Solid sand particle addition can enhance the production of resting cysts in dinoflagellates     

杨傲傲  胡章喜  唐赢中 《中国海洋湖沼学报》2018,(2)

Resting cysts are an important part of the life cycle for many harmful algal bloom-forming dinoflagellates, and play vital roles in the recurrence and geographical spread of harmful algal blooms. Numerous factors have been suggested to regulate the formation of resting cysts, although only a few have been proven to be significant. Cyst formation can be induced by adverse environmental conditions such as drastic changes in temperature, light, salinity, and nutrient levels, and by biological interactions. In this study, we evaluated the ability of an artificial factor(fine sand particles) to enhance the formation of resting cysts. Fine sand particles were added to cultures of dinoflagellates that are known to produce cysts. The addition of fine sand particles significantly increased both the production rate and final yield of cysts in cultures of S crippsiella trochoidea, Biecheleria brevisulcata, and Levanderina fissa(= Gymnodinium fissum, Gyrodinium instriatum, Gyr odinium uncatenum). The largest increase in the final yield(107-fold) of cysts as a result of sand addition was in S. trochoidea. However, addition of fine sand particles did not induce cyst formation, or barely af fected cyst formation, in A kashiwo san guinea, Cochlodinium polykrikoides and Pheopolykrikos hartmannii, which are also known to be cyst-producing species. We speculated that addition of sand significantly increased the chances of cell collision, which triggered cyst formation. However, further research is required to test this idea. Importantly, our findings indicate that the addition of fine sand particles is a useful method to obtain a large quantity of cysts in a short time for laboratory studies or tests; for example, if a cyst viability test is being used to assess the eff ectiveness of ships' ballast water treatment.  相似文献   

潍坊滨海区开采卤水对资源及环境的影响   总被引：1，自引：0，他引：1       下载免费PDF全文

郭建勇  刘桂珍  徐金欣  王兰中 《山东国土资源》2008,24(7)

野外实地调查、室内水质化验分析、图件制作和大量数据统计表明,按现状开采规模开采卤水,将导致地下水降落漏斗形成,并使卤水浓度、溴和氯化钠平均含量逐年降低,以及卤水资源面临枯竭等一系列问题,其根本原因是卤水开采规模过大。因此,大幅度压减卤水开采规模,是卤水资源可持续开发并保护好地质环境的有效途径。  相似文献   

浙江沿岸上升流锋区特征及其成因的初步探讨   总被引：5，自引：0，他引：5  

潘玉球  曹欣中  许建平 《海洋湖沼通报》1982,(3)

浙江近海在夏季存在一条锋区,这已为大家所熟知。这一锋区,渔业生产上正在密切注视着它,海洋工作者也在对它进行研究。以前的工作是从水团分析的角度出发的,其目的是为中心渔场的确定提供依据。本文试图通过1980年7—8月间浙江沿岸上升流专题调查对其实体进行研究,给出其夏季的特征结构,并对其成因提出初步看法。 1980年夏季的上升流调查,是专题性的综合调查。观测项目有温度(包括BT)、盐度、海流、海洋化学因子,并采集生物标本等。观测基本上是在偏南风的同一天气形势下进行的。因此,利用这些资料来讨论浙江沿岸上升流的锋区特征及其成因,有一定的意义。  相似文献   

草鱼出血病病毒的研究进展   总被引：12，自引：1，他引：12  

李军  王铁辉  陆仁后  陈宏溪 《海洋与湖沼》1999,30(4):445-453

根据８０－９０年代中国关于草鱼出血病病毒研究的进展,就草鱼出血病病毒的发现、形态结构特征、理论特性、基因组结构及其所编码的多肽、基因组的转录和翻译过程,病毒的繁殖动态、体外细胞培养特性,病毒对鱼体的致病机理和宿主范围,草鱼出血病的诊断和防治等问题进行综合评述,总结概括了草鱼出血病病毒的研究现状以及研究中需要亟待解决的问题,并提出该领域以后的重点研究方向。  相似文献   

北京中轴线偏离子午线的分析     

夔中羽 《地球信息科学学报》2005,7(1):25-27

1 北京南北中轴线不是正南正北向 北京南北中轴线(以下简称北京中轴线)不是正南正北,这中轴线不在子午线上。北京中轴线与子午线不重合,而是偏西北北方向。明朝以后,这中轴线南起永定门,北至钟楼,约8km。往北离永定门越远的建筑,离子午线就越远。以通过永定门的子午线为准,钟楼就向西偏离这条子午线近300m了。元、明、清三朝30几位皇帝的宝座都是歪的,歪得不太多,向逆时针方向偏转2度多。  相似文献   

《海洋工程》征稿简则     

《海洋工程》是中国海洋学会主办的综合性学术刊物  已被中国学术期刊文摘中国科学引文数据库中国学术期刊光盘版 《海洋工程》1999

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