinium OTUs consisting of C3 and D1a.N14 in shallow reefs and C11.N4 in mesophotic reefs. Statistical tests (permutational multivariate analysis of variance and analysis of similarity) showed significant differences between clade C Symbiodinium OTUs in A. lamarcki colonies located at shallow and mesophotic depths, indicating symbiont zonation. Symbiodinium diversity in A. lamarcki from the Northern Caribbean is comparable to previous reports in the Southern Caribbean for this species. This is the first report of the thermal tolerant species Symbiodinium trenchii (D1a) in A. lamarcki.  相似文献   

Macrobenthos of Kakinada Bay in the Godavari delta, East coast of India: comparing decadal changes   总被引：3，自引：0，他引：3  

Dipti Raut  T. Ganesh  N.V.S.S. Murty  A.V. Raman   《Estuarine, Coastal and Shelf Science》2005,62(4):609-620

A one-year study (1995–1996) on the macrobenthos over a spread of (37) hydrographically differing GPS-fixed sites in Kakinada Bay (mean salinity 27.16±0.4) and adjacent mangrove channels (14.78±0.55) in the Godavari delta, one of India's largest estuarine systems, revealed a great preponderance of benthic life. There were 11 diverse taxa represented by 95 species collected through several (303) grab and dredge hauls. Based on Bray-Curtis similarity through hierarchical clustering implemented in PRIMER, it was possible to distinguish the benthos into four assemblages each of which represented sites in the Central and North bay (Paphia textrix – Typhlocarcinus sp. Assemblage), South-East bay (Protankyra similis – Paphia malabarica Assemblage), Mangrove Outlets (Cerithidea cingulata Assemblage) and Mangrove channels (Diopatra neapolitana Assemblage). Benthos densities (mean nos. dredge haul⁻¹) were highest (299 individuals) at sites close to mangrove outlets. Species diversity (Margalef, d; Shannon-Wiener, H′) was low in general (d 1.244 to 2.251 and H′ 0.038 to 1.502). Sediments were mostly clayey-silt in nature except in southeast bay where they are silt-sand. Organic matter (mean) was at or near 1.3%. The observations have revealed marked changes in benthic community structure relative to an earlier investigation held in 1958–1963 in this area. Over the years, species such as Turritella duplicata, Tonna dolium and Placuna placenta found in considerable numbers previously have dwindled. Anomia, Bursa and Atrina and echinoderms, Astropecten indica, Echinodiscus auritus and Temnopleurus toreumaticus and the brachiopod, Lingula sp. of common occurrence in early 60s are absent altogether attributable to long-term natural trends during the intervening years and/or events accompanying human impingement (e.g. industrial and urban growth, port expansion measures, aquaculture, mangrove denudation etc.). Despite such large-scale alterations in benthos community structure, there were no significant changes in “biodiversity” measured through Average Taxonomic Distinctness (AvTD) and Variation in Taxonomic Distinctness (VarTD). The investigation revealed that AvTD (Δ⁺) and VarTD (Λ⁺) for previous years and the present study remained well within the 95% confidence funnel implying taxonomic stability. It was found that species, which had replaced the earlier forms, were drawn from comparable (Linnean) hierarchy i.e. same phylum/class.  相似文献   

有害藻华的宏条形码分析:机会与挑战   总被引：3，自引：3，他引：0  

陈楠生 《海洋科学》2020,44(7):116-134

宏条形码分析（metabarcoding analysis）是通过对野外样本的分子标记（即条形码）进行PCR扩增、测序，并利用测序结果分析野外样本物种组成、物种相对丰度，及其时空动态变化。这项在近20年里逐步发展起来的分子技术，得益于DNA测序技术的快速发展，包括测序通量的提升和测序成本的降低，以及生物信息学分析方法的快速开发。基于可操作分类单元（operational taxonomic units，OTUs）分析方法，特别是最近的扩增子序列变异（amplicon sequence variants，ASVs）方法的开发，极大促进了宏条形码分析的应用。在世界及我国的海洋生态领域，宏条形码分析的应用还处于起步阶段。随着分析方法的日趋成熟，可适用于不同应用领域的分子标记不断增加，以及参考数据库的不断完善，宏条形码分析将释放出广阔的应用潜力。可以预期，宏条形码分析将在系统分析我国近岸海域有害藻华物种（及其他浮游生物物种）的组成和相对丰度中起关键作用，通过发现新物种，辨别隐存种，跟踪物种的生物地理学，进而帮助解析有害藻华暴发机理。  相似文献   

南极长城站及附近岛屿南极发草的形态特征与分布   总被引：1，自引：0，他引：1       下载免费PDF全文

李学东  刘家熙  胡东  陈阜东 《极地研究》1996,8(3):64-67

南极发草是本研究地区常见的种子植物，作为南极极少的维管束植物成员之一，它在南极陆地生态系统中有着特殊的作用。本文对南极发草的分类特征和分布进行了描述，并讨论了环境变化可能影响植被发展的问题。  相似文献   

Taxonomic sufficiency in two case studies: where does it work better?     

Tiziano Bacci  Benedetta Trabucco  Sara Marzialetti  Veronica Marusso  Serena Lomiri  Danilo Vani  & Claudia Virno Lamberti 《Marine Ecology》2009,30(S1):13-19

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