长江口赤潮高发区浮游植物与水动力环境因子的分布特征

报道了2002年春季长江口海域(30°50′～31°50′N,121°50′～123°00′E)的22个大面观察站和一个昼夜连续观察站的水样和网样浮游植物的种类组成、丰度分布与水动力环境因子、营养盐的关系．结果表明,长江口区共有浮游植物5门45属110种．主要赤潮生物优势种为中肋骨条藻(Skeletonema castaturn)和具齿原甲藻(Prorocentrum dentatum)等．浮游植物丰度的昼夜变化白天大于夜间,垂直分布不明显．浮游植物主要生态类型可划分为：沿岸河口低盐半咸水类群、沿岸偏低盐广布性类群、外海高盐暖水性类群等．长江口区浮游植物丰度在1．6×10^3～75．2×10^3个.dm-3．浮游植物的种类组成和丰度分布与长江冲淡水密切相关．在该区域存在三股不同性质的水,即长江河口水、长江冲淡水及外海水(台湾暖流)影响着浮游植物的分布．     

长江口及邻近海域浮游磷虾类数量和分布的季节特征

根据2002～2003年长江口29°00′～32°00′N、122°00′～123°30′E海域4个季节的海洋调查,运用定量、定性方法,探讨长江口邻近海域浮游磷虾类总丰度的季节变化特征以及与渔场的关系,丰度的季节差异与水团的关系,分析了优势种的数量变动、对磷虾类的贡献及对环境的适应情况,并与东海外海的生态特征作了比较。结果表明,长江口及邻近海域磷虾类丰度季节变化主要受温度的影响,平面分布变化与盐度有关。平均丰度夏季最高（10.46ind/m3）,冬季最低（0.32ind/m3）。本次调查共发现8种,优势种为中华假磷虾（Pseudeuphausia sinica）、太平洋磷虾（Euphausia pacifica）和小型磷虾（Euphausia nana）,其中中华假磷虾四季皆为优势种,太平洋磷虾是春、秋和冬季的优势种,小型磷虾仅仅是春秋季的优势种。中华假磷虾在春、夏和冬季对总丰度的贡献率较高,并占绝对优势,其更适应夏季咸淡水交错水域的环境,而太平洋磷虾和小型磷虾更适应东海近海暖温高盐环境。长江冲淡水势力强弱和中华假磷虾的数量对磷虾类时空分布有重要影响,中华假磷虾对咸淡水环境的适应则是影响该种数量变化的另一个重要原因。     

东海海樽类生态类群统计分析

依据1997～2000年在东海23°30′～33°00′N、118°30′～128°00′E4个季节的海洋调查资料,采用曲线拟合,构造数学模型和极大值分析等数学方法,研究海樽类最适温度和盐度,籍此进一步分析其生态类群。结果表明,Yield Density模型可以应用于大多数海樽类最适温度和盐度的统计推断。依据物种分布的最适温度和盐度值,并参考其地理和季节分布特征,认为梭形纽鳃樽（Salpa fusiformis）属暖温带外海种;羽环纽鳃樽长柄亚种（Cyclosalpa pinnata polae）和安纽鳃樽（Ritteriella amboinensis）为热带大洋种;双尾纽鳃樽东方亚种（Thalia decocratica orientalis）、小齿海樽（Doliolum denticulatum）和软拟海樽（Dolioetta.gegenbauri）等其余13种为亚热带外海种。海樽类多数物种可以作为水团的指示种。梭形纽鳃樽往往出现在沿岸水和外海水混合水团偏高盐水一侧。羽环纽鳃樽长柄亚种高丰度分布在台湾暖流控制的水域,是台湾暖流的指示种。双尾纽鳃樽东方亚种高丰度水域,能够较为准确地反映黑潮入侵陆架水团和沿岸水交汇的位置。     

东海水母类丰度的动力学特征

本文根据1997-2000年东海23°30′-33°N、118°30′-128°E海域4个季节海洋调查资料,探讨了东海水母类数量变化特征和相应的动力学。结果表明:水母类是东海浮游动物的第三大类群,其丰度仅次于桡足类和海樽类;其数量有明显的季节变化,春季丰度最高(5·37ind·/m3),秋季次之(2·23ind·/m3),冬季(1·82ind·/m3),夏季最低(0·88ind·/m3);其平面分布特征为近海高于外海;其数量变化首先来自优势种大西洋五角水母(Muggiaeaatlantica)和双生水母(Diphyeschamissonis)的贡献,前者是近岸暖温种,后者是近岸暖水种;春季丰度变化与表层和底层盐度二元线性相关,夏季与底层水温相关,秋季与底层盐度相关,冬季与表层盐度相关,4季总丰度与10m层盐度相关。盐度是影响水母类数量变化的主要环境动力学因子,水温是次要因子;水母类高丰度区往往位于台湾暖流与长江径流交汇处偏冲淡水水团一侧。长江冲淡水在不同季节入海后的流向是决定高丰度分布区位置重要的动力学因子。该类浮游动物对沿海海域生物安全、生态安全和环境安全都有重要的影响,引起全球的普遍关注。     

东海近海浮游多毛类数量分布与环境关系

根据2002--2003年在东海近海28°00′N-32°00′N、122°00′N-123°30′E4个季节的海洋调查,探讨了东海近海浮游多毛类总丰度和种类变化的季节特征以及这些变化与水团的关系、优势种的数量变动和对多毛类的贡献和优势种的环境适应等,并与东海外海多毛类的生态特征做了比较。结果表明：该海域浮游多毛类总丰度具有明显的季节变化;夏季平均丰度最高（1．30ind·m^-3）,分布范围最广,春季平均丰度最低（0．04ind·m^-3）;调查共发现15种浮游多毛类,盲蚕（Typhloscolex muelleri）、明蚕（Vanadis sp．）和泳蚕（Plotohelmis capitata）是优势种,其中盲蚕是四季的优势种,夏季和冬季的优势度较高分别为0．16和0．1,明蚕仅是夏季的优势种,泳蚕仅是秋季的优势种;盲蚕在春、冬季贡献率较高,分别为1和0．94,占绝对优势,更适应暖水广盐的环境;东海近海浮游多毛类具有种类数变化大,种类组成多样的特点;不同季节数量变化较大,平面分布格局各不相同。     

东海浮游枝角类生态学研究

根据1997~2000年在东海23°30′~33°00′N、118°30′~128°00′E海域4个季节的海洋调查资料,探讨了东海浮游枝角类生态特征、数量变化和相应的动力学。结果表明,枝角类丰度夏季最高(17.16 ind.(100 m3)-1),秋季(14.68 ind.(100 m3)-1)次之,春季(0.63 ind.(100 m3)-1)较低,冬季该类未出现。春、夏、秋季的肥胖三角氵蚤(Evadne tergestina)和夏季的鸟喙尖头氵蚤(Penilia avirostris)是影响枝角类数量分布的主要种;春、夏、秋季枝角类总丰度与盐度呈负线性相关关系,与水温相关关系不显著。枝角类较高丰度区常位于沿岸淡水水团与其他水团交汇处偏沿岸水一侧。其数量变化动力主要来自沿岸冲淡水势力,特别是长江冲淡水势力的消长。枝角类在东海出现率较低,有一定的集群性,较高丰度的分布基本上局限在冲淡水势力影响范围内,其高丰度的水域是沿岸水团的一个重要标志。     

丰水期长江感潮河口段网采浮游植物的分布与长期变化

于2009年6、8月对长江口门至江阴的河口段浮游植物进行了拖网采集,共检出浮游植物6门99属239种。其中:硅藻123种,甲藻19种,绿藻和蓝藻各42种,裸藻9种,黄藻4种。河口段网采浮游植物丰度以蓝藻占绝对优势,硅藻次之,两者合计在群落中的比例超过了95%。优势种也主要以蓝藻(水华鱼腥藻Anabaena flos-aquae、柔软腔球藻Coelosphaerium kuetzingiarum、微囊藻Microcystis spp.、颤藻Oscillatoria spp.和席藻Phorimidium spp.)构成,硅藻仅有2种(骨条藻Skeletonema spp.和颗粒直链藻Aulacoseira granulata)。口门内盐度均<0.5,群落基本以淡水类群为主,口门附近则以半咸水类群为主,海水类群主要位于口门外(盐度>13)。随着水温和营养盐水平的升高,8月浮游植物平均丰度(347.75×10⁴ 个/m³)明显高于6月(204.19×10⁴ 个/m³)。根据多维尺度和相似性分析,丰水期长江河口段浮游植物群落组成与分布存在显著(P<0.01)的时空差异。对比20世纪80年代以来的历史资料发现,长江口门内网采浮游植物丰度显著升高,且优势种也从硅藻(骨条藻、直链藻和圆筛藻)转变为蓝藻(颤藻、鱼腥藻和微囊藻)。     

长江河口浮游动物的种类组成、群落结构及多样性

于1999年枯水期(2—3月份)、丰水期(8月份)、2000年枯水期(2—3月份)对长江河口浮游动物采样调查,研究了长江河口浮游动物的种类组成、群落结构及多样性并初步探讨了三峡工程对长江河口浮游动物的影响及长江河口水环境的生物监测。调查共发现浮游动物87种,甲壳动物占绝对优势,共59种。在所有浮游动物中挠足类31种。其次为水母类,有9种,此外,枝角类、毛颚类各8种。3次采样浮游动物的优势种主要有河口半咸水种和近岸低盐种类如华哲水蚤(Sinocalanus sinensis)、火腿许水蚤(Schmackeria poplesia)、虫肢歪水蚤(Tortanus vermiculus),真刺唇角水蚤(Labidocera euchaeta)等,还有长江径流带到河口的淡水种如近领剑水蚤（Cyclops vicinus vicinus)、英勇剑水蚤（Cyclops strenuus）、透明溞（Daphnia hyalina)等。一些浮游动物可作为水系指示种,其分布、数量反映了不同水系分布变化,长江河口浮游动物有;类水系指示种。通过对长江河口浮游动物群落聚类分析发现。1999、2000年枯水期浮游动物群落结构相似。可分为河口类群、近岸类群和近外海类群。1999年丰水期只形成近岸和近外海类群。浮游动物种类数由口门内向口门外方向有逐渐增加的趋势。浮游动物种类数由北向南变化趋势一致。大潮与小潮、涨憩与落强等潮汐作用对浮游动物影响往往因采样时间与区域等的不同而不同。对长江河口3次采样的物种多样性指数和均匀度指数进行了计算,结果表明：浮游动物多样性指数1999年枯水期最低,1999年丰水期最高。     

东海水螅水母环境适应与生态类群

根据1997—2000年东海23°30′—33°00′ N、118°30′—128°00′ E海域4个季节海洋调查资料,依据丰度和同步表层温、盐度数据,采用曲线拟合构造了数学模型,并结合地理分布分析对东海水螅水母最适温度、最适盐度和生态类群进行了研究.结果表明：东海水螅水母适温环境多样,最适温度低于20 ℃的有15种,在20 ℃～22.5 ℃之间的有8种,在22.5 ℃～25 ℃之间的有12种,超过25 ℃的有17种;大多数物种（32种）最适盐度为32～34,大于34的有13种,在30～32之间的有6种,低于30的仅出现2种.水螅水母大多数物种生存的盐度区间较窄,它们的数量和分布范围有限.嵊山秀氏水母等2种属暖温带近海种,八囊摇篮水母等13种属暖温带外海种,宽外肋水母等8种属亚热带近海种,半口壮丽水母等5种具有热带大洋种特征,四叶小舌水母等25种属亚热带外海种.东海水螅水母的许多物种可作为东海水团重要的指示种.     

鄱阳湖发现鲻北大核心CSCD

鲻(Mugil cephalus)隶属于鲻形目(Mugiliformes)鲻科(Mugilidae)鲻属,为浅海中上层鱼类,广泛分布于太平洋、印度洋、大西洋、地中海、黑海等温带和热带近岸海区,我国沿海均有分布。鲻对盐度的适应广,在淡水、咸淡水和盐度高达40的海水中都能生活,适温范围3~35℃,喜暖水(区又君2015)。鲻个体大、生长快、食物链短,是我国沿海经济鱼种。鲻可栖息在近岸浅海、河口的咸淡水交界处及港湾内,在长江主要分布于其河口附近(毛节荣1991,倪勇等2006)。     

Role for dopamine in malonate-induced damage in vivo in striatum and in vitro in mesencephalic cultures

Defects in mitochondrial energy metabolism have been implicated in the pathology of several neurodegenerative disorders. In addition, the reactive metabolites generated from the metabolism and oxidation of the neurotransmitter dopamine (DA) are thought to contribute to the damage to neurons of the basal ganglia. We have previously demonstrated that infusions of the metabolic inhibitor malonate into the striata of mice or rats produce degeneration of DA nerve terminals. In the present studies, we demonstrate that an intrastriatal infusion of malonate induces a substantial increase in DA efflux in awake, behaving mice as measured by in vivo microdialysis. Furthermore, pretreatment of mice with tetrabenazine (TBZ) or the TBZ analogue Ro 4-1284 (Ro-4), compounds that reversibly inhibit the vesicular storage of DA, attenuates the malonate-induced DA efflux as well as the damage to DA nerve terminals. Consistent with these findings, the damage to both DA and GABA neurons in mesencephalic cultures by malonate exposure was attenuated by pretreatment with TBZ or Ro-4. Treatment with these compounds did not affect the formation of free radicals or the inhibition of oxidative phosphorylation resulting from malonate exposure alone. Our data suggest that DA plays an important role in the neurotoxicity produced by malonate. These findings provide direct evidence that inhibition of succinate dehydrogenase causes an increase in extracellular DA levels and indicate that bioenergetic defects may contribute to the pathogenesis of chronic neurodegenerative diseases through a mechanism involving DA.     

Changes in lactate dehydrogenase activity in chicken tissues in hyperthyreosis in ontogenesis

The lactate dehydrogenase activity in reactions of lactate oxidation and synthesis was studied in subfractions of the chicken brain, heart and liver at the embryonal, early postembryonal and adult stages of development after thyroxine administration. It has been shown that during embryogenesis thyroxine predominantly enhanced the rate of lactate oxidation in the mitochondrial tissues. A marked increase in the lactate synthesis was found in cytoplasm of the adult chicken tissues. Specificity of enzyme activity alterations was detected in the chicken brain during ontogenesis after thyroxine administration.     

Scurvy in capybaras bred in captivity in Argentine

In order to determine if the absence of vitamin C in the diet of capybaras (Hydrochoerus hydrochaeris) causes scurvy, a group of seven young individuals were fed food pellets without ascorbic acid, while another group of eight individuals received the same food with 1 g of ascorbic acid per animal per day. Animals in the first group developed signs of scurvy-like gingivitis, breaking of the incisors and death of one animal. Clinical signs appeared between 25 and 104 days from the beginning of the trial in all individuals. Growth rates of individuals deprived of vitamin C was considerably less than those observed in the control group. Deficiency of ascorbic acid had a severe effect on reproduction of another population of captive capybaras. We found that the decrease in ascorbic acid content in the diet affected pregnancy, especially during the first stages. The results obtained suggest that it is necessary to supply a suitable quantity of vitamin C in the diet of this species in captivity.     

SSTR5 ablation in islet results in alterations in glucose homeostasis in mice

Somatostatin (SST) peptide is a potent inhibitor of insulin secretion and its effect is mediated via somatostatin receptor 5 (SSTR5) in the endocrine pancreas. To investigate the consequences of gene ablation of SSTR5 in the mouse pancreas, we have generated a mouse model in which the SSTR5 gene was specifically knocked down in the pancreatic beta cells (betaSSTR5Kd) using the Cre-lox system. Immunohistochemistry analysis showed that SSTR5 gene expression was absent in beta cells at three months of age. At the time of gene ablation, betaSSTR5Kd mice demonstrated glucose intolerance with lack of insulin response and significantly reduced serum insulin levels. Insulin tolerance test demonstrated a significant increase of insulin clearance in vivo at the same age. In vitro studies demonstrated an absence of response to SST-28 stimulation in the betaSSTR5Kd mouse islet, which was associated with a significantly reduced SST expression level in betaSSTR5Kd mice pancreata. In addition, betaSSTR5Kd mice had significantly reduced serum glucose levels and increased serum insulin levels at 12 months of age. Glucose tolerance test at an older age also indicated a persistently higher insulin level in betaSSTR5Kd mice. Further studies of betaSSTR5Kd mice had revealed elevated serum C-peptide levels at both 3 and 12 months of age, suggesting that these mice are capable of producing and releasing insulin to the periphery. These results support the hypothesis that SSTR5 plays a pivotal role in the regulation of insulin secretion in the mouse pancreas.