River flow influence on the fish community of the Tagus estuary (Portugal)

The influence of river flow on the fish community was assessed for the Tagus estuary (Portugal), based on sampling surveys carried out between 1979 and 2002. Four estuarine areas were sampled using similar fishing gear and effort in all the years considered in this study (1978–1980; 1995–1997; and 2001–2002). According to river freshwater flow values, sampling years were classified as wet (mean value of 714 m³ s⁻¹, sd = 110 m³ s⁻¹) or dry (mean value of 164 m³ s⁻¹, sd = 19m³ s⁻¹). Species richness varied between 22 and 39 according to the year, but no significant differences were related to river flow. The number of species per ecological guild was also similar in wet and dry years. Fish assemblage was dominated by marine occasional, estuarine resident and marine-estuarine opportunist species that represented near 90% of all fish species. The highest densities were represented by estuarine resident species. Fish density in dry and wet years differed significantly (mean density of 10.51 individuals 1,000 m⁻² and 3.62 individuals 1,000 m⁻², respectively), and the major differences were registered for estuarine resident, marine-estuarine opportunist and catadromous species. These differences probably reflected the estuarine habitat availability and also differences in fish densities in some estuarine areas under different flow conditions. The multivariate ordination analyses performed outlined both seasonal and spatial variation trends in fish distribution and abundance. The estuarine longitudinal gradient and its relationship with species distribution were less evident in dry years. Relationships between species abundance and river flow were different according to species, which is probably due to different needs in the timing and magnitude of river flow. Electronic supplementary material  The online version of this article (doi: ) contains supplementary material, which is available to authorized users.     

海洋有害赤潮的生物防治对策

该文综述了海洋有害赤潮治理的生物方法。细菌、寄生虫和病毒等微型生物是天然水体中具有调节藻类种群动态平衡的重要潜在因子,它们的繁殖速度非常快,并具有宿主的专一性,是一种非常有潜质的赤潮调控因子。根据生态系统中的食物链关系,通过引入赤潮生物的天敌来防治赤潮也是一种治理方法。浮游动物和一些滤食性的贝类在水体中与赤潮生物共存,并能以这些赤潮生物为食,是具有明显赤潮治理功效的生物控制剂。另一方面,利用大型海藻与微藻间的相生相克和营养竞争等作用在养殖区域内进行赤潮的防控被认为具有较强的理论和实践意义。该文详细介绍了上述方法的原理、可行性以及局限性,并就今后的研究方向进行了展望。     

Terrestrial ecologists ignore aquatic literature: Asymmetry in citation breadth in ecological publications and implications for generality and progress in ecology

The search for generality in ecology should include assessing the influence of studies done in one system on those done in other systems. Assuming generality is reflected in citation patterns, we analyzed frequencies of terrestrial, marine, and freshwater citations in papers categorized as terrestrial, marine and freshwater in high-impact “general” ecological journals. Citation frequencies were strikingly asymmetric. Aquatic researchers cited terrestrial papers ~ 10 times more often than the reverse, implying uneven cross-fertilization of information between aquatic and terrestrial ecologists. Comparisons between citation frequencies in the early 1980s and the early 2000s for two of the seven journals yielded similar results. Summing across all journals, 60% of all research papers (n = 5824) published in these journals in 2002–2006 were terrestrial vs. 9% freshwater and 8% marine. Since total numbers of terrestrial and aquatic ecologists are more similar than these proportions suggest, the representation of publications by habitat in “general” ecological journals appears disproportional and unrepresentative of the ecological science community at large. Such asymmetries are a concern because (1) aquatic and terrestrial systems can be tightly integrated, (2) pressure for across-system understanding to meet the challenge of climate change is increasing, (3) citation asymmetry implies barriers to among-system flow of understanding, thus (4) impeding scientific and societal progress. Changing this imbalance likely depends on a bottom-up approach originating from the ecological community, through pressure on societies, journals, editors and reviewers.     

长江中上游主要经济鱼类的渔业生物学特征

根据1996－1999年长江中上游渔业资源监测资料,分析了青鱼,草鱼,链,鳙,铜鱼,圆口铜鱼,长吻Wei,河鲶,瓦氏黄颡鱼,鲤等10种主要经济鱼的渔业生物学特性,并应用von Bertalanffy公式,Key公式,Beverton-Holt公式等估计了生长参数,总死亡系数,自然死亡系数,捕捞死亡系数,总存活率,总死亡率,自然死亡率,捕捞死亡率和开发率,讨论了资源的开发状况,针对存在的问题,提出了渔业管理意见。     

海洋放线菌研究进展

海洋放线菌因其产生独特的次生代谢产物而备受世界的关注。本文以海洋放线菌的研究历史为主线,综述了海洋放线菌研究的发展历程,海洋放线菌的概念、生物资源、多样性及其分布状况、次生代谢产物以及基因组研究等方面,探讨了其生态功能,最后展望了我国海洋放线菌研究存在的问题及未来发展的前景。     

四个类群海洋蛭弧菌类生物生长特性的比较

研究了噬菌弧菌科(Bacteriovoracaceae) 4个类群共12株海洋蛭弧菌类生物(Bdellovibrio- and-like organisms, BALOs)的生长温度和盐度范围及其对6种常见对虾病原弧菌的裂解能力, 并通过透射电镜分析了其中4个代表菌株的形态特征。结果表明, 同一群或亚群内菌株的生长温度或盐度相同, 即类群IV、VI、IX、X菌株的生长温度范围分别为20°C~35°C、15°C~35°C、15°C~ 40°C和10°C~40°C, 最适生长温度为30°C或35°C; 生长盐度范围分别为5‰~40‰、2.5‰~30‰、5‰~60‰和5‰~60‰, 最适生长盐度分别为10‰、5‰、20‰和20‰。测试的6种弧菌中有3种可被全部BALOs裂解, 而其它弧菌仅被部分BALOs裂解, 但即使同一类群菌株, 对某些弧菌也表现不同的裂解能力。形态上, 4株不同类群BALOs均呈典型的弧状细胞, 具极生单鞭毛。     

AHLs对小球藻PS Ⅱ光化学活性与光合作用关键酶的影响

采用批次培养的方法,研究了100、200和300 nmol/LC₁₀-HSL(N-癸酰-L-高丝氨酸内酯)对普通海水小球藻(Chlorella vulgaris)PSⅡ光化学活性与光合作用关键酶的影响。结果显示:在C₁₀-HSL作用下,小球藻生长受到促进,细胞密度显著升高,而且存在着随C₁₀-HSL浓度上升促进作用增强的剂量-效应关系;小球藻PSⅡ光化学活性指标——最大光能转化效率F_v/F_m、实际光能转化效率Yeild及表观光合电子传递效率ETR明显提高,而且C₁₀-HSL对Yeild的作用强于对F_v/F_m的影响;小球藻光合作用关键限速酶——核酮糖-1,5-二磷酸羧化酶/加氧酶Rubisco、磷酸丙糖异构酶TPI、焦磷酸:果糖-6-磷酸-1-磷酸转移酶PFP、果糖-1,6-二磷酸醛缩酶FDA活性均不同程度上升,表明小球藻光合固碳及合成糖类的能力有所增强。     

中国东海和南海海域可培养烃类降解细菌的筛选及功能

【背景】海洋环境中蕴藏着丰富的微生物资源,其种类繁多而且功能多样,在驱动物质循环及能量流动等方面起着重要的作用。目前,海洋中烷烃化合物降解菌的分离筛选和降解功能研究已有文献报道;但是对海洋中尤其是我国东海和南海海域,具有降解芳香烃类化合物功能的菌株分离筛选及其多样性研究鲜有报道。【目的】分离筛选我国东海和南海海域具有烃类降解能力的可培养菌株,并对其降解功能和多样性进行初步研究。【方法】分别从东海和南海海底沉积物样品中筛选菌株,选择不同的烃类化合物为菌株筛选的唯一碳源,采用梯度稀释和平板划线法分离纯化得到单菌落,并利用相应烃类为唯一碳源进行生长验证获得该化合物降解菌。【结果】以肉桂酸、碱木素、十六烷等12种烃类化合物为唯一碳源,从样品中共分离到63株具有烃类化合物降解能力的菌株,分别属于3个门4个纲8个目10个属,主要为红球菌属(Rhodococcus)、不动杆菌属(Acinetobacter)、弧菌属(Vibrio)、盐单胞菌属(Halomonas)、假单胞菌属(Pseudomonas)。两大海域优势降解菌差别较大,其中东海沉积物降解菌株主要为不动杆菌属(Acinetobacter),而南海沉积物降解菌株主要为红球菌属(Rhodococcus)。【结论】我国东海和南海海域蕴藏着丰富的烃类化合物降解菌株资源,两大海域优势降解菌种类存在明显差异,这将为我国未来可能的海洋环境石油污染的微生物治理储备菌种资源。     

海洋微生物中二酮哌嗪类化合物的研究进展

二酮哌嗪类化合物的基本结构是由两个氨基酸缩合而成的环二肽, 因其骨架具有稳定的六元环结构, 且有两个氢键给体和两个氢键受体, 使得DKPs具有较强的生物活性和药理活性, 在药物化学中成为一个重要的药效团。近年来从海洋微生物中发现一系列环二肽类化合物, 研究表明其功能不局限于抗菌、细胞毒活性等方面,在群体感应调控机制中也充当着信号分子的重要角色, 已成为化学生态学的研究热点。本文综述了近年来二酮哌嗪类化合物在海洋微生物代谢产物中的研究进展, 并对其研究方向进行了讨论和展望。     

1株新抑锈病素产生菌FIM03-1149的分离鉴别

在寻找新型抗真菌抗生素的过程中,从海洋放线菌FIM03-1149发酵液中分离到抗真菌抗生素新抑锈病素(Neorustmicin)。菌株FIM03-1149在多数培养基上生长良好,淡黄-橙黄色,无气生菌丝,不产生可溶性色素。形态特征、化学分类特征和生理生化特性等研究表明菌株FIM03-1149属于小单孢菌属。16SrRNA基因序列分析也表明菌株FIM03-1149属于小单孢菌属,但与最接近已知种Micromonospora siamensisTT2-4T处于不同的进化分支,2个菌株在某些生理生化特性上也有不同。基于上述数据,菌株FIM03-1149可能是小单孢菌属的1个新种。