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1.
球形棕囊藻(Phaeocystisglobosa)暴发藻华时多以囊体形态出现,但迄今缺乏囊体消除方法研究。本文在球形棕囊藻藻华暴发水域取样进行实验,比较了原土及不同改性材料制备的改性粘土对囊型球形棕囊藻的消除效果,并考察了水体pH、溶解有机碳(DOC)、溶解无机磷(DIP)等在治理前后的变化。结果表明:粘土经表面改性后对球形棕囊藻消除能力明显提高,对囊体亦有一定破碎作用,且改性粘土浓度越高,其除藻破囊效果越好;在有效消除囊体细胞情况下,添加改性粘土对水体中pH及DOC含量影响较小,但可以导致DIP水平降低。 相似文献
2.
球形棕囊藻是我国沿海常见有害藻华物种,生活史中包括囊体和单细胞两种形态,藻华爆发时的优势形态是囊体,游离单细胞很少被发现,但是球形棕囊藻囊体形成的机制目前还不清楚。本研究通过分析桡足类、纤毛虫和异养甲藻及其化学信号对囊体形成的影响,以探究摄食压力对球形棕囊藻生活史转变的影响。实验结果表明:3种摄食者的直接摄食均引发了球形棕囊藻囊体直径的扩大,摄食者的粒径越大,球形棕囊藻的囊体直径增大越显著,安氏伪镖水蚤的化学信号也能引发球形棕囊藻囊体显著增大,但是游仆虫和海洋尖尾藻的化学信号并未引发类似响应。囊体形成和直径的扩大保护了囊体内细胞免受摄食,有助于球形棕囊藻藻华的发生。 相似文献
3.
2021年1月下旬深圳大鹏湾沿岸海域发生球形棕囊藻(Phaeocystis globosa)藻华。为了探究球形棕囊藻藻华发生动态特征及其影响因素, 于1月20日至2月1日系统调查分析了藻华发生过程中浮游植物优势种演替、球形棕囊藻囊体数量、营养盐水平以及其他环境因素的变化。结果表明: 1月20日, 中肋骨条藻(Skeletonema costatum)为绝对优势种, 1月21日球形棕囊藻囊体开始出现, 1月25日囊体数量达到最高, 达69colonies·L-1; 1月27日红色赤潮藻(Akashiwo sanguinea)藻华出现, 随后球形棕囊藻藻华逐渐消退。灰关联分析显示, 铵盐和硝酸盐是影响球形棕囊藻囊体丰度的最主要因素。水体扰动和球形棕囊藻在磷限制条件下的竞争优势也可能有利于球形棕囊藻藻华的发生。红色赤潮藻藻华可能是球形棕囊藻藻华消退的主要原因。球形棕囊藻藻华的发生和消亡是各种理化因素和生物因素共同作用的结果。 相似文献
4.
球形棕囊藻具有异型的生活史,能够在单细胞和囊体两种不同形态之间转换。球形棕囊藻藻华现场发现,囊体有时附着在角毛藻上。为研究角毛藻对囊体形成的影响和机制,进行球形棕囊藻和小角毛藻的共培养实验,观察球形棕囊藻囊体的形成和生长状况,研究小角毛藻对球形棕囊藻囊体形成的影响。结果证明:混合培养下,小角毛藻和球形棕囊藻的囊体附着在一起,在较短的生存周期内,囊体的密度明显高于单独培养时的密度;而单独培养体系下,棕囊藻单细胞密度和囊体体积均高于混合培养,囊体的存在时间较长。小角毛藻的存在对囊体的形成具有促进效应,这对于球形棕囊藻囊体具有重要的生态意义。硅藻的存在更能体现球形棕囊藻竞争优势。 相似文献
5.
球形棕囊藻(Phaeocystis globosa Scherffel)是全球海洋广泛分布的有害藻华种类。1997年10月,中国东南沿海首次暴发了此种藻类的大规模藻华,其后陆续在福建、广东、广西、海南、河北及天津等省市沿海暴发多起同种藻华。中国近海的球形棕囊藻藻华呈现两大独有的特点,即藻类囊体较大(可达3厘米),以及藻华可毒害养殖业。历经20多年,球形棕囊藻在中国沿海已从一个"藻华新记录种"变成了"藻华常见种"。值得注意的是, 2014年以来,广西北部湾海域棕囊藻藻华肆虐,威胁核电冷源安全,受到了社会高度关注,也对球形棕囊藻藻华的研究提出了新的挑战与要求。针对这一生态灾害的最新发展趋势,本文总结了20年来中国球形棕囊藻及其藻华灾害的发生与发展状况,分别就棕囊藻的分类、生活史特征、营养特性、藻华形成的环境驱动因素、生态毒理等诸多方面开展简要综述,冀望为棕囊藻藻华的研究及防治提供基础资料及思路。 相似文献
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球形棕囊藻(Phaeocystis globosa)常在热带至温带近海海域形成有害藻华,该种具有种内遗传多态性,且有囊体大小、特征色素组成等性状分化。在我国南海形成有害藻华的球形棕囊藻可形成“巨型囊体”,以19''-丁酰氧基岩藻黄素(But-fuco)为特征色素,是一种独特的“巨囊”生态型。2021年11月底至12月初,南黄海青岛沿岸暴发大规模球形棕囊藻藻华。藻华发生期间,对青岛沿岸3个站位的水文和化学要素进行了观测,分析了球形棕囊藻囊体的数量、直径和色素组成,并应用一种高分辨率种下分子标记——叶绿体rbcS-rpl27基因间隔区分析了其遗传特征。结果表明,藻华发生期间青岛沿岸表层海水温度较低 (12~14℃),海域营养盐组成具有高溶解有机氮、低溶解无机氮的特征;球形棕囊藻囊体丰度超过20个/L,最大囊体直径为18 mm,以But-fuco为特征色素, rbcS-rpl27序列分析表明其与南海“巨囊”生态型球形棕囊藻具有相同的遗传特征。南黄海首次暴发的球形棕囊藻藻华是由“巨囊”生态型形成,该藻华可能对海洋生态系统、水产养殖业发展和核电设施运行等构成威胁,亟待开展藻华成因与监测预警对策研究。 相似文献
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棕囊藻引发的有害藻华已经成为一种全球性的自然灾害,给海洋环境以及渔业经济带来了严重的损失。棕囊藻存在两种生活史形态:游离的单细胞形态和囊体形态,但是不同形态之间的转换和囊体形成机制尚不清楚。营养盐是浮游植物生长和藻华发生的物质基础,棕囊藻藻华以往多发生在硝酸盐限制海区。但是近年来,尿素等有机氮在河口区域浓度不断提高,有机氮源的增加可能对棕囊藻生长和生活史转换产生显著的影响。通过添加硝酸盐、铵盐、尿素三种氮源,研究不同氮源对球形棕囊藻生长和囊体形成的影响。研究表明:球形棕囊藻可以在硝氮、尿素中迅速生长,形成囊体,但是氨氮对其却有明显的抑制作用;球形棕囊藻单细胞在硝氮中丰度比较高,最大可达到(444.21±64.97)×10~3个·mL~(-1);在尿素中更容易形成囊体,最多能达到(12.61±6.5)个·mL~(-1)。球形棕囊藻可以利用硝酸盐和有机氮源使其具有更强的竞争力,尿素在海洋水体中浓度的提高,可能是近年来球形棕囊藻藻华在我国近海水域频发的原因之一。 相似文献
8.
球形棕囊藻(Phaeocystis globosa)是我国北部湾海域主要的有害藻华原因种, 囊体的生长是藻华发生和持续的关键。为了研究在富营养化日趋严重的钦州湾海域中营养盐输入对球形棕囊藻藻华形成的影响, 采集钦州湾含球形棕囊藻的表层海水进行了添加不同营养盐的室内培养实验。根据钦州湾历史调查数据, 进行了不同营养盐、不同氮磷比和不同添加方式的培养。结果表明, 同时添加氮和磷显著促进浮游植物的生长, 球形棕囊藻囊体继浮游植物细胞密度高峰期后大量形成。一次性添加磷对囊体生长的刺激作用较添加氮时强, 丰度最高可达4.8×103 colonies·L–1, 囊体平均直径为(115±84) μm, 且具有较高囊体细胞密度, 但囊体衰退较快。单独添加氮时, 囊体细胞分布稀疏, 囊体数量及直径皆较低。每天添加磷的方式相比一次性添加更有利于囊体丰度的维持。总体上, 磷营养的添加能刺激囊体数量、囊体细胞数和囊体直径的生长。在具有较高N/P比值的钦州湾, 应加强磷的排放管理, 避免突发性磷污染对球形棕囊藻囊体生长的刺激作用。 相似文献
9.
近年来, 棕囊藻已成为我国北部湾海域藻华发生的主要原因种, 严重影响北部湾海洋生态环境、水产增养殖业和防城港核电安全, 急切需要对棕囊藻藻华原因种作进一步分析确认。2017年2月和3月在钦州湾和涠洲岛藻华发生海域分离得到9株棕囊藻, 采用光学显微镜进行形态学初步鉴定, 并通过核糖体小亚基序列(SSU rDNA)进行系统进化分析。研究结果表明, 北部湾9株棕囊藻与球形棕囊藻形态特征基本符合, 系统发育树与不同海域来源的球形棕囊藻聚在同一大分支上, 与其他海域来源的球形棕囊藻遗传距离为0.0000~0.0071, 其中北部湾WZS3-1株与墨西哥湾株CCMP627、苏里南株CCMP628、厄瓜多尔株CCMP1528、南非株P162、中国海株RCC:K1398及汕头株Santou97的球形棕囊藻亲缘关系最近, 遗传距离为0.0000, 而北部湾WZS1、WZS2、WZS4、WZS5株与香港株SKLMP_T005和渤海株BOHAI1亲缘关系最近, 遗传距离为0.0000。球形棕囊藻的种内遗传距离(0.0000~0.0073)明显小于种间遗传距离(0.0084~0.0440), 因此可确定来自北部湾不同海域的9株棕囊藻均为球形棕囊藻。此外, 球形棕囊藻各藻株间的亲缘关系远近与其地理位置分布不能完全对应。本研究结果将为我国棕囊藻藻华藻种库构建、棕囊藻北部湾株生理生态研究和北部湾棕囊藻藻华发生机理研究等提供参考。 相似文献
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11.
球形棕囊藻(Phaeocystis globosa)是中国近海常见的有害藻华原因种,游离单细胞和球形囊体是其异型生活史的两种形态。本研究通过添加KH2PO4(PO43-)、卵磷脂(LEC)、三磷酸腺苷二钠(ATP)、葡萄糖-6-磷酸钠盐(G-6-P)、和核糖核酸(RNA)5种不同磷源进行室内培养,以阐明不同磷源对球形棕囊藻生长及囊体形成的影响。结果表明,5种磷源培养条件下皆可形成囊体,以G-6-P为磷源的球形棕囊藻生长最优,囊体密度最大可达(5.7±0.5)×105colonies·L-1,在培养中后期诱导产生较高的碱性磷酸酶活性(181.1±41.6)nmol·h-1·L-1有利于其高生物量及囊体形态的维持。以PO43-为磷源时,囊体密度最大可达(6.1±0.7)×105colonies·L-1,但对囊体形态的维持较G-6-P组差。以LEC或RNA为磷源时,囊体密度及叶绿素a含量较低,囊体单位表面积的细胞密度更高,结构更紧致。LEC组的囊体直径最大,可达(488.2±220.6)μm。以ATP为磷源时,囊体细胞分布稀疏,囊体衰退较快。4种有机磷源对球形棕囊藻囊体的构建存在不同程度的影响,在自然水体棕囊藻藻华形成及维持中,除无机磷源外部分形态的有机磷源可能会发挥重要作用。 相似文献
12.
海洋浮游植物棕囊藻Phaeocystisspp.在自然界常以游离单细胞和由粘胶质包裹的细胞集群体两种细胞形式轮换出现,它在世界各营养丰富的海域中无处不在,并可形成高细胞密度、暴发性繁殖及形成赤潮。rRNA基因研究数据说明,目前全世界海洋分布的Phaeocystisspp.有3个分开种,即Phaeocystispouchetii、Phaeocystisglobosa和Phaeocystisantarctica。棕囊藻奇特的生理学和生态学特征是独一无二的,它复杂的多形态变化生命循环导致海域植物性和海底食物网(如微量元素的生物地球化学)的结构与功能均发生了极大的变化。棕囊藻的生命循环体现了其主要的生态学特征,不同棕囊藻形态的生物化学和营养代谢与细菌,微型、中型和后生浮游动物的作用以及海洋环境中的物理结构均有关。在自然界,棕囊藻的生命循环中最常见和最重要的是它的集群体形态,集群体形态是一个具有整体生物学功能特征的生物实体。棕囊藻在生态系中起到重要作用的关键在于集群体形态在合成糖粘胶质的能力较强。 相似文献
13.
Molecular identification of bloom-forming species Phaeocystis globosa(Prymnesiophyta)and its dispersal based on rDNA ITS sequence analysis 总被引：3，自引：1，他引：3
Abstract-The colony-forming Phaeocystis species are causative agents of dense bloom occurrences incoastal waters worldwide. It is difficult to separate them because of the different morphologies associatedwith their colonial stages. In this study we applied molecular approaches to analyze the genetic variationof Phaeocystis globosa and Phaeocystis pouchetii from several geogrtaphic regions, and to assist in tracingthe dispersal of bloom-forming Phaeocystis species in coastal waters of China. The Sequences of the inter-nal transcribed sacers (ITS1 and ITS2) of rDNA and the 5.8S ribosomal RNA gene of Phaeocystisstrains were determined. Sequence comparison shows that P.globosa was the most divergent toP. pouchetii, exhibiting sequence divergence higher than 0.08. However, lower genetic divergences ex-isted between strains of P.globosa. The sequence comparison of the Phaeocystis rDNA ITS clearlyshows that the species isolated from the southeast coast of China is identified as P. globosa rather thanP. cf. po 相似文献
14.
While prokaryotes play key roles in nutrient cycling and energy flow during Phaeocystis globosa blooms, the information on the spatial and diel temporal distribution of the prokaryotic community during Phaeocystis blooms remains scarce. In January 2019, we used high-throughput sequencing of the 16S rRNA gene to explore the spatial and diel variations of particle-attached (PA) and free-living (FL) prokaryotic communities during the blooming phase of P. globosa in Beibu Gulf, Guangxi, China. The results suggested a significant spatial variation pattern in the horizontal distribution of prokaryotic communities, while there was no significant difference in the vertical direction. Both spatial distance and environmental variables shaped the horizontal distribution of the prokaryotic community structure, while environmental variables, particularly the abundance of P. globosa colony and Chl a, showed more significant influence and were closely related to the structure and variation of the prokaryotic community. Strong vertical mixing of the water column disrupted the vertical structure heterogeneity of the prokaryotic community in winter. There were significant differences in the diel samples of PA prokaryotic communities, but not in the FL prokaryotic communities. Nitrate, ammonium and the abundance of P. globosa colony were the key environmental variables impacting the diel variations of prokaryotic communities over the sampling period. The present study provided valuable information to depict the spatial-temporal variations of the microbial community and its association with environmental parameters during P. globosa bloom in the tropical gulf. 相似文献
15.
Abstract. Ecology and morphology of Alcyonium (Parerythropodium) coralloides were studied in different sites of the Eastern Atlantic and the Mediterranean. The species is extremely variable in size, colony shape and colour. In the Mediterranean population, encrusting red colonies are mostly encountered, although lobate colonies also exist. White and pink colonies are considered mutants, which tolerate the stable environment of deeper habitats better than the conditions encountered in shallow biotopes. Mediterranean colonies are dioecious and reproduce sexually. In the Eastern Atlantic, lobate pink colonies are the most common form, and show little variability. These (at least partly) parthenogenic populations are considered offspring from stray larvae from more southern regions. This explains the rather patchy distribution of the Atlantic populations, as compared to the widespread distribution throughout the entire Western Basin of the Mediterranean and the Adriatic Sea. A study of the most important systematic characters of the species (growth form, sclerites and solenial network) leads to the conclusion that coralloides belongs to the genus Alcyonium. As a result, coralloides being its type-species, the genus Parerythropodium will have to be suppressed. 相似文献
16.
张金标 《海洋学报(英文版)》1985,4(1):113-120
The geographical distribution and seasonal abundance of Pleurobrachia globosu are analyzed on the basis of 806 samples taken from 91 stations in six sea areas along the southeast coast of China from April I960 to January 1979. This ctenophore species is seen in small quantities without evident annual peak, while it is seen throughout the year in southern Fujian in great quantities with three peaks. The annual quantity of the animal decreased gradually from southern Fujian northward and appeared in shorter periods. The peak number of annual quantity decreased gradully as well. It is tentatively concluded that in low temperatures (less than 25.5‰) salinity is a limiting factor for the dis-tribution of P. globosa while temperature takes over the control when salinities are low (less than 21.5‰)-The T-S-P diagram may be used to predict the occurrence of "bloom" of these animals and be useful for aquaculture in preventing unnecessary losses due to the predation of P. globosa. 相似文献
17.
B. Velimirov 《Marine Ecology》1980,1(2):155-168
Abstract. An experiment to test C have's hypothesis on temperature dependent MgCO3 concentrations in marine calcareous skeletons was undertaken by transplanting colonies of Heliopora coerulea. The corals were transferred from a shallow lagoon with high average temperatures to the outer bottom of a fringing reef, 16 m depth, with low average temperatures. Against expectation, a statistically significant increase of average mol % concentrations from 0.48 to 0.54 % for upper growth regions and from 0.49 to 0.62% for lower growth regions was obtained. Temperature records during the experimentation period and the above data indicate that the mol% MgCO3 concentration in the skeleton of living Heliopora colonies increases when transplanted to an environment with a lower temperature average than that of their original growth site, and with seasonal temperature fluctuations which are smaller in the experimental site than in the control site. Temperature fluctuations at the control site were up to 2.5 times greater than at the experimental site for most of the observation months. This supports the conclusion that the parameters a) minimum temperature and b) temperature stability of the environment are essential for the incorporation of Mg into the carbonate skeleton matrix of marine organisms. Within this study the results of a quantitative chemical analysis of the carbonate skeleton of H. coerulea are presented and growth data of transplanted colonies compared with those from the control site. 相似文献