Relation of body weight and food consumption to metabolic rate of juvenile Japanese sea bass,Lateolabrax japonicus

ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅＪａｐａｎｅｓｅｓｅａｂａｓｓ (ＬａｔｅｏｌａｂｒａｘｊａｐｏｎｉｃｕｓＣ＆Ｖ)ｄｉｓｔｒｉｂｕｔｅｓｗｉｄｅｌｙｉｎｔｈｅｃｏａｓｔａｌｗａｔｅｒｓａｌｏｎｇｔｈｅＢｏｈａｉＳｅａ ,ＹｅｌｌｏｗＳｅａ ,ＥａｓｔＣｈｉｎａＳｅａ,ａｎｄＳｏｕｔｈＣｈｉｎａＳｅａ .Ａｓａｃａｒｎｉｖｏｒｏｕｓｆｉｓｈ ,ｉｔｏｃｃｕｐｉｅｓｔｈｅｈｉｇｈｔｒｏｐｈｉｃｌｅｖｅｌｉｎｔｈｅｍａｒｉｎｅｅｃｏｓｙｓｔｅｍａｎｄｈａｓａｄａｐｔｅｄｔｏｖａｒｉｏｕｓｅｎｖｉｒｏｎｍｅｎｔａｌｒ…     

海带中砷在大鼠体内代谢过程中的形态变化

研究了海带中砷元素在大鼠体内代谢过程中的形态变化。采用Wistar大鼠按体重随机分为空白对照组和高剂量海带组、低剂量海带组,每组10只,雌雄各半,分别灌胃基础饲料和添加50%、25%海带粉(占饲料粉的比例)的饲料。实验结束后,取大鼠血液、胃内容物、回肠内容物、回盲部内容物和大肠末端内容物,采用高效液相色谱-电感耦合等离子体质谱法(HPLC-ICP-MS)测定样品中的砷形态和含量。结果表明,海带中的砷在大鼠体内代谢过程中形态发生变化;空白对照组大鼠胃、回肠、回盲部和大肠末端的内容物中砷含量较低,主要砷形态为二甲基砷(DMA)和五价砷(AsⅤ),且不含有砷糖化合物;添加海带组大鼠胃、回肠、回盲部、大肠末端内容物中含有砷糖化合物及少量的砷胆碱(AsC)、砷甜菜碱(AsB)、DMA和AsⅤ,海带中的砷在大鼠的大肠末端主要以砷糖和小分子有机砷形态排出体外。空白对照组和添加海带组大鼠血液中的砷形态均为DMA和少量AsⅤ,添加海带组大鼠血液中未检出砷糖化合物。本研究旨在为阐明海带中砷元素在体内的代谢变化提供参考依据。     

广西武鸣盆地岩溶泉口浮游生物群落对水环境变化的响应

近年来我国西南岩溶地区一些岩溶泉出现水生生态系统由草型向藻型转变的问题,但水化学监测却显示泉水水质依旧良好.岩溶泉的水质变化与水生生态系统退化不同步,故探寻岩溶泉水环境的变化以及浮游生物群落的响应,对全面掌握和客观评价泉水的健康状况具有重要意义.于2016年7月、2020年7月两个时期对广西武鸣盆地内4个岩溶泉进行了浮...     

Fate of the Black Sea Acartia clausi and Acartia tonsa (Copepoda) penetrating into the Marmara Sea through the Bosphorus

In October 2005 spatial distribution of live and dead Acartia clausi and Acartia tonsa was studied in the Black and Marmara Seas and near the Marmara Sea inlet of the Bosphorus, in order to understand their fate upon transportation between two seas. The morphometric characteristics in both species from all studied areas, and the decreased abundance of A. clausi and A. tonsa from the Black Sea towards the Marmara Sea indicate that the Marmara Sea Acartia populations are formed by recruitment from the Black Sea. We observed mass mortality of A. clausi in the Marmara Sea near the Prince Islands. The majority of carcasses (66% of total A. clausi numbers in the Marmara Sea) were found in the salinity gradient layer.     

不同处理对蓖齿眼子菜(Potamogeton pectinatus L.)种子萌发率的影响

2001年9月和2002年8、9月对内蒙古锡林郭勒盟几个小型盐湖的浮游生物群落特征进行了研究调查.共检出浮游植物59种(属),优势种类为:线形粘杆藻、针晶蓝纤维藻、小席藻、微小平裂藻、舟形藻、绿裸藻、普通小球藻、盐生杜氏藻和衣藻等;浮游动物34种(属),优势种类为:膜袋虫、裸口虫、四膜虫、纤毛虫、褶皱臂尾轮虫、萼花臂尾轮虫、蒙古裸腹溞、卤虫、咸水北镖水蚤和新月北镖水蚤等．浮游植物生物量以达格尔淖最高,平均为166.56mg/L;其次是扎格斯台淖为106.77mg/L;再次是夏日淖和桑根达莱淖,分别为6.39mg/L和2.83mg/L,变动幅度较小.浮游动物生物量以桑根达莱淖最高,平均为24654mg/L,变动幅度较大;其次是扎格斯台淖为27.24mg/L,再次为夏日淖和达格尔淖,分别为12.01mg/L和2.76mg/L.文中讨论了内陆盐水浮游生物的种类组成、分布、生物量和盐度耐性与盐度、营养盐、碱度、pH及离子组成的关系等问题.     

Effects of macroalgal blooms on carbon and nitrogen biogeochemical cycling in photoautotrophic sediments: an experimental mesocosm

The effects of floating macroalgae (250 g DW m⁻²) on photoautotrophic microbenthos were studied in a flow-through mesocosm with a parallel mesocosm without macroalgae serving as Control. Vertical microprofiles of O₂ at the sediment-water interface showed a immediate and complete suppression of photosynthetic activity of microphytobenthos (MPB) under the macroalgal canopy, resulting in a shift of benthic metabolism from autotrophic to heterotrophic. MPB abundance and chlorophyll a content decreased and a change from a diatom-dominated to cyanobacteria-dominated community was observed. Inorganic nitrogen nutrients´ concentrations increased in the porewater as a result of the inhibition of MPB nutrient demand, leading to an increase in net ammonification and anaerobic consumption rates. No organic matter transfer from macroalgae to the sediment was detected, resulting in a net consumption of the carbon and nitrogen stored in the sediment. In consequence, sediment was progressively impoverished in nitrogen, reducing sediment nutrient regeneration.     

一株自太湖微囊藻上分离到的细菌的生长及磷代谢

磷是引起湖泊水华爆发的关键元素,微囊藻（Ｍｉｃｒｏｃｙｓｔｉｓ）是太湖水华的主要藻种,为了研究磷在湖泊水体低级食物链（细菌、浮游动植物等）中的代谢,以一株自太湖微囊藻上分离的假单胞菌（Ｐｓｅｕｄｏｍｏｎａｓ ｓｐ．）Ｘ菌株为试验菌,研究了磷形态及生长因子对其生长的影响,结果表明无机磷浓度对Ｘ菌生长的影响不大,而ＡＴＰ对Ｘ菌的生长有抑制作用;在含有无机磷和有机磷的培养基中,Ｘ菌优先利用无机磷盐,Ｘ菌     

温度对微食物网生物代谢的影响

生态学代谢理论(metabolic theory of ecology, MTE)指的是生物的代谢速度随着温度的升高而增加,随生物个体大小(即生物量)的增加而异速增长。根据MTE理论可预测异养过程与自养过程对温度的反应不同,低温对异养代谢的抑制要明显;而随着温度升高,异养代谢升高的速度比自养代谢升高的速度要快。MTE理论可以对海洋浮游微食物网生物的代谢研究进行理论指导,用于解释一些低温造成的海洋浮游生态学现象,以及预测全球变暖的影响。多年来人们一直根据MTE理论开展理论分析和实验检验,发现低温会抑制细菌和微型浮游动物的生长,并可以降低微型浮游动物的摄食率。春季高纬度海区的海水温度会抑制细菌的生长,而浮游植物则几乎不受影响,从而造成春季水华发生。温度和底物浓度是冷海(水温≤4℃)细菌生长率低的原因,但在永冷海(周年温度≤4℃的海区,包括极地海区和深海的大部分)中究竟是低温还是底物浓度限制了细菌的生长率仍被争论。全球变暖的预测认为本世纪海洋表层温度会升高2～6℃。根据MTE理论,温度升高对自养和异养过程的影响不同,围隔实验证明全球变暖将导致水华与细菌、水华与微型浮游动物的时滞变小,促进微型浮游动物对细菌和浮游植物的摄食,改变有机物质自养生产和异养消耗之间的平衡,使更多的物质和能量进入呼吸作用,使得生态系统变得更加异养。但在温度升高对海洋细菌生长效率和细菌生物量变化的研究方面,MTE理论还有一定的局限性,需要进一步的理论分析和实验检验。     

Comments on: “Underwater measurements of carbon dioxide evolution in marine plant communities: A new method” by J. Silva and R. Santos [Estuarine,Coastal and Shelf Science 78(2008) 827–830]

Silva et al. propose a new method for quantifying benthic net community production (NCP) of tidal flats under submerged condition, based on the monitoring of water pCO₂ in a transparent benthic chamber around high tide. I demonstrate here with theoretical considerations that this method is inappropriate for coastal environments, because it allows only the quantification of the change in the dissolved CO₂ which, at classical seawater pH, is only ∼10% of the change of the dissolved inorganic carbon (DIC). Total Alkalinity and/or DIC must be measured at the beginning and end of incubations in order to compute NCP in coastal environments. However, I also demonstrate that when pH is below 7, more than 95% of the DIC change occurs in the CO₂ pool. The method proposed by Silva et al. is thus valuable for freshwater environments with acidic, low alkalinity waters, where monitoring the water pCO₂ in a vial or chamber provides alone a very close approximation of the planktonic or benthic net community production.     

甲壳动物争斗行为研究进展

争斗残食已成为制约甲壳动物集约化养殖提质增效的瓶颈之一。甲壳动物的争斗行为受诸多外部因素影响,同时受机体生理代谢和基因调控。本文介绍了甲壳动物争斗行为的研究方法,概述了争斗行为的影响因素、生理代谢特征及基因调控等研究成果,提出了系统开展甲壳动物争斗行为量化的必要性及机制研究方向,以期为深入研究甲壳动物争斗行为奠定基础。