大连金沙滩小型底栖生物时空分布特征及影响因素

于2015年和2016年对大连金沙滩砂质潮间带进行了季节性的调查,对小型底栖生物及其所处的沉积环境进行了研究,探讨了小型底栖的丰度、生物量和群落的时空变化及其与环境变量的关系。结果表明,金沙滩砂质潮间带沉积物主要成分为极粗砂和粗砂,年平均叶绿素a (Chl-a)质量比为0.99μg/g±1.44μg/g,年平均有机碳质量分数为0.38%±0.56%;共鉴定小型底栖生物类群15个,优势类群为海洋线虫类与底栖桡足类(二者占总丰度72.82%);小型底栖生物年平均丰度为42.52个/cm~2±42.91个/cm~2,呈现明显的季节变化和潮区差异,季节变化趋势为3月10月7月12月,潮区变化趋势为高潮带中潮带低潮带;年平均生物量为87.00μg/cm2±85.32μg/cm~2,季节变化趋势为10月7月3月12月,潮区间也存在显著差异。小型底栖生物的类群组成在季节间具有极显著差异。BIOENV分析表明,间隙水盐度、极粗砂质量比和有机碳质量分数的组合能最好地解释金沙滩小型底栖生物群落的时空分布。研究结果可为砂质滩小型底栖生物的研究提供基础数据,也可为全球气候变化背景下砂质潮间带的保护、开发和利用提供科学依据。     

深圳福田红树林保护区自由生活海洋线虫群落特征研究

分别于2013年7月(夏季)、2013年10月(秋季)、和2014年1月(冬季)在深圳福田红树林保护区选取沙嘴码头(S)、凤塘河口(F)、观鸟屋(G)和基围鱼塘(Y)四个采样区10个采样站点采集样品,探讨海洋线虫在该红树林保护区的丰度、群落结构及其时空变化规律。结果表明,福田红树林保护区海洋线虫群落平均丰度为(1 591.4±84.8) ind./10 cm~2,丰度变化范围与中国其他红树林生境基本一致。海洋线虫群落以轴线虫科(Axonolaimidae)和条线虫科(Linhomoeidae)为优势科,假拟齿线虫属(Pseudolella)、拟齿线虫属(Parodontophora)、微口线虫属(Terschellingia)、吞咽线虫属(Daptonema)、亚囊咽线虫属(Subsphaerolaimus)、后线形线虫属(Metalinhomoeus)等为优势属,刮食者(2A型)为优势摄食类型。优势属组成与中国各地红树林生境相似,表明海洋线虫群落种类组成相似。但是,仍有部分属或种的优势度仅在福田红树林生境较高,具有典型的地方性分布特点。福田红树林线虫群落结构和丰度具有显著的空间差异和季节性变化特征。季节动态主要表现为夏季丰度极高,秋冬季丰度低,三个季节种类组成区分度明显。线虫群落结构和丰度的空间差异主要表现为区域差异显著,而潮带差异不显著,表明同一区域线虫群落结构基本一致。区域差异表现为S区线虫丰度最高,F区丰度最低;线虫种类组成在Y区、S区和F区之间存在显著差异。从摄食结构而言,Y区以非选择性沉积食性线虫为优势,其他三区以刮食者为优势摄食类型。相关性分析结果显示,间隙水温度、盐度、沉积物粉砂黏土含量或中值粒径、脱镁叶绿酸、有机质含量等与线虫群落结构和丰度显著相关。植被类型差异、沉积物粒度特征的差异和有机质含量代表的食物资源差异是引起线虫群落空间差异的主要原因,间隙水温度、盐度、沉积物粒度特征的变化是引起季节差异的主要因素。海洋线虫群落的空间差异和季节性动态也是对变化中的红树林环境特征的响应。     

三亚大东海砂质潮间带小型底栖生物的时空分布及影响因素

于2015年和2016年对三亚大东海砂质潮间带进行了季节性的调查,对小型底栖生物及其所处的沉积环境进行了研究,探讨了小型底栖生物的丰度、生物量和群落的时空变化及其与环境变量的关系。共鉴定小型底栖生物类群11个,优势类群为海洋线虫类与桡足类(二者占总丰度83.13%);小型底栖生物年平均丰度为(595.77±442.72)ind·10cm~(–2),小型底栖生物2015年12月的平均丰度为(768.70±533.22) ind·10cm~(–2), 2016年6月平均丰度为(422.85±236.42) ind·10cm~(–2)。丰度分布呈现明显的季节和潮区差异。相关分析结果表明pH、偏态系数与小型底栖生物的丰度呈极显著的负相关,分选系数、中值粒径与之呈极显著的正相关性。小型底栖生物的丰度随季节变化趋势为冬季夏季。食物丰度、溶氧量升高与沉积物粒径的变化是冬季桡足类丰度的大幅增加的主要原因。TWO-WAY ANOVA与ANOSIM结果显示,潮带对小型底栖生物丰度和群落结构的影响在冬季显著。SIMPER分析结果显示,此差异主要来源为桡足类和线虫类。BIOENV分析结果显示,溶氧量和分选系数的组合最能解释这种差异。这一结果可能是由于高、中潮带的人为干扰与砂滩的清理作用导致。夏季潮带间丰度与群落结构差异不显著,pH、盐度、叶绿素含量是影响其分布的主要原因。研究结果可为砂质滩小型底栖生物的研究提供基础数据,也可为全球气候变化背景下砂质潮间带的保护、开发和利用提供科学依据。     

与网筛孔径相关的小型底栖动物群落特征——以砂质潮间带为例

于2010年7、10月和2011年1、4月,在青岛第二海水浴场和仰口海水浴场采集小型底栖动物样品,使用500、250、125、63、31μm等五个孔径的套筛对小型底栖动物样品进行分选,探讨不同大小的小型底栖动物丰度、群落结构特征和季节动态,以及影响其特征和动态的主要环境因素。两处砂质潮间带共鉴定11个小型底栖动物类群,优势类群为海洋线虫和底栖桡足类,分别占总丰度的86.34%和11.58%。第二海水浴场小型底栖动物的年平均丰度为(2 069.2±429.4)个/10 cm~2,仰口海水浴场为(1 324.8±179.1)个/10 cm~2,年平均丰度及类群组成在两处沙滩间存在显著差异。沉积物中值粒径及有机质含量、脱镁叶绿酸质量比是引起研究沙滩小型底栖动物丰度和类群组成差异的重要因素。按大小,研究沙滩小型底栖动物以63和125μm级为主,占总丰度的70.1%,其中63μm级小型底栖动物丰度最高(42.0%)。同时,两处沙滩不同大小的海洋线虫丰度存在显著的差异,第二海水浴场63μm级海洋线虫丰度最高,仰口海水浴场125μm级线虫丰度最高。线虫丰度的分级特征可以反映沉积物颗粒构成。根据小型底栖动物类群组成,可划分3组:500μm组、125和250μm组、63和31μm组,组间存在显著差异。其中,仰口海水浴场类群组成的组间差异较第二海水浴场更为明显。不同大小的小型底栖动物丰度也存在显著的季节差异。1、4和7月63μm级小型底栖动物总丰度最高。但是,10月,第二海水浴场125μm级桡足类丰度和仰口浴场125μm级线虫丰度增加,导致125μm级小型底栖动物总丰度最高。大个体线虫丰度的增加可能是对脱镁叶绿酸质量比代表的食物资源增加的反馈。不同大小的海洋线虫丰度能否有效指示栖息地的沉积环境特征仍需要大量的研究予以证实。     

南黄海潮间带海洋线虫多样性及中国海4个新纪录种记述

为了查清南黄海自由生活海洋线虫(Nematoda)种类组成和物种多样性,作者开展了南黄海沿岸潮间带自由生活海洋线虫的分类和多样性研究。通过形态学分类方法鉴定出海洋线虫247种或分类实体,其中最优势属为吞咽线虫属(Daptonema),属内个体占线虫总数的19.6%,次之为近色矛线虫属(Chromadorina)、折咽线虫属(Ptycholaimellus)和棘刺线虫属(Theristus)。最优势种为暹罗海单宫线虫(ThalassomonhysterasiamensisKito&Aryuthaka,1998),数量上占线虫总数的12.6%,其次为拟短毛吞咽线虫(Daptonema parabreviseta Huang&Sun, 2018)和眼点折咽线虫(Ptycholaimellus ocellusHuang&Wang,2011)等。描述并图示了中国4个海洋线虫新纪录种,即居中嘴咽线虫(Enoplolaimusmedius Pavljuk, 1984)、暹罗海单宫线虫(Thalassomonhystera siamensis Kito&Aryuthak...     

金门岛红树林湿地海洋线虫群落结构的初步探究

本研究于2021年2月在金门岛红树林湿地设置2个断面4个采样站位进行沉积物样品采集,对小型底栖动物的类群组成,海洋线虫群落的优势属、优势种和摄食类型等方面进行研究。结果表明：共鉴定出10个小型底栖动物类群,包括海洋线虫、桡足类、寡毛类、多毛类、涡虫、有孔虫、腹足类、涟虫、双壳类和缓步类;其中海洋线虫为最优势类群,占小型底栖动物总数的93.93%。共鉴定出海洋线虫51种或分类实体,隶属于4目15科31属。建功屿断面JH站位鉴定出11属16种,其优势属（数量百分比≥5%）为Ptycholaimellus、Viscosia、Daptonema、Dorylaimopsis、Parasphaerolaimus、Anoplostoma,优势种为Ptycholaimellus sp.1、Viscosia sp.1、Daptonema ungula、Dorylaimopsis sp.1、Anoplostoma papaviviparum; JM站位鉴定出23属35种,其优势属为Metachromadora、Daptonema、Viscosia、Ptycholaimellus、Dorylaimopsis,优势种为Metachromadora sp.1、Viscosia sp.1、Dorylaimopsis sp.1、Daptonema baihaijiaoensis、Ptycholaimellus ocellatus; JL站位鉴定出18属30种,其优势属为Daptonema、Dorylaimopsis,优势种为Daptonema quattuor、Daptonema setihyalocella、Viscosia sp.1、Daptonema baihaijiaoensis、Ptycholaimellussp.1、Spilophorella candida。古宁头断面GH站位鉴定出21属35种,其优势属为Daptonema、Parasphaerolaimus、Ptycholaimellus、Viscosia、Ptycholaimellus,优势种为Daptonema aquattuor、Daptonema setihyalocella、Viscosia sp.1、Daptonema baihaijiaoensis、Ptycholaimellus sp.1、Spilophorella candida。从群落结构来言,4个采样站位仅Daptonema为共有优势属,其他无共有优势种。从摄食类型来看,除建功屿断面中潮位的海洋线虫群落以2A型为主以外,在其他3个采样站位均以1B型为优势,故本研究海洋线虫以非选择性沉积食性者为主。     

南麂列岛火焜岙潮间带底栖纤毛虫物种多样性和群落时空分布

纤毛虫是潮间带沉积物中多样性高且丰度占优势的类群,其群落结构可反映环境状态。于2013年11月(秋季)、2014年2月(冬季)、5月(春季)和8月(夏季)开展了南麂列岛火焜岙砂质潮间带沉积物中纤毛虫物种多样性和群落结构的时空分布研究。结果表明,该生境中底栖纤毛虫物种丰富,共检获148种纤毛虫,涉及19目70余属;纤毛虫的丰度和物种组成呈现显著的季节差异和垂直分层差异。其中,丰度占优势的纤毛虫按食性依次为菌食类群、肉食类群和藻食类群;已非典型的砂隙纤毛虫区系,而是呈现出某些有机质丰富的泥沙质沉积物中的纤毛虫群落的特点,这可能是该生境受人类活动影响的后续效应。但纤毛虫物种多样性较高,这表明尽管存在人类干扰的长期效应,潮间带周边环境良好,对周边居民及设施的动迁等多样性保护措施可能已经产生了向好的结果。     

台湾海峡中北部海洋线虫群落的种类组成及分布

1998年2月对台湾海峡中北部3个断面13个取样站进行了自由生活海洋线虫调查，获得了海洋线虫100种，隶属于3目28科91属，其中密度较高的种有萨巴线虫（Sabatieria sp.1)、变异矛咽线虫（Dorylaimopsis variabilis)、Vasostoma sp．、花斑线虫（Spilophorella sp.)、吞咽线虫（Daptonema sp.)、Linhystera sp.1、吸咽线虫（Halalaimus sp.1)和（Filoncholaimus sp.)等。虽然这些海洋线虫绝大多数只鉴定江口外海降低。从优势种分布看，不同取样站其密度差异很大。海洋线虫的取食类型以选择性食沉积物者（1A）占优，有38种，但刮食性种类（2A）和非选择性食沉积物者（1B）也分别为29种和25种，表明了台湾海峡中北部海洋吸虫取食类型的复杂性。文中还探讨了海洋线虫分布与海流等环境因子的关系。     

高通量测序分析北仑河口红树林潮间带底栖真核生物分布

为了解红树林不同潮位沉积物中底栖真核生物群落分布,基于18S rRNA基因采用高通量测序方法分析了广西北仑河口陆缘、林中和海缘3个潮位红树林沉积物中底栖生物群落结构。结果表明,北仑河口潮间带红树林沉积物中底栖生物多样性丰富,Shannon-Wiener指数变化范围在6. 08～6. 73之间; PCA分析表明潮间带中底栖生物群落差异较大,陆缘红树林中扁形动物、节肢动物和软体动物相对丰度较高,林中区域中纤毛虫、环节动物和轮虫相对丰度较高,海缘红树林中硅藻相对丰度较高;红树林中主要OTUs有桡足类的太平洋纺锤水蚤(Acartia pacifica)、硅藻类的海链藻(Thalassiosira sp.)、纤毛虫类的前管虫(Prorodon teres)、多毛类的小头虫(Capitella sp.)。高通量测序方法能较全面反映红树林区微型/小型底栖生物群落,研究结果为丰富红树林底栖生物群落研究和解析底栖生物在红树林生态系统发挥的作用提供基础数据。     

山东半岛北岸不同生境潮间带浮游细菌多样性研究

通过提取山东半岛北岸不同类型潮间带海水样品的总DNA,构建16S r DNA文库,利用群落相似性分析(ANOSIM)和非度量多维尺度转换排序(NMDS),探究潮间带类型对浮游细菌群落结构的影响,并对比了与近海浮游细菌群落结构的差异。分析结果显示,浮游细菌的丰度及多样性受到潮间带类型的影响,烟台养马岛泥滩、石滩、辛安河沙滩、黄河三角洲碱蓬区和天鹅湖海草区以变形菌门占优势,而黄河三角洲米草区以拟杆菌门为优势菌,其中,天鹅湖海草区浮游细菌的丰富度和多样性最高。潮间带海水中浮游细菌的组成与近海存在显著差异,潮间带浮游细菌的丰度及多样性均显著高于近海。推测季节因素、植被类型、有机质来源可能是造成潮间带不同生境与近海浮游细菌多样性差异的重要因素。     

Meiofauna as descriptor of tourism-induced changes at sandy beaches

Tourism has long been considered as a 'clean industry' with almost no negative effects on the environment. This study demonstrated, in two different coastal systems (Mediterranean and Baltic), that tourism related activities are particularly affecting the sandy beach meio- and nematofauna in the upper beach zone, the specific ecotone in which many meiofauna species from both the marine and the terrestrial environment congregate. Tourist upper beaches are characterized by a lower % total organic matter (%TOM), lower densities, lower diversities (absence of Insecta, Harpacticoida, Oligochaeta, terrestrial nematodes and marine Ironidae nematodes) and higher community stress compared to nearby non-tourist locations. The %TOM was found to be the single most important factor for the observed differences in meiofauna assemblage structure at tourist versus non-tourist beaches in both the Mediterranean and the Baltic region. The free-living nematode assemblages from tourist upper zones depart significantly from expectations based on random selections from the regional nematode species pool. Furthermore upper zone assemblages are characterised by a low species diversity consisting of taxonomically closely related nematode species with r-strategist features. Generally, faunal differences between tourist and non-tourist beaches are decreasing towards the lower beach zones.     

Species composition and distribution of marine nematode community in the North Taiwan Strait

I~IOW~ne nelnatode is a ban gIOup of benthic OrgAnsrns. Abbot 5 000 spotes Of free-livingnelnatedes have ben dedbo so far, and it has ho estimated that abbot 20 (XX) are as yetunknoWn. Chinese bothologist has Paid attention to marine nelnatodes in China seas in yare. The spatial distribution and shoes commotion of marine nelnatedes in the HUanghe EstUary, Qinhuangdao waters, QingdaO Bay and Xiamen ~ have ho reported (Zhang etal., 1990, 1991, 1993; ac and Li, 1998). ~ new shoes in the…     

南海北部自由生活海洋线虫的群落结构和生物多样性

A quantitative study on the community structure and biodiversity of free-living marine nematodes and their relationship with environmental factors in the northern South China Sea were carried out based...     

Diversity patterns of free‐living marine nematodes in the southwest continental shelf off Bay of Bengal and their link to abiotic variables

Marine sediments in continental shelf ecosystems harbor a rich biodiversity of benthic communities. In this study, the spatial and temporal diversity and community assemblages of free‐living marine nematodes were studied by sampling at six depths and over 3 years from the southwest continental shelf off Bay of Bengal, one of the least explored tropical shelf ecosystems. The dominant marine nematode species were related with abiotic variables as part of this study. The effects of sediment granulometry generally decreased with increasing depth and the highest nematode density and species diversity were recorded on coarse sand (shallower depths). Multivariate analysis of the nematode community data showed that community structure differed significantly among depths as well as among years. Statistical analyses showed significant correlations between the nematode community and abiotic variables. Sediment texture, organic matter, water pressure and depth profile were crucial factors for determining diversity, vertical profile and feeding types of the nematode community. Other environmental factors, including anthropogenic pressure, did not have an effect on nematode diversity except for the presence of some tolerant species (Metachromadora spp., Sabatieria spp. and Siplophorella sp.). This study represents a baseline of knowledge of free‐living marine nematode communities that can be used in the future to compare nematode assemblages from temperate shelf ecosystems.     

Nematodes from wave-dominated sandy beaches: diversity,zonation patterns and testing of the isocommunities concept

Spatial patterns of nematode community structure from two geographically spaced intermediate, micro-tidal beaches (i.e. Mediterranean and Baltic) were investigated. Differences in the nematode assemblages were found to be significantly different and related to the morphodynamic characteristics of the studied zones (upper beach, swash/breakers and subtidal). Highest nematode densities and species diversities were recorded on the coarse-grained, more physically controlled, Italian beach in contrast to the more chemically controlled Polish beach. This is in contrast to the worldwide patterns of macrofaunal communities. As demonstrated by higher taxonomic distinctness measurements, upper beaches were found to harbour species from both the marine and terrestrial ecosystem and are considered to be important ecotones between these adjacent systems. The swash/breaker zones are characterised by the loss of distinctive species caused by the high water percolation in these zones. The concept of parallel ecological communities ‘isocommunities’ is only supported for the upper beach zones.     

Studies on the species composition and biodiversity of free-living marine nematodes in the southern Huanghai Sea

1 IntroductionThe conservation, persistentuse and basic re-search ofbiodiversity are increasingly becom ing oneofthe centraltopics concerned by internationalaca-dem iccirclesandothergroupsdueto itshugevaluetom ankind living and suffered seriousthreats. Fr…     

Biodiversity patterns of free-living marine nematodes in a tropical bay: Cienfuegos, Caribbean Sea

Spatial and temporal biodiversity patterns of free-living marine nematodes were studied in Cienfuegos Bay, a tropical semi-enclosed basin in the Caribbean Sea. Taxonomic (to species level) and functional (biological trait) approaches were applied for describing the assemblage structure and relating it to abiotic environment based on a sampling scheme in six subtidal stations and three months. Biological trait approach added relevant information to species pattern regarding relationships between diversity patterns and the abiotic environment. The most common morphotypes were deposit feeding nematodes, with colonising abilities of 2–3 (in a scale from 1 to 5), tail conical cylindrical or filiforme and body slender; and their abundance were correlated with depth, organic matter and silt/clay fraction. In spite of a high turnover of species, functional diversity of assemblages did not change notably in space and time. A result probably due to sampling of the habitat pool of species and to low heterogeneity of the studied muddy bottoms. Chemical pollution (organic enrichment and heavy metals) and hydrodynamic regime possibly drove the biodiversity patterns. Spatial distribution of assemblages support the existence of two well differentiated basins inside the bay, the northern basin more polluted than the southern one. The low hydrodynamic regime would determine a poor dispersion of nematodes resulting in high spatial variance in the assemblage structure; and also the associated hypoxic conditions and pollutants in sediments can explain the dominance of tolerant nematode species such as Daptonema oxycerca, Sabatieria pulchra, Terschellingia gourbaultae, and Terschellingia longicaudata. A comparison of spatial–temporal patterns of biodiversity between Cienfuegos Bay and other semi-enclosed bays in temperate regions suggests several similarities: nematode assemblages are strongly influenced by anthropogenic disturbance, temporal trends are weak or overridden by spatial ones, and few cosmopolitan genera/species tolerant to pollution and hypoxic conditions are dominant.     

Intertidal meiofauna of Jeju Island,Korea

For the first time, the structure of the meiobenthos community and marine nematodes in particular was investigated in the different intertidal zones of Jeju Island (South Sea of Korea). A relationship was found between the density of meiobenthic communities and the type of the bottom sediment. In addition, in the silty sediments, nematodes were dominant, while in the sandy sediments harpacticoids and ostracods were dominant groups. Sixty eight species belonging to 60 genera and 19 families of nematodes were found in the whole area. Four different nematode taxocenosis were distinguished using a cluster analysis. Dominant feeding groups were omnivores (2B) and epistratum-feeders (2A). The highest number of non-selective deposit-feeders (1B) was detected in the lagoon with the bottom silty sediments.     

Sublittoral meiofauna with particular reference to nematodes in the southern Yellow Sea, China

Densities of major meiofaunal taxa were investigated at 34 sampling stations during six cruises by R/V Beidou to the southern Yellow Sea, China from 2000 to 2004, and the community structure of free-living marine nematodes was studied during one of the cruises in 2003. Meiofauna abundance ranged from 487.4 to 1655.3 individuals per 10 cm². Nematodes and harpacticoid copepods were the two most dominant groups, contributing 73.8–92.8% and 3.5–18.7%, respectively, to the total meiofauna abundance. One-way ANOVA showed no significant annual fluctuation of meiofauna and nematode abundances from 2000 to 2004 in the southern Yellow Sea. However, two-way ANOVA based on six stations sampled in 4 years (2001–2004) showed that there were significant differences among the six stations and the 4 sampling years for meiofauna, nematode and copepod abundance. Correlation analysis demonstrated that meiofauna abundance was mainly linked to chloroplastic pigments. Other environmental factors could not be ruled out, however. A total of 232 free-living marine nematode species, belonging to 149 genera, 35 families and 4 orders, were identified. The dominant species in the sampling area were the following: Dorylaimopsis rabalaisi, Microlaimus sp.1, Prochromadorella sp., Promonohystera sp., Cobbia sp.1, Daptonema sp.1, Leptolaimus sp.1, Halalaimus sp.2, Aegialoalaimus sp., Chromadorita sp., Parodontophora marina, Parasphaerolaimus paradoxus, Quadricoma sp.1, Campylaimus sp.1, Halalaimus gracilis, Paramesacanthion sp.1, Paramonohystera sp.1, and Metalinhomoeus longiseta. CLUSTER and SIMPROF analyses revealed three main types of nematode community (or station groups) in the sampling area, including I: coastal community, II: transitory community between coastal and YSCWM (Yellow Sea Cold Water Mass), and III: YSCWM community. Each community was indicated by a number of dominant nematode species. Bio-Env correlation analysis between the nematode community and environmental variables showed that water depth, sediment water content, organic matter, chlorophyll a (Chl-a) and phaeophorbide a (Pha-a) were the most important factors to determine the community structure.