Latitudinal changes in larger benthic foraminiferal assemblages in shallow-water reef sediments along the Ryukyu Islands, Japan   总被引：1，自引：0，他引：1  

Kaoru  Sugihara  Naoto  Masunaga  Kazuhiko  Fujita 《Island Arc》2006,15(4):437-454

Abstract The taxonomic diversity of hermatypic corals decreases with increasing latitude, which correlates with sea‐surface temperatures. However, little is known about latitudinal changes in the taxonomic diversity and biogeographic patterns of larger benthic foraminifera, although their physiological requirements are similar to those of hermatypic corals because of their symbiotic relationships with microalgae. The present study examined how the abundance and taxonomic composition of larger foraminiferal assemblages in shallow‐water reef sediments change with latitude along the Ryukyu Islands (Ryukyus), which are located near the northern limit of coral‐reef distributions in the western Pacific Ocean. Three islands from different latitudes in the Ryukyus were selected to investigate latitudinal changes in larger foraminiferal assemblages: Ishigaki Island (24°20′N, 124°10′E), Kudaka Island (26°09′N, 127°54′E) and Tane‐ga‐shima Island (30°20′N, 131°E). Four sediment samples were taken at each of three topographic sites (beach, shallow lagoon and reef crest) on the reef flat of each island. Foraminiferal tests of a 2.0‐ to 0.5‐mm size fraction were selected, identified and counted. The variations in foraminiferal abundance in reef sediments from three latitudinally different islands exhibit two contrasting trends along reef flats: a shoreward decrease on Ishigaki and Tane‐ga‐shima Islands and a shoreward increase on Kudaka Island. A total of 25, 24 and 13 foraminiferal taxa were identified in Ishigaki, Kudaka and Tane‐ga‐shima Islands, respectively. Baculogypsina sphaerulata, Neorotalia calcar and Amphistegina spp. were dominant (i.e. >3% of foraminiferal assemblages) in the three islands. Calcarina gaudichaudii and Calcarina hispida were common on Ishigaki and Kudaka Islands but were absent on Tane‐ga‐shima Island. Larger foraminiferal assemblages from three different reef‐flat environments on Ishigaki Island can be distinguished, whereas those from the three environments on Kudaka and Tane‐ga‐shima Islands are similar in composition. These latitudinal changes in larger foraminiferal assemblages in reef sediments may possibly be caused by variations in the topography of reef flats, distributions and standing crops of living foraminifers on reef flats, and the northern limit of some calcarinid species in the northern Ryukyus.  相似文献   

海洋生物调查数据快速检核方法研究     

黄海燕  路文海  杨翼  向先全  付瑞全 《海洋通报》2015,34(2):202-208

阐述了一种海洋生物调查数据快速检核方法,以齐全性、规范性和准确性为检核内容,探讨了生物调查数据检核流程和实现方法,并以浮游植物数据检核为例进行案例分析。该方法对海洋生物种名称中存在的书写不规范、同物异名、错别字、中文名或拉丁名缺失、拼写错误等问题,实现了快速检核和批量修正,其结果对规范生物数据格式、提高物种中文名和拉丁名准确率、提高生物调查数据质量,对海洋生物数据质量控制和海洋科学研究具有一定的实践意义。  相似文献   

More about taxonomic sufficiency: a case study using polychaete communities in a subtropical bay moderately affected by urban sewage     

Pablo Muniz  Ana M. S. Pires-Vanin 《Ocean Science Journal》2005,40(3):17-33

The taxonomic sufficiency approach has been proposed as a surrogate for the typical analysis of speciesabundance data, especially in conditions involving prominent pollution gradients. Here, we evaluate the use of taxonomic sufficiency with infralittoral macrobenthic data derived from samples taken in a moderate polluted subtropical environment in southeastern Brazil, analysing five taxonomic levels and including two functional levels throughout polychaete feeding guilds and trophic groups. The data were collected seasonally at nine stations and studied for two abundance data series (0.5 and 1.0 mm sieve mesh-size). The results showed a similar ordination pattern between the two sieve mesh-size, but with the 0.5 mm sieve data a different pattern was observed during austral summer. A slight loss of information was detected using genus, family, polychaete species and their feeding guilds as taxonomic/ functional units. These results together with those of the cost/ benefit ratio, suggested that the family level seemed to be sufficient to detect the impact caused by moderate pollution in this shallow-water, subtropical environment. In additional, through the use of feeding guilds, similar patterns are obtained. Correlation analysis showed that chlorophyll a, total organic matter, zinc, and chromium sediment content were the variables that best explained the biological pattern observed and not always the best correlation coefficient occurring at the species level. The feeding guild approach seems to be useful and generates interpretable results similar to those obtained with the species level of the whole macroinfauna. The results showed an important cost reduction in the sample processing, suggesting that it is possible to adopt a coarser taxonomic level monitoring program even in species-rich communities.  相似文献   

Epibiotic assemblages on the pen shell Pinna rudis (Bivalvia,Pinnidae) at Matiota Beach,São Vicente Island,Cabo Verde     

EP Lopes  N Monteiro  AM Santos 《African Journal of Marine Science》2020,42(1):13-21

The rough pen shell Pinna rudis Linnaeus, 1758 (family Pinnidae), a mollusc with an Atlantic–Mediterranean distribution, is able to live in coarse sandy substrates. Considering its shell structure and ecological characteristics, P. rudis can enhance biodiversity by providing a substrate for settlement on its shell. For this reason, we compared the diversity of benthic taxa around P. rudis shells with the species diversity on P. rudis shells, at Matiota Beach, São Vicente Island, Cabo Verde. We sampled an area of 900 m2 and recorded data in situ to estimate the population size of P. rudis and the epibiotic and benthic community diversity. The average density of P. rudis estimated in the sampled area was 6.6 ind. 100 m–2 and the highest density was found at between 2 and 3 m depth, mostly in biogenic and sandy substrates. The epibiotic species diversity on P. rudis shells was significantly higher than the species diversity in the microhabitat around the shells. The P. rudis shell seems to play an important role in increasing the biodiversity of the ecosystem, with some species found only as epibionts on P. rudis.  相似文献   

Infrazonal biostratigraphy of the Upper Cretaceous in the East European province based on benthic foraminifers, Part 1: Cenomanian-Coniacian     

V. N. Beniamovski 《Stratigraphy and Geological Correlation》2008,16(3):257-266

A chart of infrazonal biostratigraphic subdivision of Cenomanian-Coniacian deposits in the East European paleobiogeographic province is based on distribution of benthic foraminifers. The suggested chart characterizes successive trend of changes in ecologic assemblages of benthic foraminifers and morphologic evolution of certain agglutinated (Gaudryina, Bolivinopsis, Heterostomella, Arenobulimina, Ataxophragmium, Ataxoorbignyna, Marssonella) and secretory (Globorotalites, Valvulinera, Gyroidinoides, Stensioeina, Osangularia, Berthelina, Pseudovalvulineria, Gavelinella, Cibicides, Praebulimina, Reussella) foraminiferal genera. The chart includes 7 zones and 13 subzones, most of which are recognizable over the vast territory from the Mangyshalk to southern Baltic areas. It is correlated with the acknowledged ammonoid and inoceramid zonations. Five stadia of taxonomic changes in foraminiferal assemblages, which are substantiated in this work, show that principal biotic events took place in the mid-late Cenomanian, during the Cenomanian-Turonian and early-middle Turonian transitions, in the late Turonian, and at the early-middle Coniacian boundary time.  相似文献   

Triassic ammonoids of Northeast Asia: Diversity and evolutionary stages     

A. G. Konstantinov 《Stratigraphy and Geological Correlation》2008,16(5):490-502

The history of Triassic ammonoids in the Siberian Province of the Boreal Paleobiogeographic Realm is recorded in detail in sections of Northeast Asia. In this region there are known at present 123 Triassic ammonoid genera of 41 family and 3 orders. Six stages and 14 substages are defined based on main levels of taxonomic restructuring of Triassic ammonoids, changes in their genera and families diversity, and changes in percentage of endemic and cosmopolitan taxa in assemblages. Each stage and substage is characterized by individual taxonomic composition of ammonoids, dominant groups, trends of changes in taxonomic diversity, and percentages of endemic and cosmopolitan taxa. Boundaries of ammonoid evolution stages coincide as a rule with boundaries of series and stages, whereas boundaries of evolutionary substages match those of substages. In the history of Triassic ammonoids of Northeast Asia, the periods of a rather monotonous fauna represented mainly by cosmopolitan or panboreal taxa (early Induan, early Olenekian, early Anisian, late Anisian, early Carnian, early and middle Norian) alternated with periods, typical of which were higher rates of taxa origination and endemism of ammonoids (late Induan, late Olenekian, middle Anisian, Ladinian, late Carnian). Changing degree of cosmopolitism and endemism of Triassic ammonoid faunas from Northeast Asia is shown to be connected with global eustatic sea-level fluctuations and climatic changes.  相似文献   

Taxonomic distinctness in the diet of two sympatric marine turtle species          下载免费PDF全文

Thomas B. Stringell  Wesley V. Clerveaux  Brendan J. Godley  Flora E. A. Kent  Emma D. G. Lewis  Jessica E. Marsh  Quinton Phillips  Peter B. Richardson  Amdeep Sanghera  Annette C. Broderick 《Marine Ecology》2016,37(5):1036-1049

Marine turtles are considered keystone consumers in tropical coastal ecosystems and their decline through overexploitation has been implicated in the deterioration of reefs and seagrass pastures in the Caribbean. In the present study, we analysed stomach contents of green (Chelonia mydas) and hawksbill turtles (Eretmochelys imbricata) harvested in the legal turtle fishery of the Turks and Caicos Islands (Caribbean) during 2008–2010. Small juveniles to adult‐sized turtles were sampled. Together with data from habitat surveys, we assessed diet composition and the taxonomic distinctness (and other species diversity measures) in the diets of these sympatric marine turtle species. The diet of green turtles (n = 92) consisted of a total of 47 taxa: including three species of seagrass (present in 99% of individuals), 29 species of algae and eight sponge species. Hawksbill turtles (n = 45) consumed 73 taxa and were largely spongivorous (16 species; sponges present in 100% of individuals) but also foraged on 50 species of algae (present in 73% of individuals) and three species of seagrass. Plastics were found in trace amounts in 4% of green turtle and 9% of hawksbill turtle stomach samples. We expected to find changes in diet that might reflect ontogenetic shifts from small (oceanic‐pelagic) turtles to larger (coastal‐benthic) turtles. Dietary composition (abundance and biomass), however, did not change significantly with turtle size, although average taxonomic distinctness was lower in larger green turtles. There was little overlap in prey between the two turtle species, suggesting niche separation. Taxonomic distinctness routines indicated that green turtles had the most selective diet, whereas hawksbill turtles were less selective than expected when compared with the relative frequency and biomass of diet items. We discuss these findings in relation to the likely important trophic roles that these sympatric turtle species play in reef and seagrass habitats.  相似文献   

蓄水后向家坝库区鱼类物种、分类和功能多样性变化     

熊飞  张伟  翟东东  刘红艳  陈元元  段辛斌  田辉伍  陈大庆 《湖泊科学》2024,36(1):200-212

为了解向家坝水电工程对金沙江下游鱼类多样性的影响,基于2016—2018年邵女坪(库首)、绥江(库中)和桧溪(库尾)3个江段的鱼类群落调查数据,分析了向家坝库区鱼类物种、分类和功能多样性空间格局,结合蓄水前(2011年)和蓄水初期(2015年)的资料,探讨了蓄水后向家坝库区不同维度鱼类多样性的变化趋势。向家坝库区各江段以广适性的瓦氏黄颡鱼(Pelteobagrus vachelli)和静水性的(Hemiculter leucisculus)占优势,两者的数量百分比分别为30.15%±14.82%和13.91%±11.16%。非度量多维尺度分析显示,蓄水后向家坝库区库首邵女坪和库中绥江鱼类群落差异最小,库首邵女坪和库尾桧溪鱼类群落差异最大;库中绥江在蓄水前、蓄水初期和2016—2018年3个时期的鱼类群落差异均较大,表明蓄水后绥江江段鱼类群落经历了剧烈变化。库区不同江段鱼类Margalef丰富度指数、Shannon-Wiener多样性指数和Pielou均匀度指数均表现为:桧溪>邵女坪>绥江,鱼类分类多样性指数和分类差异指数均表现为:桧溪>绥江>邵女坪。库区鱼类摄食、运动和繁殖等不同维度的功能多样性(功能丰富度、功能均匀度、功能离散度)空间格局不同,但总体上库中绥江鱼类功能丰富度最高,功能均匀度最低。与蓄水前相比,绥江江段鱼类物种、分类多样性呈下降趋势,鱼类功能丰富度和均匀度也有下降趋势。蓄水后绥江江段鱼类群落主要功能性状发生了明显变化,如蓄水前以下位口、纺锤形体型鱼类占优势,蓄水后以端位口、侧扁形体型鱼类占优势。不同维度多样性指数侧重于鱼类多样性的不同方面,结合多种指数分析有利于更全面地了解鱼类群落对环境变化和外界干扰的响应。研究结果有助于深入了解水电工程建设对金沙江下游鱼类多样性的影响,为鱼类多样性保护提供依据,也可为长江“十年禁渔”效果评估提供本底资料。  相似文献   

Dynamic and Physical Considerations on the Asteroids Density     

Birlan  Mirel 《Earth, Moon, and Planets》2000,88(1):1-10

High quality new data on the asteroid mass and volume were produced in the last years from both extra-atmospheric instruments and the groundbased high-performance telescopes. This paper presents a synthesis of these resultsin terms of the asteroid density, taking into account several techniques, and the possible correlation of the density through the taxonomic system. The important conclusion is that M-type asteroids seems to have an unexpected low density, which cannot be explained by the present mineralogy assumed by the comparative mineralogy. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

贡嘎山东坡林地土壤的诊断特性与系统分类   总被引：10，自引：0，他引：10  

何毓蓉  张保华  黄成敏  周红艺  程根伟 《冰川冻土》2004,26(1):27-32

贡嘎山东坡寒区林地在海拔2200～3650m的典型土壤,其土壤诊断层和诊断特性主要有暗瘠表层、漂白层、雏形层、石质接触面特征、常湿润土壤水分状况和寒冻、寒性、冷性或温性土壤温度状况.由于泥石流和冰川堆积物对所发育土壤性状有很大影响,提出了划分泥石流岩性特征和冰碛物岩性特征及其诊断指标.根据本区土壤诊断层和诊断特性,按照中国土壤系统分类对研究区典型土壤进行了检索,在分类中首次根据泥石流岩性特征和冰碛物岩性特进行了土壤系统分类.  相似文献