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1.
长寿湖浮游植物功能群季节变化及影响因子   总被引:2,自引:0,他引:2  
研究浮游植物功能群落季节变化,探究其与环境因子之间的关系,揭示不同环境因子影响下浮游植物群落结构与演替规律,为长寿湖的保护、利用和管理提供科学依据。2013年3月至2014年2月对长寿湖7个采样点进行逐月调查,优势度≥0.02的物种为优势种,采样点相对生物量20%的功能群为重要功能群,运用多元分析方法对浮游植物功能群组成、季节变化及其与环境因子的关系进行了分析。结果表明:长寿湖有浮游植物7门11纲18目29科54属83种,其中45种浮游植物归入14个功能群,优势功能群为D、J、LO、MP、P、S1、SN、X2和Y。不同季节优势功能群存在明显差异,变化规律为:S1+Y→S1+SN→Y+J→D+Y,功能群Y是长寿湖代表性功能群,反映了水环境富营养化的特征。冗余分析(RDA)表明,长寿湖浮游植物功能群季节变化受环境因子影响较为明显,整体上,透明度(SD)、水温(WT)、电导率(EC)、光照强度(LUX)、溶解氧(DO)和总氮(TN)是影响长寿湖浮游植物功能群变化的主要环境因子。  相似文献   

2.
为了研究尔王庄水库浮游植物功能群时空分布特征,于2018年3月~12月进行逐月采样。结果显示:调查期间共鉴定浮游植物7门77种,划分了21组浮游植物功能群,以D功能群占绝对优势,代表种属为针杆藻属(Synedra sp.)。常见功能群为C、D、F、J、LO、X1,主要适应中到富营养、洁净、混合水体。浮游植物功能群的季节演替变化明显,夏季和秋季的功能群生物量明显高于春季和冬季,变化特征为春季(C、D、E)-夏季(D、S1、WS)-秋季(D)-冬季(D)。  相似文献   

3.
浮游植物群落结构既可以反映水源水环境质量,也能指示水源生态系统的健康状况。以温州市珊溪水库为例研究从水库丰水期到枯水期水文情势变化过程中浮游植物群落分布特征的变化及其影响因子。基于功能群分类体系确定浮游植物优势功能群,应用Pearson相关分析和冗余分析法研究水库不同生态区中浮游植物功能群、Margalef丰富度指数和生态健康指数Q的分布特征,进一步采用冗余分析识别不同水文情势期下其主要环境驱动因子进行,最终探讨了浮游植物优势功能群演替、生长策略模式及其与驱动因子的互指示关系。结果表明:(1)珊溪水库浮游植物可分为19个功能群,功能群个数丰水期最高,枯水期最低,其中M、MP、C、P为4个优势功能群;(2)珊溪水库浮游植物优势功能群在不同水文期的演替特征为MP→M→C(丰水期→平水期→枯水期);(3)生态健康Q 指数范围为2.66~3.26,水体整体情况为中营养范围,其中丰水期和平水期的Q指数较枯水期更低,表明此时珊溪水库营养化污染问题更为严重,与功能群分布的动态变化特征一致;(4)氧化还原电位、高锰酸盐指数和水温为影响珊溪水库浮游植物优势功能群和相关生物指标时空分布变化的主要驱动因子;(5)浮游植物优势功能群与关键环境因子之间存在明显的对应关系,依据优势功能群适宜生境特点及生长策略可以相互指示。  相似文献   

4.
2015年夏季(8月)在济南地区不同类型水体中采样调查,分析了浮游植物功能类群的组成及其与环境因子的关系。结果表明:夏季在济南地区共采集到13类浮游植物功能群,分别为TB、P、B、C、MP、D、W_1、W_2、Y、X_1、X_2、J和F。其中,MP类物种和密度最高。典范对应分析得出,电导率和NH_3-N对W_1类和B类起主要作用,而影响MP和C类的主要因素是硬度。  相似文献   

5.
洪潮江水库是广西南部一座中型水库,本研究于2018年夏(6月)和2019年冬(1月)对洪潮江水库9个采样点的理化因子和浮游植物功能类群进行了研究。洪潮江水库较低的磷含量和高达200的氮磷比表明该水库为磷限制水体,该水库夏季均温为30.5℃,冬季均温为13.6℃,夏季硝态氮、氨氮、溶氧含量和透明显著低于冬季。洪潮江水库在夏冬两个季节中共检测出 7 门59属,分别归属于17个功能群, 包含拟柱孢藻Sn功能群是洪潮江水库的主要优势种,洪潮江水库较高的温度,磷限制的环境以及较高的浑浊度是促进拟柱孢藻占据优势,并在夏季产生水华的主要原因。功能群Lm微囊藻在部分采样点与拟柱孢藻共同占据优势,表明拟柱孢藻和微囊藻之间存在较大种间竞争。其它优势类群包括以多甲藻为主的功能群Lo、以鱼腥藻为主的H2类群、包含直链藻的P类群、包含隐藻属的Y类群均属于中-富营养到富营养的种类。皮尔森相关系数和RDA分析表明温度、浑浊度、高锰酸钾指数是促进大部分功能类群的主要环境因子,而与TN、氨氮以及溶氧呈负相关。根据浮游植物种类组成可以判断洪潮江水库为富营养化,而拟柱孢藻和微囊藻为优势的具有产毒潜力的蓝藻将会对水库水质安全产生威胁。  相似文献   

6.
于2019年春夏秋三季对金沙江中下游(自流水体和库区)浮游植物群落组成、功能群以及多样性指数进行调查,并分析了浮游植物功能群与环境因子的关系。结果表明:金沙江中下游流域共鉴定出浮游植物8门32科54属96种,以硅藻门(39.58%)为主,其次是绿藻门(31.25%)。自流水体与库区在浮游植物群落组成上差异不显著;Shannon-Wiener指数、Margalef指数和Pielou指数平均值分别为2.42、1.81和0.92,单因素方差分析表明三项多样性指数在各采样点之间、各季节之间无显著差异;对浮游植物功能群进行划分,共划分出24个功能群,其中8个(D、P、X1、J、C、LM、F、G)为该区域的优势功能群。D和P功能群是金沙江中下游各采样点常年共有的优势功能群。Pearson相关性分析和冗余分析(RDA)结果显示,温度、浊度、海拔、氨氮和硝态氮是影响金沙江中下游流域浮游植物功能群分布格局的主要因子。本研究可为金沙江干流水生生物保护、生态修复以及水质评价提供科学依据和理论基础。  相似文献   

7.
珠江三角洲地区精养淡水鱼塘浮游植物功能群特征   总被引:2,自引:1,他引:1  
分别于养殖前期(5月)、中期(9月)和后期(12月),对珠江三角洲地区主养草鱼(Ctenopharyngodon idellus)、大口黑鲈(Micropterus salmoides)、云斑尖塘鳢(Oxyeleotris marmoratus)和乌鳢(Channa argus)4个品种池塘中的浮游植物功能群进行研究。结果表明,采样池塘浮游植物丰度、物种多样性指数较高,密度均值达1.32×10~8 cell/L,最大值为3.00×10~8 cell/L,生物量均值为168.17 mg/L,最大值为345.41 mg/L;共鉴定到196种(含变种变型)藻类,分属于绿藻(91种)、裸藻(40种)、硅藻(27种)、蓝藻(23种)、甲藻(7种)、隐藻(4种)、黄藻(3种)、金藻(1种)等8大藻门;采样池塘藻类可划分出A、B、C、D、F、G、G_2、H1、J、K、L_1、L_M、L_0、M、MP、N、P、S1、S2、T、T_D、W1、W2、W_S、X1、X2、X_(Ph)、Y等28个功能群;频率分析发现C、F、J、MP、N、P、W1、X2、Y、K、L0、M、W2等主要优势功能群在精养池塘中出现频率高,生物量比重大,说明池塘浮游植物群落稳定,整个养殖过程水体的生态功能比较单一;对环境因子与主要优势功能群进行冗余分析(RDA),得到池塘浮游植物功能群分布状况的首要影响因素是有机质含量(COD_(Mn)),其次为营养物质含量水平(TP和N:P),最后为水体物理环境,包括透明度(SD)、pH、溶解氧(DO)、总可溶性固体(TDS)和水温(WT)。研究发现,池塘水体浮游植物功能群数养殖中期多于前期和末期,并在养殖中期水体交换量大的大口黑鲈和云斑尖塘鳢池塘较为突出,表明在高密度精养池塘中,进行充足的水体交换是高温时期防控水质恶化的重要措施。基于传统的物种多样性指数方法,判定池塘水质状况为洁净,但以浮游植物功能群生境特征判定水体污染严重,且与水体理化环境测定结果和现场水体表观相符,说明功能群比多样性指数能更好地反应池塘水质的真实状况。  相似文献   

8.
云贵高原渔洞水库浮游植物群落结构及季节演替   总被引:1,自引:0,他引:1  
2009年11月至2010年10月对云南省昭通市渔洞水库浮游植物群落结构及季节演替进行了周年调查。结果表明,常见浮游植物共7门、96种;其中,绿藻门52种,硅藻门22种,蓝藻门13种,甲藻门3种,隐藻门、金藻门和裸藻门各2种。浮游植物生物量的季节变化表现为春、冬季较低,夏、秋季较高,且在8月达到浮游植物生物量(以细胞数计)最高峰值1.19×107个/L,叶绿素a最高峰值可达28.6μg/L。渔洞水库全年以硅藻门的钝脆杆藻(Fragilaria capucina)和尖针杆藻(Synedra acus)为主要优势种;另外,3-5月甲藻门的角甲藻(Ceratium hirundinel-la)及金藻门的分歧锥囊藻(Dinobryon divergens)是显著的亚优势种。将周年调查结果进行RDA分析,可见影响浮游植物季节演替的主要因素是水温,水温变化与浮游植物生物量成极显著正相关关系(r=0.762,P<0.01);与浮游植物种类数成极显著负相关关系(r=-0.721,P<0.01),与浮游植物生物多样性成显著负相关关系(r=-0.638,P<0.05)。  相似文献   

9.
为了研究汤浦水库浮游植物群落结构季节演替及水质状况,于2010年5、8、11月及2011年2月连续4个季节分别对其浮游植物、水文特征和理化因子进行调查分析.结果表明,浮游植物有7门、58属、105种,主要由绿藻、硅藻和蓝藻组成,其物种数季节变化为:夏>秋>冬>春.各样点物种数呈现出由河流区向湖泊区递减的变化趋势.浮游植物丰度变幅较大,在3.27×106~128.90×106个/L,其中冬季丰度最低,春季最高.春季浮游植物主要由硅藻和蓝藻组成,夏季主要由蓝藻和绿藻组成,秋季为隐藻和硅藻,冬季主要由硅藻组成.浮游植物丰度及其多样性指数均表明春季水质最差,且暴发藻类水华,其中微型硅藻链状弯壳藻(Achnanthidium catenatum)为春季水华的绝对优势种.水华暴发可能受降水、水库调度、营养盐等因素的综合影响所致.  相似文献   

10.
2018年春季(5月),在呼伦湖及其周围水域不同类型水体中设置28个采样点(呼伦湖湖域17个,周围河流流域11个)调查了浮游植物种类和数量,监测了水环境因子,探讨了呼伦湖及其周围水域春季浮游植物功能群及其与环境因子之间的关系。结果表明:春季在呼伦湖及其周围水域中共鉴定出7门80种浮游植物,其中呼伦湖中以绿藻门为主,而周围河流流域则以硅藻门为主。调查区域浮游植物共分为20个功能群,其中C、X2、J和D为重要功能群。Pearson线性相关分析和RDA分析均表明:化学需氧量和电导率是影响呼伦湖及其周围水域浮游植物功能群最主要的水环境因子,功能群C和D同化学需氧量和电导率显著负相关,功能群J同化学需氧量和电导率显著正相关,而功能群X2受水温和溶解氧影响较大,同水温和溶解氧显著正相关。用GB3838-2002评价标准评估各采样点的总氮、总磷及化学需氧量结果表明,呼伦湖内(M9、M16)水质极差,总氮、总磷和化学耗氧量均超过国家V类水标准(2mg/L、0.2mg/L、40mg/L);呼伦湖内西岸(M10~M13)、湖中心(M22~M24)以及周围水域的呼和诺尔(M3)、乌兰诺尔(M27)水中总磷和化学需氧量污染极为严重。结果发现,周围河流水质明显优于呼伦湖内水质。  相似文献   

11.
The environmental processes associated with variability in the catch rates of bigeye tuna in the Atlantic Ocean are largely unexplored. This study used generalized additive models (GAMs) fitted to Taiwanese longline fishery data from 1990 to 2009 and investigated the association between environmental variables and catch rates to identify the processes influencing bigeye tuna distribution in the Atlantic Ocean. The present findings reveal that the year (temporal factor), latitude and longitude (spatial factors), and major regular longline target species of albacore catches are significant for the standardization of bigeye tuna catch rates in the Atlantic Ocean. The standardized catch rates and distribution of bigeye tuna were found to be related to environmental and climatic variation. The model selection processes showed that the selected GAMs explained 70% of the cumulative deviance in the entire Atlantic Ocean. Regarding environmental factors, the depth of the 20 degree isotherm (D20) substantially contributed to the explained deviance; other important factors were sea surface temperature (SST) and sea surface height deviation (SSHD). The potential fishing grounds were observed with SSTs of 22–28°C, a D20 shallower than 150 m and negative SSHDs in the Atlantic Ocean. The higher predicted catch rates were increased in the positive northern tropical Atlantic and negative North Atlantic Oscillation events with a higher SST and shallow D20, suggesting that climatic oscillations affect the population abundance and distribution of bigeye tuna.  相似文献   

12.
Previously, we reported 10 PEGE types of 85 tilapia Streptococcus agalactiae(GBS), which shifted from Streptococcus iniae in China, by using PEGE method. Presently, larger and more representative tilapia GBS were isolated, for the ?rst time in China, to characterize their serotypes and genetic diversities more precisely than had done before. 168 GBS strains were distributed in ?ve provinces of China, in which Guangdong, Guangxi and Hainan were the major ones, holding36.9%(62/168), 37.5%(63/168) and 19.6%(33/168), respectively. Serotypes, Ia, Ib and III, were observed in these strains and the most predominant one was Ia(95.2%), which mainly distributed in Guangdong, Guangxi and Hainan. Ia initially occurred in 2009, it shoot up to 32.1% in 2010,but decreased to 16.1% in 2011 before went up to 45.2% in 2012. Ib sporadically occurred during2007–2011, III onlyoccurred in 2012. 14 different PFGE types, including 4 new types(N, O,P and Q), were observed, in which B, D, F and G were the predominant types, holding 83.9%(141/168) of the total GBS strains. Ia corresponded to 11 PFGE types(A–H, N–P), in which type D predominated(51%). Ib represented 3 genotypes(I, J and Q) and III harbored only 2genotypes(N and F). Type N and Fsynchronously presented in Ia and III. In summary, the genetic diversity of tilapia GBS varied by serotypes and changed with geographical locations and years.Although Iastillpredominated, new rareserotypeIII alreadyoccurred in China.  相似文献   

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In this experiment, a feeding trial was performed to determine the effects of fructooligosaccharide (FOS) on growth performance, digestive enzyme activity and immune response of Japanese sea bass, Lateolabrax japonicus juveniles (initial weight 38.3 ± 0.5 g), and the fish were examined following feeding with six levels of FOS (0, 0.5, 1, 2, 4 and 6 g/kg) for 28 days. Significant enhancement of weight gain (WG) and specific growth rate (SGR) was found in fish fed 1 g/kg FOS incorporated diets (p < .05), while the feed conversion ratio (FCR) in the 1, 2 g/kg FOS groups reduced significantly compared with the control (p < .05). Besides, the crude lipid in the 4, 6 g/kg FOS groups increased significantly compared with the control (p < .05). On the other hand, the erepsin and lipase activities significantly elevated in intestine of fish fed 2 g/kg FOS (p < .05) and the lysozyme activity in serum of fish fed 2 g/kg FOS were significantly higher than that in the control (p < .05). Moreover, the alkaline phosphatase activities in serum of fish fed 0.5, 1, 2 g/kg FOS were significantly higher than in control (p < .05). Regression analysis showed that the relationships between dietary FOS levels and either SGR, FCR, erepsin or lysozyme activities were best expressed by regression equations, and the optimal inclusion levels are 1.37, 1.80, 3.06, 3.11, 1.93 and 1.80 g/kg for SGR, FCR, erepsin, lipase, lysozyme and total superoxide dismutase activities, respectively. Overall, this study revealed that FOS incorporated diets could beneficial for L. japonicus culture in terms of increasing the growth, digestion and immune activities. Under the present experimental condition, the optimal supplementary level of FOS in the diet of L. japonicus is 1–3 g/kg.  相似文献   

16.
Growth hormone (GH) and reproduction: a review   总被引:5,自引:0,他引:5  
Interaction between growth and reproduction occurs in many vertebrates and is particularly obvious at certain stages of the life cycle in fish. Endocrine interactions between the gonadotropic axis and the somatotropic axis are described, the potential role of GH being emphasised. A comparative analysis of these phenomena in mammals, amphibians and fish, suggests a specific role of GH in the physiology of puberty, gametogenesis and fertility. It also shows the original contribution made by studies on the fish model in this field of investigations.  相似文献   

17.
Protein and amino acid composition of the mantle of juvenile O ctopus vulgaris (Cuvier, 1797) during fasting for 27 days were determined. Average protein content of octopus mantle was of 711.19 ± 46.80 g kg?1 DW, and it decreased with increasing fasting days. The non‐essential amino acids content was higher (486.18 ± 11.08 g kg?1 protein) than essential amino acids (425.82 ± 9.15 g kg?1 protein) at the start of the experiment (unstarved animals). The results suggest that the amino acid profile of the mantle where the most abundant amino acids are Arg, His, Lys, Gly, Leu and Pro could indicate a prolonged fasting condition (>20 days) or poor nutrition of O . vulgaris. This study supports the idea of using mantle for metabolic needs of starved O . vulgaris suggesting that the degradation pathway of amino acids to pyruvate and tricarboxylic acid cycle intermediates was favoured contrary to the degradation pathway of ketogenic amino acids. Special considerations should be taken concerning Thr, Ile, Ser, Ala, Asx (Asp, Asn), Glx (Glu, Gln) (because of their fast intake) and Lys and His (due to their stable contents) during a prolonged period of fasting.  相似文献   

18.
Two gonadotropins (GtH; Qa and Qb) were purified by gel filtration and ion exchange chromatography from the pituitaries of Indian walking catfish (Clarias batrachus). The presence of GtH during purification was assessed by in vitro oocyte maturation and in vivo steroidogenic activity, and their identities were determined by elution profiles, molecular weight, biological activities and yield. The molecular weights of Qa and Qb were 37 and 42 kDa, respectively, and composed of distinct subunits (Qa: 20 and 14 kDa and Qb: 26 and 18 kDa). Polyclonal antibodies raised against Qa immunostained Qa, Qb and pituitary GtH cells. A competitive Qa‐ELISA was developed whose sensitivity was 6.25 ng mL?1 (1.25 ng well?1) with intra‐ (3.5%) and inter‐ (12.4%) assay coefficients of variation. Displacement curves parallel to the standard were obtained with plasma and pituitary extracts of catfish, Qb and carp GtHII. The assay was validated by measuring the plasma Qa levels after LHRH treatment and in relation to ovarian growth in the female catfish during different reproductive phases. Based on the results, Qa and Qb corresponded to fish LH and FSH respectively. The findings will increase the knowledge of the mechanisms controlling fish reproduction and identification of sensitive phases in fish in captivity for hormonal manipulation.  相似文献   

19.
Tetrahymena is a protozoan parasite, which infects guppy, Poecilia reticulata Peters, and causes substantial economical losses in commercial farms worldwide. Studies of guppy infected by Tetrahymena require standardized infection protocols. The LD50 for Tetrahymena infection of guppies by intraperitoneal (IP) injection was calibrated, and the level obtained was 946 parasites per fish. Guppy infection with Tetrahymena by immersion, imitating the natural route of infection via the integument, was studied under normal or stress conditions. Exposure to cold and netting (CNI) and to cold only (CI) followed by immersion exposure to 10 000 Tetrahymena per mL resulted in 22.5% and 19.2% mortality, respectively, as compared to 14.2% and 10% in groups that were netted only (NI) or non‐stressed (I). Histopathology revealed that immersion infection resulted in a systemic infection. Lysozyme levels, measured 3 weeks after infection, were significantly higher in the CNI group (288 μg per mg protein) compared with CI‐, NI‐ and I‐treated groups (94.5, 64 and 62.3 μg mg?1, respectively). There was no evident parasite immobilization activity in body homogenates, suggesting no development of acquired immunity. Re‐infection by IP injection revealed no increase in protection in any of the treatment groups, mortality range of 56.3–75%, higher than in the non‐exposed control (40.6% mortality).  相似文献   

20.
The purpose of this work was to evaluate the suitability of a method based on the presence of two restriction sites (for Hae III and Hindf I) in the mitochondrial NADH dehydrogenase subunit 5 (mt ND5) gene to identify Scomber species. The evaluation was performed on 144 reference and market samples by sequencing of the entire 505-bp fragment of the mt ND5 gene and of a 464-bp fragment of the Kocher fragment of the cytochrome b gene (mt Cytb). Sequence analysis of any of the two fragments allows the identification of each of the four Scomber species, but S. japonicus and S. colias had the same restriction sites at the ND5 amplicon and would not have been differentiated by this analysis. Similarly, loss of the Hae III site in some S. scombrus individuals would have misidentified them as not being Scomber. All the market products were correctly labeled except one acquired in Spain labeled as originating in the Atlantic and containing S. japonicus.  相似文献   

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