香港水域夏季微型浮游动物摄食研究

20 0 0年 8月在香港牛尾海 ( A站 )和龙鼓水道 ( B站 )的 2个典型站位采样 ,用半现场的稀释法研究了夏季香港水域浮游植物的生长率和微型浮游动物对浮游植物的摄食压力等。结果表明 :A、B站浮游植物主要以硅藻为主 ,但 A站甲藻比重比 B站要高。A站 <5 μm的微型浮游植物比 B站要少 ,从细胞大小上 B站的浮游植物更易被微型浮游动物所摄食。A站微型浮游动物类群主要以异养鞭毛藻为主 ,而 B站为砂壳纤毛虫 ,其细胞丰度分别为 770和 62 0 ind./L。 A、B站浮游植物碳 /叶绿素 a浓度比率分别为 2 7.1 5和88.66。 A站浮游植物的内禀生长率相似于 B站 ,分别为 1 .0 4和 0 .98d- 1。浮游植物在 A站的净生长率是0 .33d- 1,而在 B站则出现了负增长 ,其净生长率是 - 0 .5 8d- 1。微型浮游动物在 A、B站的摄食率分别为0 .71和 1 .5 6d- 1,摄食压力分别占到了浮游植物现存量的 1 43.7%和 2 0 9.7% ,初级生产力的 78.6%和1 2 6.6% ,对浮游植物碳的摄食率分别达到 35 1和 5 5 2 μg C/( L·d)。A站的浮游植物生长要高于 B站 ,B站的微型浮游动物摄食压力要明显高于 A站。与其它海区比较香港水域微型浮游动物摄食压力处于中等水平。黑暗长时间培养实验的结果表明此水域微型浮游动物摄食率稀释法实验应在适量添加营养盐并在     

獐子岛海域冬季分级叶绿素a的分布特征及其影响因素

于2016年1月对獐子岛海域进行了航次调查,研究了獐子岛海域浮游植物粒级结构的空间分布特征及其环境影响因素。结果表明:冬季表层总叶绿素a、小型(20μm)、微型(2~20μm)和微微型(0.45~2μm)浮游植物叶绿素a浓度的范围分别为0.24~0.92、0.15~0.58、0.09~0.46、0~0.03μg·L-1,平均叶绿素a的浓度分别为0.69、0.36、0.33、0.002μg·L-1,小型、微型和微微型浮游植物对浮游植物总量的贡献率分别为51.72%、48.01%、0.26%;底层总叶绿素a、小型、微型和微微型浮游植物叶绿素a浓度的范围分别为0.29~1.77、0.12~1.45、0.17~0.50、0μg·L-1,平均叶绿素a的浓度分别为0.78、0.43、0.34、0μg·L-1,小型、微型和微微型浮游植物对浮游植物总量的贡献率分别为52.97%、47.03%、0;从垂直分布上来看,表、底层总叶绿素a及两种粒级浮游植物(20μm、2~20μm)的浓度均差异不显著,分布较为均匀;从水平分布上来看,总叶绿素a及两种粒级浮游植物(20μm、2~20μm)浓度的表、底层空间分布趋势相近,均呈现出由獐子岛海域西北部向南部逐渐降低的趋势。RDA分析表明,温度、盐度、溶解氧、颗粒态有机物、NO2--N和NH4+-N是影响獐子岛海域冬季浮游植物粒级结构变动的重要因素。     

春季赤潮频发期东海微型浮游动物摄食研究

2002年4～5月在东海长江口及其邻近水域的8、11、14、23和28号5个典型站位采样。用现场稀释法对春季东海水域浮游植物的生长率和微型浮游动物对浮游植物的摄食压力等方面进行了研究．结果表明,微型浮游动物的摄食行为在东海赤潮过程起到关键作用．各站位微型浮游动物主要以急游虫、红色中缢虫和夜光藻为主,在种类上砂壳纤毛虫是主要的类群．微型浮游动物的摄食速率范围在0．28～1．13d-1,对浮游植物现存量的摄食压力范围在35．14％～811．69％。对浮游植物潜在初级生产力的摄食压力范围在74．04％～203．25％,对浮游植物碳的摄食率范围在9．58～97．91μg·L-1·d-1,靠近岸边的站位,微型浮游动物的摄食速率、对浮游植物现存量的摄食压力和对浮游植物碳的摄食率相对较高。而远离岸边的站位对浮游植物潜在初级生产力的摄食压力却较高．与世界其它海区比较此水域微型浮游动物摄食压力处于较高水平．急游虫是控制东海主要赤潮原因生物具齿原甲藻生长的关键种类．     

獐子岛及邻近海域秋季浮游植物的粒级结构及其影响因素

于2015年10月对獐子岛及邻近海域进行了航次调查,研究了獐子岛及邻近海域浮游植物粒级结构的空间分布特征及其环境影响因素。结果表明,秋季表层总叶绿素a、小型(20μm)、微型(2—20μm)和微微型(0.45—2μm)浮游植物叶绿素a浓度的范围分别为0.52—1.25、0.03—0.81、0.33—0.91、0—0.09μg/L,平均叶绿素a的浓度分别为0.76、0.19、0.53、0.03μg/L,对叶绿素a总量的贡献率分别为23.77%、72.26%和3.98%;底层总叶绿素a、小型(20μm)和微型(2—20μm)浮游植物叶绿素a浓度的范围分别为0.14—1.5、0.04—1.04、0.08—0.47μg/L,平均叶绿素a的浓度分别为0.46、0.22、0.24μg/L,对叶绿素a总量的贡献率分别为41.46%、58.50%。从垂直分布上来看,总叶绿素a浓度垂直变化为,表层底层;小型浮游植物垂直分布较为均匀;微型浮游植物垂直变化为,表层底层;微微型浮游植物垂直变化为,表层底层,且在表、底层均保持较低水平。秋季表层微型浮游植物(2—20μm)浓度与盐度呈正相关。底层总叶绿素a浓度与磷酸盐浓度呈正相关,小型浮游植物(20μm)浓度与磷酸盐和硅酸盐浓度均表现为正相关,微型浮游植物(2—20μm)浓度与温度呈正相关。统计分析结果表明,温度、盐度、磷酸盐及硅酸盐浓度是影响獐子岛及邻近海域秋季浮游植物粒级结构变动的重要因素。     

北部湾北部海域夏季微型浮游动物对浮游植物的摄食压力

2011年8月份于北部湾北部海域5个观测站位获得的分层水样,分析了表层叶绿素a含量和表层微型浮游动物丰度以及类群组成;同时于现场采用稀释培养法研究了该海域浮游植物生长率(μ)和微型浮游动物的摄食率(g)。分析和测定结果表明:调查海区的微型浮游动物丰度400—1167个/L,类群组成以无壳纤毛虫为主;浮游植物的生长率为-1.50—1.13 d-1,微型浮游动物摄食率为0.33—1.08 d-1;推算微型浮游动物对浮游植物现存量以及初级生产力的摄食压力分别为28.1%—66.0%和-7.4%—438.4%。相对于中国其他海区,8月份北部湾北部海域微型浮游动物摄食速率处于中等水平。调查期间,广西沿海高生产力海区,浮游植物生长率大于微型浮游动物动物的摄食率,浮游植物生物量处于积累期;涠洲岛以南海域,浮游植物生产力较低,微型浮游动物摄食作用是控制浮游植物生长的重要因素。     

铁皮石斛茎段离体快繁

1　植物名称　铁皮石斛 (Ｄｅｎｄｒｏｂｉｕｍｃａｎｄｉｃｕｍ)。2　材料类别　幼嫩茎段。3　培养条件　基本培养基为ＭＳ。芽增殖培养基 :(1 )ＭＳ +ＮＡＡ 0 .1～ 0 .5ｍｇ·Ｌ- 1 (单位下同 ) +6 ＢＡ 0 .5～ 2 .0 ;壮苗培养基 :(2 )ＭＳ无激素培养基 ;生根培养基 :(3 ) 1 /2ＭＳ +ＩＢＡ 0 .1。以上各种培养基蔗糖浓度均为 3 .0 % ,ｐＨ 5 .4～ 5 .8,培养温度 (2 5 +2 )℃ ,连续光照培养 ,光照强度 1 5 0 0ｌｘ。4　生长和分化情况4.1　丛生芽诱导　剪取幼嫩茎段 ,按常规表面灭菌后 ,切成约 2 .0ｃｍ左右的切段 ,每一切段应至少保留 …     

春末三峡大坝首次蓄水期长江口浮游植物群集

根据2003年6月三峡大坝第1次蓄水期长江口及其邻近水域(28°-33°N,120°-125°E)34个测站采集的浮游植物水样,报道了该水域浮游植物群集特征.结果表明:调查区浮游植物以硅藻和甲藻为主,伴有少量的绿藻和金藻.浮游植物细胞丰度介于0.2～1504.2 cells·ml-1,平均为72.7 cells·ml-1,主要优势物种为骨条藻(Skeletonema sp.)、具齿原甲藻(Prorocentrum dentatum)和锥状施克里普藻(ScrippsieUa trochoidea).调查区表层两个浮游植物密集区分别位于北部的冲淡水域和西南部近岸水域.浮游植物细胞丰度最大值出现在中层(10m层),最小值出现在底层.冲淡水域的优势物种是骨条藻,主要出现在表层;而在长江冲淡水与台湾暖流、黄海混合水交汇的水域,优势物种为具齿原甲藻,主要分布在表层和中层.     

秦皇岛海域微微型藻华期间叶绿素a分级研究

2011年6月秦皇岛北戴河海域暴发微微型浮游植物赤潮,对北戴河海域进行了3次海域调查,探讨和分析了秦皇岛海域赤潮暴发期间的6月和非赤潮期间的7、8月表层浮游植物的粒级结构分布特征,并对环境因子进行了相关影响分析.赤潮期间整个调查海域范围内叶绿素a(Chl.a)平均含量为10.85±5.13μg/L,非赤潮期间7月、8月Chl.a的平均含量为5.50±3.60μg/L.赤潮期间和非赤潮期间各粒级浮游植物Chl.a含量对Chl.a总量的贡献率有所差异,赤潮期间6月小型(Microphytoplankton,>20μm)、微型(Nanophytoplankton,2～20μm)和微微型(Picophytoplankton,0.74～2μm)浮游植物对总Chl.a的贡献率分别为2.1%、48.3%和49.6%.非赤潮期间7月小型、微型、微微型对总Chl.a的贡献率分别为14.4%、51.6%、24.0%.通过浮游植物粒径分级Chl.a和环境因子的相关性分析,发现在赤潮期间调查海域浮游植物Chl.a与硝酸盐的相关性系数随着浮游植物粒径的增大而从负逐渐变正.发现在非赤潮区微型和微微型浮游植物与OD显著正相关(p<0.01).     

胶州湾叶绿素a浓度及浮游植物的粒级组成

2008年2、5、8和11月对胶州湾及邻近水域中表层叶绿素a浓度和浮游植物粒级组成进行了调查.结果表明:胶州湾内和湾外表层叶绿素a年平均浓度分别为4.90和2.03 mg·m^-3;叶绿素a浓度的平面分布呈现自东北部及近岸向中部、南部及湾外递减的趋势;叶绿素a浓度季节变化明显,冬季和夏季浓度较高,春季次之,呈现温带海域双峰型的变化趋势.胶州湾浮游植物粒级组成以微型浮游植物为主,平均占叶绿素a总量的60.9%,其次是小型浮游植物,超微型浮游植物所占比例最低,与我国近海浮游植物粒级组成基本一致.与历史资料相比,微型浮游植物所占比例有所增加,超微型浮游植物所占比例降低.     

春季季风转换期间孟加拉湾的初级生产力

2010年中国科学院东北印度洋科学考察期间,对孟加拉湾水域初级生产力展开了研究.孟加拉湾表层水体的水温较高,盐度变化范围较大,且上层水体营养盐含量较低,在真光层底部营养盐浓度突然增加.表层叶绿素a浓度较低(＜0.1 mg/m3),叶绿素a最大值常出现在75 m水深处,上层水体浮游植物的生长受氮限制明显.表层潜在初级生产力低于0.2mgcm-3h-1,且初级生产速率在50-75 m出现最大值.水柱中初级生产力变化范围为199-367 mgCm-2d-1,高值出现在88°-89°(E)附近.浮游植物固碳的主要贡献者是微微型浮游生物(＜3 μm),其次是小型浮游生物(＞20 μm)和微型浮游生物(3-20 μm),但表层与75 m水深处固碳浮游植物的结构有一定差异.将孟加拉湾与阿拉伯海初级生产力进行对比,孟加拉湾水体初级生产力显著低于阿拉伯海,且初级生产力的影响因素有着显著的差异.     

Breeding ecology and nest site selection in allopatric mainland Citril Finches Carduelis[citrinella] citrinella and insular Corsican Finches Carduelis[citrinella] corsicanus

The breeding ecology and nest site selection of mainland Citril Finches and insular Corsican Finches have been studied throughout their limited range. For many years both endemic forms were considered to be two sub-species; however, based on evidence from more recent molecular studies they have been split into two species. This study provides data on the variations in breeding ecology and nest site selection in the different sub-populations of these little studied species. A secondary aim was to search out evidence of ecological differentiation between mainland Citril Finches and insular Corsican Finches. We found that the studied sub-populations of both species largely overlapped in breeding ecology. Our data confirms the close similarity of Citril Finches and Corsican Finches, both which are, similar to mountain birds, well adapted to the local habitat conditions of their different mountain systems. Several differences were identified within the studied sub-populations of the two (sub-) species with respect to nest site selection, probably caused by environmental conditions and local predators. One of the main differences between the two species is that Citril Finches breed mainly in half-open conifer forests (especially pine forests), while Corsican Finches breed in the more open scrubby mountains of the Mediterranean islands dominated mainly by the Tree Heath as an adaptation to the different landscapes on the islands. In contrast to Citril Finches, this preference of the Corsican Finches for Tree Heath as nesting plants – even if suitable pines are available – is typical of the species. These behavioural changes result in a niche expansion into open habitats at lower altitudes. We suggest that the observed niche expansion and behavioural variations are not suitable criteria for taxonomic status, a proposal in contrast to that of Sangster [Ibis 142:487–490 (2000)]. We further suggest that the few ecological differences found in this study between the two (sub-)species are the result of the so-called insular syndrome, which includes changes in life history traits such as morphology, demography and behaviour.     

Population-Scale Foraging Segregation in an Apex Predator of the North Atlantic

In this work we investigated the between-colony spatial, behavioural and trophic segregation of two sub-populations of the elusive Macaronesian shearwaters Puffinus baroli breeding only ~340 km apart in Cima Islet (Porto Santo Island) and Selvagem Grande Island. Global location sensing (gls) loggers were used in combination with the trophic ecology of tracked individuals, inferred from the isotopic signatures of wing feathers. Results suggest that these two Macaronesian shearwater sub-populations do segregate during the non-breeding period in some ‘sub-population-specific’ regions, by responding to different oceanographic characteristics (habitat modelling). Within these disparate areas, both sub-populations behave differently (at-sea activity) and prey on disparate trophic niches (stable isotope analysis). One hypothesis would be that each sub-population have evolved and adapted to feed on particular and ‘sub-population-specific’ resources, and the segregation observed at the three different levels (spatial, behavioural and trophic) might be in fact a result of such adaptation, from the emergence of ‘cultural foraging patterns’. Finally, when comparing to the results of former studies reporting on the spatial, behavioural and trophic choices of Macaronesian shearwater populations breeding on Azores and Canary Islands, we realized the high ecological plasticity of this species inhabiting and foraging over the North-East Atlantic Ocean.     

The relevance of flow cytometry for biochemical analysis

Flow cytometry (FCM) allows the simultaneous measurement of multiple fluorescences and light scatter induced by illumination of single cells or microscopic particles in suspension, as they flow rapidly through a sensing area. In some systems, individual cells or particles may be sorted according to the properties exhibited. By using appropriate fluorescent markers, FCM is unique in that multiple structural and functional parameters can be quantified simultaneously on a single-particle basis, whereas up to thousands of biological particles per second may be examined. FCM is increasingly used for basic, clinical, biotechnological, and environmental studies of biochemical relevance. In this critical review, we summarize the main advantages and limitations of FCM for biochemical studies and discuss briefly the most relevant parameters and analytical strategies. Graphical examples of the biological information provided by multiparametric FCM are presented. Also, this review contains specific sections on flow cytoenzymology, FCM analysis of isolated subcellular organelles, and cell-free FCM.     

DNA quantification in colorectal carcinoma using flow and image analysis cytometry

Numerous studies using flow cytometry (FCM) have shown that DNA quantification and ploidy classification can provide information of prognostic significance for patients with colorectal carcinoma; recent advances in image analysis cytometry (image cytometry, ICM) provide a new, alternative technique for DNA quantification. This study investigated whether (1) patients with colorectal carcinomas that exhibit a diploid pattern of DNA distribution have improved five-year survival statistics as compared to their non-diploid counterparts and (2) ICM provides quantitative data comparable to that obtained by FCM. DNA quantification and ploidy classification of 27 cases of primary colorectal carcinoma was performed on archival paraffin-embedded tissue by both FCM and ICM; 70% (19) of the tumors were classified as nondiploid by ICM while 56% (15) were similarly classified by FCM. Diploid tumors were associated with Dukes' stage A while nondiploid tumors were associated with Dukes' stage D. The overall five-year survival rate was 75% for patients with ICM diploid tumors and 67% for patients with FCM diploid tumors. The five-year survival was only 53% for patients with nondiploid tumors identified by both techniques. This study confirmed that DNA quantification is an important prognostic indicator for patients with colorectal carcinoma. It also showed that ICM provides data comparable to that of FCM and may be more sensitive.     

New method to characterize microbial diversity using flow cytometry

The majority of microorganisms have yet to be cultivated and represent a vast uncharacterized and untapped resource. Here, we report the utilization of a combination of flow cytometry, cultivation, and molecular genetics to develop new methodologies to access and characterize biodiversity in microbial samples. We demonstrate that fluorescent dyes and combinations of dyes can selectively stain portions of bacterial populations that can be isolated as sub-populations using fluorescence-activated cell sorting (FACS). Microbial sub-populations obtained by FACS differ substantially from the original microbial population, as demonstrated by denaturing gradient gel electrophoresis and determination of 16S rRNA gene sequences. These sub-populations can subsequently be used to inoculate microbial growth media, allowing the isolation of different microbial species from those that can be readily cultivated from the original sample using the same microbial growth media. When this technique was applied to the analysis of activated-sludge and Yellowstone Lake hydrothermal vent samples, comparative analysis of 16S rDNA sequences revealed that FACS allowed the detection of numerous bacterial species, including previously unknown species, not readily detectable in the original sample due to low relative abundance. This approach may result in a convenient methodology to more thoroughly characterize microbial biodiversity.     

Flow cytometry in cytopathology. Overview and perspectives

The future applications of flow cytometry (FCM) are briefly discussed. Whereas the early goals of its clinical applications were cancer diagnosis and classification, it has now become apparent that FCM can more successfully provide information on a variety of cell constituents of crucial importance in the evaluation of tumor prognosis and treatment sensitivity. It is suggested that (1) the data being provided by FCM will probably lead to a more clinically relevant classification of tumors, based more on the biochemical/molecular markers of individual cells and an assessment of tumor heterogeneity and less on classical cell morphology and tumor progression, and (2) FCM seems likely to become established as a routine methodology in cytopathology.     

A brief note on the resemblance between relatives in the presence of population stratification

Population stratification occurs when a study population is comprised of several sub-populations, and can result in increased false positive findings in genomewide-association studies. Recently published work shows that sub-population-specific positive assortative mating at the genotypic level results in population stratification. We show that if the allele frequency of a single nucleotide polymorphism responsible for a trait varies between sub-populations and there is no dominance variance, then the heritability of the trait increases, primarily due to an increase in the additive genetic variance of the trait.     

Male red deer (<Emphasis Type="Italic">Cervus elaphus</Emphasis>) dispersal during the breeding season

Breeding dispersal can be of significant ecological and evolutionary importance. Yet, it is seldom considered in mammals. I present data on male red deer (Cervus elaphus) movements between sub-populations in southern Sweden during the rut. I investigated whether these movements could be breeding dispersal driven by mate competition. During the ruts of 1998–2009, I recorded 91 movements of males. The longest movement distance was 18.5 km. Dispersal was not restricted to yearlings or sub-adults, but also observed among adult stags. Of 91 movements observed, 7 were made by yearlings, 46 by sub-adults and 38 by adults. There was a significant move among yearlings and sub-adults towards areas with a higher ratio of females/adult males and towards areas with more females. The movements between rutting areas thereby seemed driven by sexual competition.     

Remarks on branching-extinction evolutionary cycles

We show in this paper that the evolution of cannibalistic consumer populations can be a never ending story involving alternating levels of polymorphism. More precisely, we show that a monomorphic population can evolve toward high levels of cannibalism until it reaches a so-called branching point, where the population splits into two sub-populations characterized by different, but initially very close, cannibalistic traits. Then, the two traits coevolve until the more cannibalistic sub-population undergoes evolutionary extinction. Finally, the remaining population evolves back to the branching point, thus closing an evolutionary cycle. The model on which the study is based is purely deterministic and derived through the adaptive dynamics approach. Evolutionary dynamics are investigated through numerical bifurcation analysis, applied both to the ecological (resident-mutant) model and to the evolutionary model. The general conclusion emerging from this study is that branching-extinction evolutionary cycles can be present in wide ranges of environmental and demographic parameters, so that their detection is of crucial importance when studying evolutionary dynamics.