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为了解洞庭湖浮游植物的时空分布特征及原因,在2016年对洞庭湖浮游植物开展了季度调查。结果表明洞庭湖浮游植物样品中共检出6门53属,其中蓝藻门4属、绿藻门19属、硅藻门21属、隐藻门2属、裸藻门4属、甲藻门3属。洞庭湖浮游植物的平均密度为28.6×104cells/L,其中硅藻门最为丰富,占总密度的43.1%,其次为蓝藻门占23.4%、绿藻门占18.9%、隐藻门占8.8%、裸藻门占3.9%、甲藻门占1.9%。空间分布上,东洞庭湖浮游植物密度最高,其次为南洞庭湖、洞庭湖出口、入湖口和西洞庭湖。时间分布上,6月份浮游植物密度最高,其次为9月、3月和12月份。洞庭湖全湖综合营养状态指数为49.9,为中营养水平,其中东洞庭湖出现了轻度富营养化,尤其是大小西湖在夏秋季节有水华爆发的风险。典范对应分析(CCA)分析表明总磷和透明度是影响洞庭湖藻类分布的主要影响因素。 相似文献
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江苏横山水库浮游植物群落结构的动态变化 总被引：2，自引：0，他引：2
研究横山水库浮游植物群落的动态变化特征和综合分析水质,为库区的水资源保护和开发利用提供参考依据。2014年7月至2015年6月,设置5个采样点,每月上旬上午9时左右、天气状况良好时采水样1次。共采集鉴定浮游植物7门63属147种(包含变种及变型),绿藻门28属63种、硅藻门16属46种、蓝藻门10属23种、甲藻门3属6种、裸藻门3属3种、隐藻门2属3种、金藻门1属3种,浮游植物的种类组成为绿藻-硅藻-蓝藻型。浮游植物密度2.3×106~8.0×106个/L、平均4.2×106个/L,硅藻门、绿藻门和蓝藻门密度占比分别为57.3%、29.8%和8.4%。浮游植物的多样性指数H'变化范围为1.52~3.67,平均2.48;均匀度指数J 0.53~0.86、平均0.71;丰富度指数d 0.83~3.32、平均2.05。浮游植物主要优势种为绿藻门的美丽鼓藻(Cosmariumformosulum),硅藻门的变异直链藻(Melosiravarians)、颗粒直链藻(Melosira granulate)、尖针杆藻(Synedraacus)和肘状针杆藻(Synedra ulna)等。相关性分析表明,游植物密度与总磷、水温、透明度呈正相关关系,与溶解氧呈负相关关系,与总氮没有相关关系。硝酸盐和溶解氧对浮游植物密度有显著影响,亚硝酸盐氮、氨氮、CODMn、浊度、p H、UV254的水平变化和浮游植物密度没有相关性。根据浮游植物多样性分析以及富营养化指数值TLI(∑)评价,横山水库水质属于轻度富营养状态。 相似文献
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2006年10月对升金湖中的浮游藻类进行了调查,分析了浮游藻类分布规律及优势种的组成、浮游藻类多样性分布和浮游植物与环境因子的关系;利用多种多样性评价指数对水体的污染情况进行了评价.结果表明,升金湖有浮游藻类8门、101属、358种.浮游藻类的密度差异明显,介于81.7×104～6 427×104个/L,主要由蓝藻、绿藻、硅藻、甲藻、裸藻、隐藻、黄藻和金藻等组成,以蓝藻门的鞘丝藻、平裂藻和鱼腥藻,硅藻门的小环藻、针杆藻和直链藻,绿藻门的栅藻和盘星藻为优势种.各种评价指数显示,水体大部分区域的污染程度较为严重,整个湖泊属富营养化范畴. 相似文献
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为探究广东韩江潮州市饮用水源保护江段浮游植物群落结构特征及水质富营养化状况,于2019年2月至2020年1月在潮州段设立4个采样点,进行浮游植物调查和水质监测。结果表明,韩江潮州共鉴定出浮游植物8门103属290种,其中绿藻门42属99种,硅藻门21属87种,蓝藻门24属70种。全年有9个月的种类组成以硅藻门为绝对优势种,绿藻门仅在6、9、10月种类数多于硅藻门,表明该江段浮游植物组成为硅藻-绿藻型。浮游植物丰度月变化在0.83×106～1.99×106个/L,月均丰度为0.90×106个/L,全年以硅藻门丰度最高,占47.01%。优势种11种,其中硅藻门5种,隐藻门4种,蓝藻门和裸藻门各1种,颗粒沟链藻(Melosira granulata)是绝对优势种。Shannon-Wiener多样性指数(H)为3.14～5.08,平均值4.40;Pielou均匀度指数(J)为0.69～0.99,平均值0.87;Margalef丰富度指数(D)为2.60～6.85,平均值5.08,表明水质为轻度污染。Cluster聚类和NMDS排... 相似文献
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2021年4月(春季)、7月(夏季)、10月(秋季)和2022年1月(冬季),采用规范方法调查监测和分析受面源污染的浅水铁哈拉泡(46°30’～46°50’N,123°59’～124°15’E)浮游植物群落结构特征及其与水环境因子的关系,并对湖泡水生态保护和治理提出了建议。连环湖铁哈拉泡共鉴定出浮游植物7门66属115种及变种,绿藻门、硅藻门和蓝藻门种类优势占比较大,占总种类数的85.22%。浮游植物的总平均丰度为464.4×104ind./L,总平均生物量为1.533 3 mg/L,绿藻门、硅藻门和蓝藻门丰度和生物量均高于其他门类,其中蓝藻门平均丰度(217.8×104ind./L)和平均生物量(0.489 4 mg/L)均最高。铁哈拉泡浮游植物群落结构季节变化显著,春季蓝藻门、硅藻门和绿藻门为优势门类;夏季和秋季分别为蓝藻门的微囊藻(Microcystis sp.)和硅藻门中的小环藻(Cyclotella sp.)凸显出较大优势;冬季则演变为隐藻门、裸藻门、甲藻门和硅藻门共同占优势的群落结构。TSIM评价结果表明,湖泡营养状态为轻微的富营... 相似文献
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金海水库浮游植物调查及群落结构研究 总被引：2，自引：0，他引：2
为了了解和掌握金海水库水质状况,于2012年6月至2013年5月对金海水库水体理化指标及浮游植物的群落结构进行了逐月监测。采样期间共鉴定出浮游植物7门33属45种,其中绿藻门最多,15属24种;硅藻门次之,8属11种;蓝藻门、裸藻门、甲藻门、隐藻门和金藻门分别鉴定出4属4种、2属2种、2属2种、1属1种、1属1种。金海水库浮游植物数量变化范围20.1×104~335×104个/L,夏季最多,春季最少。浮游植物数量与环境因子相关性分析表明,水体中浮游植物数量主要受水温以及总磷浓度影响。优势度分析表明,金海水库浮游植物优势种有小球藻、肥壮蹄形藻、中型脆杆藻、微小色球藻等31种。金海水库浮游植物多样性指数和均匀度指数分别变化在1.29~3.52和0.38~0.82。金海水库水体浮游植物群落结构较为稳定,整体上以绿藻-硅藻型为主。金海水库水质总体为轻度污染。 相似文献
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包头南海湖非冰封期浮游植物的时空动态特征 总被引：1，自引：0，他引：1
为了解包头南海湖浮游植物群落非冰封期的时空动态特征,2017年5-10月,在南海湖设置了12个监测站位,监测浮游植物时空变化,并同步监测水环境因子。结果表明,南海湖12个站位共鉴定出浮游植物146种(含变种);其中,绿藻门(Chlorophyta)59种,蓝藻门(Cyanophyta)31种,硅藻门(Bacillariophyta)37种,裸藻门(Euglenophyta)9种,金藻门(Chrysophyta)5种,黄藻门(Xanthophyta)3种,隐藻门(Cryptophyta)2种。浮游植物密度为23.35×10~6～115.59×10~6个/L;优势度分析表明,5-6月主要以绿藻占优势,优势种为四尾栅藻(Scenedesmus quadricauda)和螺旋弓形藻(Schroederia spiralis);7-9月主要以蓝藻占优势,优势种为微小平裂藻(Merismopedia tenuissima)和水花束丝藻(Aphanizomenon flosaquae);10月以绿藻和硅藻占优势,优势种为四尾栅藻和近缘针杆藻(Synedra affinis)。空间上呈现出沿进水口向湖心区逐渐递增的趋势,湖心区整体密度较高,而排污口和芦苇区处密度相对较低;冗余分析(RDA)表明,氨氮、化学需氧量、pH、叶绿素-a以及水温是影响浮游植物分布的主要水环境因子,绿藻与总氮关系密切,蓝藻主要受总磷的影响,硅藻受pH影响较大。 相似文献
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新疆乌伦古湖浮游植物种群结构特征 总被引：5，自引：1，他引：4
2007年4月和8月,对新疆乌伦古湖的浮游植物进行了调查研究.结果显示,乌伦古湖浮游植物调查期间经鉴定共计8门172种属.其中以绿藻、硅藻为主,分别占43.0%和29.1%;蓝藻门27种属,占15.7%;裸藻门7种属,占4.1%;甲藻门6种属,占3.5%;金藻门4种属,占2.3%;隐藻门3种属,占1.7%;黄藻门1属,占0.6%.调查期间,乌伦古湖浮游植物密度与生物量均值分别为160.76×104 ind/L和2.0328 mg/L.从优势种、数量和生物量组成结果分析,乌伦古湖浮游植物是以硅藻为优势类群的湖泊,尤其尖针杆藻(Synedra acus),4月在采样点出现频率为80.0%.结合该湖浮游植物的优势种、数量和生物量的检测结果,乌伦古湖应属于贫-中营养型湖泊. 相似文献
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石臼湖江苏段浮游植物群落结构特征及与环境因子的关系 总被引：1，自引：0，他引：1
分析石臼湖江苏段浮游植物群落结构及对环境因子的响应,以期探索浅水型湖泊浮游植物动态变化机制,为石臼湖水域生态环境监测与保护、生物资源调查提供基础数据。2012年10月至2013年8月,在石臼湖江苏段12个采样点进行了4次采样,调查浮游植物的群落结构及水环境因子,并通过冗余分析(RDA)对数据进行直接梯度排序,分析浮游植物群落结构对环境因子的响应。共发现浮游植物79种,隶属于8门53属,绿藻门21属39种,蓝藻门11属13种,硅藻门10属11种1变种1变型,裸藻门4属5种,甲藻门3属4种,隐藻门2属3种,金藻门1属1种,黄藻门1属1种。优势种(属)10种,冬季以对水温和光照有较好适应能力的硅藻为主要优势种群;春季优势种类较丰富,但优势度不高(0.03~0.09);夏、秋季节以小型丝状蓝藻占绝对优势。浮游植物总平均密度为28.93×106个/L,季节差异显著,峰值出现在夏季,冬季最低。多样性分析表明,石臼湖浮游植物的物种组成较丰富,然而种间分布不均,群落结构稳定性较弱。基于CANOCO的多变量分析表明:p H、溶解氧、透明度、氨氮、水温、电导率是影响浮游植物群落结构的主要环境因子。 相似文献
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Association between the interannual variation in the oceanic environment and catch rates of bigeye tuna (Thunnus obesus) in the Atlantic Ocean 
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下载免费PDF全文 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
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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
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Liping Li Rui Wang Wanwen Liang Xi Gan Ting Huang Yan Huang Jian Li Yunliang Shi Honglin Luo Ming Chen 《广西水产科技》2014,(1)
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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Growth hormone (GH) and reproduction: a review 总被引：5，自引：0，他引：5
Florence Le Gac Odile Blaise Alex Fostier Pierre-Yves Le Bail Maurice Loir Brigitte Mourot Claudine Weil 《Fish physiology and biochemistry》1993,11(1-6):219-232
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
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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
17.
Controlled infection of Poecilia reticulata Peters (guppy) with Tetrahymena by immersion and intraperitoneal injection 下载免费PDF全文
下载免费PDF全文 G Sharon M Pimenta‐Leibowitz M C L Vilchis N Isakov D Zilberg 《Journal of fish diseases》2015,38(1):67-74
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
18.
William King V David L. Berlinsky Craig V. Sullivan 《Fish physiology and biochemistry》1995,14(6):489-500
Plasma estradiol-17 (E2), testosterone (T), 17,20-dihydroxy-4-pregnen-3-one (DHP) and 17,20,21-tri-hydroxy-4-pregnen-3-one (20-S) levels were measured by radioimmunoassay (RIA) in white perch (Morone americana) and white bass (M. chrysops) that were induced to undergo final oocyte maturation (FOM) with human chorionic gonadotropin (hCG). Plasma DHP levels increased in females of both species in association with oocyte germinal vesicle migration (GVM) and germinal vesicle breakdown (GVBD) and decreased thereafter. Plasma 20-S levels also increased with oocyte GVM in white bass, but were several-fold lower than DHP levels. Circulating E2 and T levels were greatest during GVM and GVBD in both species and decreased to low levels during oocyte hydration and ovulation. Follicles from white perch and white bass which received a priming injection of hCG in vivo, produced both DHP and 20-S in vitro after exposure to hCG and their oocytes underwent GVBD. Ovarian incubates from unprimed fish of either species produced only E2 and T and their oocytes did not complete GVBD. Oocytes from unprimed bass, but not perch, matured when follicles were exposed to hCG in vitro. Both trilostane and cycloheximide blocked in vitro production of DHP and 20-S and oocyte GVBD by white perch follices. DHP and 20-S were equipotent inducers of FOM in the GVBD bioassay. None of several other structurally-related steroids tested were effective within a physiological range of concentrations. These results indicate a role for DHP and 20-S in the control of FOM in white perch and white bass. 相似文献
19.
Cardiac,ventilatory and metabolic responses of two ecologically dissimilar species of fish to waterborne cyanide 总被引：1，自引：0，他引：1
Changes in heart rate, ventilatory activity and oxygen consumption were determined in trout (Salmo gairdneri) and brown bullhead catfish (Ictalurus nebulosus) during exposure to a steadily increasing concentration of waterborne cyanide selected to produce death in 8–9 hours for each species. The lethal cyanide concentration for the bullheads was an order of magnitude higher than for trout. Trout developed an immediate and gradually increasing bradycardia throughout the exposure period. Cyanide produced tachycardia in the bullhead followed by a gradual onset of bradycardia as the concentration of cyanide was raised. Pericardial injection of atropine (a muscarinic cholinergic antagonist) indicated that bradycardia in the trout was due initially to increased vagal tone but later due to the direct effect of cyanide on the heart. Hyperventilation in the trout persisted throughout the exposure period, although the rate and amplitude fluctuated and was variable between individual fish. During the last hour of exposure (highest cyanide concentration), ventilation was characterized by rapid, shallow breaths followed by a sudden respiratory arrest. The bullheads exhibited hyperventilation during the first 3 hours of exposure followed by a gradual, linear drop in ventilation rate and amplitude until death occurred. Cardiac and ventilatory responses in both species were attributed to stimulation of central and peripheral chemoreceptors by cyanide. Evidence is presented which suggests the initial response in the bullheads was due, at least in part, to gustatory stimulation by the cyanide. Oxygen consumption of the trout remained above pre-exposure levels for the majority of the test period. Oxygen consumption in the bullhead paralleled the changes in heart and ventilatory rates. Whole-body lactate levels of fingerlings of both species during cyanide exposure were measured to estimate the extent of anaerobiosis. Whole-body lactate levels were much greater in the bullheads than the trout, indicating a higher capacity for anaerobiosis, possibly due to a greater fuel supply. Overall, the trout responded to cyanide in a manner similar to that produced by environmental hypoxia whereas the bullheads experienced a gustatory stimulus which masked the hypoxia-like response. 相似文献
20.
An overview of stress physiology of fish transport: changes in water quality as a function of transport duration 下载免费PDF全文
下载免费PDF全文 This study brings an integrated analysis about the relationship between water deterioration and its physiological consequences in live fish transport. The analysis was focused on the transport water and its deterioration, and physiological challenges imposed on the fish. Usual commercial handling procedures employed to mitigate fish stress during transport were discussed. Future topics of research for the establishment of safer fish transport protocols were proposed. Transport was classified into short (≤8 h) or long transport (>8 h). The main issue in short transports should be the prevention of water pH reduction, while in long transports it is the increase in ammonia. Plasma cortisol is the most employed marker for stress and is acutely elevated upon short episodes of transport, but remains elevated even in long‐transport events. Plasma glucose is perhaps a better marker for handling stress. Plasma lactate, pH, osmolality CO2 and ions should be more often evaluated. Plasma Na+ and Cl‐ are very useful markers of acidosis, due to their respective exchange for H+ and , for acid–base regulation. The establishment of species‐specific transport protocols should be preceded by such combined analyses of water and physiological parameters. 相似文献