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1.
2012年9月对太子河流域39个采样点的底栖动物群落和水体环境因子特征进行野外调查,并运用香农威纳指数、均匀度指数和典范对应分析等方法分析底栖动物的群落结构。结果表明:在太子河流域共采集到底栖动物61种,以双翅目、蜉蝣目为主,各采样点底栖动物平均密度为0.64×10~3ind/m~2,平均生物量为20.03g/m~2,香农威纳指数和均匀度指数平均值分别为2.14和0.52。典范对应分析表明:影响太子河流域底栖动物群落的主要水体环境因子是总氮、流量和氨氮。综合分析得出:太子河流域受到了轻度污染。  相似文献   

2.
为掌握宁夏沙湖大型底栖动物群落状况,于2013年春季、夏季、秋季调查沙湖8个采样点的大型底栖动物群落结构,并评价沙湖水质状况。结果表明:3个季节在沙湖共采集了17种大型底栖动物,隶属6科,主要由水生昆虫、软体动物、节肢动物组成,且随季节与空间变化显著;沙湖大型底栖动物优势类群为水生昆虫幼虫;大型底栖动物生物指数较低,Shannon-Wiener生物多样性指数和Pielou均匀度指数平均值分别为0.91和0.51;依据多样性指数和大型底栖动物数量分布对沙湖水质进行综合评价,沙湖水域属重度污染,夏季沙湖污染最严重,秋季沙湖受污染状况略好于春季。  相似文献   

3.
霍堂斌  姜作发  张伟  刘刚 《水产学杂志》2012,25(3):31-35,46
2011年8月,对海浪河大型底栖动物群落结构进行了调查研究。本次调查共采集到了大型底栖动物14目31科56种,其中水生昆虫43种,分属7目21科,占总数75.44%。海浪河特有鱼类国家级水产种质资源保护区境内大型底栖动物共计13目30科51种,依群落数量看,蜉蝣目、毛翅目、双翅目为优势类群。海浪河大型底栖动物平均密度为180.19 ind.m-2、生物量为3.20 g.m-2。在各功能摄食生态类群中,捕食者最多,为25种,收集者15种,撕食者10种,刮食者6种。角锥毛石蚕(Brachycentinao)、泥苞虫(Setodes)、小划蝽(Siga substraia-ta)、Epeorus uenoi和Stenpsyche griseipennis是目前海浪河大型底栖动物的优势种。采用Shannon-Weiner生物指数、BI生物指数和Simposon生物指数对海浪河水质评价表明,各生物指数水质评价结果相似,洁净度排序趋势基本一致,均表明海浪河特有鱼类水产种质资源保护区境内水质比较清洁。  相似文献   

4.
于2014年秋季对济南地区水域的底栖动物的进行设点采样调查,并利用底栖动物香农维纳多样性指数和均匀度指数对水质进行评价。结果表明:济南地区水域共鉴定出底栖动物3门10目33种,以节肢动物门和软体动物门为主。底栖动物平均密度为865.42个/m2,底栖动物香农维纳指数和均匀度指数较低,平均值分别为1.28和0.67。综合各项指标评价认为济南流域秋季水质污染较为严重,为中度污染,应加大保护力度。  相似文献   

5.
为了解海南省临高县文澜江流域底栖动物群落结构特征,探索适宜的水质生物学评价方法,为文澜江流域环境监测、环境评价和科学管理提供数据参考。于2014年11月对文澜江流域17个点位底栖动物群落结构进行调查,并采用5种生物指数对水质现状进行了评价。结果表明,文澜江流域共采集底栖动物56种,隶属4门、7纲、29科,其中水生昆虫占绝对优势,共38种,占总数的67.86%;底栖动物密度和生物量分别为376.11个/m~2和200.79 g/m~2;多足摇蚊属(Polypedilum sp.)、米虾属(Caridina sp.)和环棱螺属(Bellamya sp.)为优势种,优势度分别为0.16、0.04和0.03。采用Goodnight-Whitley修正指数(GBI)和生物指数(BI)对文澜江流域水质整体评价结果均为清洁;采用Shannon-Wiener多样性指数、Margalef丰富度指数和生物学污染指数(BPI)的流域水质整体评估结果均为轻污染,3种水质生物指数评估结果基本相似,并与常规水质监测结果基本吻合。以水产养殖为主的水库出水口和流经临高县县城河道的水质处于中度污染程度,表明水产养殖废水、城市生活污水等对底栖动物的物种组成和群落结构造成了一定影响。  相似文献   

6.
2009年,对瓯江干流"玉溪电站~开潭大坝"段底栖动物的种类和数量进行了调查,并应用Hilsenhoff生物指数和理化指标对此干流段水质状况进行了评价。结果显示:本次调查共采集到底栖动物30种(属),隶属于19科。底栖动物平均密度为(1126±630)ind./m2,平均生物量为(42.183±10.645)g/m2,底栖动物的密度和生物量随站位变化明显。生物评价显示,3、5、7、8号采样点水体已污染或轻度污染;化学评价显示,大多数采样点水质基本处于Ⅲ类至Ⅴ类水水质水平。结果表明,"玉溪电站~开潭大坝"段水质已有一定程度的污染,且正处于富营养化状态。  相似文献   

7.
底栖动物对环境变化反应敏感,当水体受到污染时,底栖动物群落结构及多样性会发生改变。为了解白洋淀的底栖动物组成及水质状况,于2006年12月、2007年3~11月对白洋淀9个采样点的底栖动物进行了采样调查。共鉴定出底栖动物23种,其中,软体动物17种、环节动物2种、水生昆虫幼虫4种,与1958年的调查结果对比,发现物种种类数呈降低趋势。其中,中国圆田螺、中华圆田螺、绘环棱螺、羽摇蚊幼虫为全年分布种。应用Shannon-Wiener多样性指数对水质进行分析,可以看出白洋淀水质为中污染。  相似文献   

8.
黑龙江中游底栖动物群落结构与水质生物评价   总被引:1,自引:0,他引:1  
2010—2011年对黑龙江中游底栖动物群落结构进行调查研究,共采集到底栖动物16目49科117种,其中水生昆虫种类最多,为79种,分属7目34科,占总数67.52%。黑龙江中游底栖动物平均密度为58.37 ind/m2,生物量为34.62 g/m2。2010年平均密度以春季最高,秋季次之,夏季最低,平均生物量以秋季最高,夏季次之,春季最低。2011年秋季平均密度和平均生物量均高于夏季。黑龙江短沟蜷(Semisulcospira amurensis)、东北田螺(Viviparuschui)、圆顶珠蚌(Unio douglasiae)、截口土蜗(Galba truncatula)和生米蜉(Ephemera shengmi)是现阶段黑龙江中游底栖动物的优势种。聚类分析将7个调查断面分为3组,多维标度分析结果支持了聚类分析结果。多样性分析结果表明,Shannon-Weiner指数、Pielou均匀度指数、Simpson指数均以2010年春季最高,2010年秋季最低。功能摄食类群以刮食者占优,共计为41种。采用BI生物指数和FBI生物指数对黑龙江中游水质的评价结果基本一致,黑龙江中游水质处于清洁轻度污染等级。  相似文献   

9.
白洋淀底栖动物多样性调查及水质评价   总被引:4,自引:0,他引:4       下载免费PDF全文
底栖动物对环境变化反应敏感,当水体受到污染时,底栖动物群落结构及多样性将会发生改变。为了解白洋淀的底栖动物组成及水质状况,作者于2006年12月、2007年3月至11月对白洋淀9个采样点的底栖动物进行了采样调查。共鉴定出底栖动物23种,其中软体动物17种,环节动物2种,水生昆虫幼虫4种,与1958年的调查结果对比可以发现物种种类数呈降低趋势。其中中国圆田螺、中华圆田螺、绘环棱螺、摇蚊幼虫为全年分布种。应用香农-威纳多样性指数对水质进行分析,可以看出白洋淀为重、中污染。  相似文献   

10.
为系统了解红旗河大型底栖动物群落结构和水质现状,2017年和2018年夏季采用常规方法对红旗河流域进行2次调查。共采集大型底栖动物66种,隶属于10目30科,其中水生昆虫6目26科62种,占总数的93.94%。按照功能摄食类群划分,红旗河大型底栖动物包括收集者30种(最多,占总数的45.45%),撕食者19种,刮食者12种,捕食者5种。调查期间,红旗河大型底栖动物平均密度为73.1 ind/m~2,平均生物量为4.93g/m~2,2017年夏季红旗河大型底栖动物密度和生物量高于2018年,但差异不显著(P0.05)。相对重要性指数、K-优势曲线与Shannon-Weiner指数、Pielou均匀度指数和Simpson指数分析表明:红旗河底栖动物群落的相对重要性指数较高的种类均为水生昆虫,弯握蜉Drunella sp.1和瘤石蚕Goera sp.为2个调查年度共有的优势种;2018年K-优势曲线、Shannon-Weiner指数、Pielou均匀度指数和Simpson指数略高于2017年(P0.05);BI生物指数和Shannon-Weiner指数结果表明:红旗河水质基本处于清洁状态,水质条件较好。  相似文献   

11.
12.
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   

13.
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   

14.
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   

15.
16.
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   

17.
The endemic, anadromous cyprinidChalcalburnus tarichi is the only fish species known to occur in alkaline Lake Van (Eastern Anatolia, Turkey). EightC. tarichi were maintained individually in Lake Van water (17 – 19°C; pH 9.8; 153 mEq·I–1 total alkalinity; 22 total salinity) and tank water samples analyzed for 24 h in 2 to 4 h intervals. At zero time, < 1µM ammonia was present and urea was undetectable in the tank water; at 24 h, total ammonia and urea made up 114±32 and 35±25µM, respectively. Over the experimental period, ammonia-N and urea-N excretion averaged 1041±494 and 607±169moles·kg–1 fish·h–1, respectively. The extent of urea excretion was highly variable between specimens. Uric acid excretion was not detectable.Urea was present at high concentrations in all tissues and plasma (25 – 35moles·g–1·ml–1) of freshly caughtC. tarichi; total ammonia content of the tissues was by a factor of 1.9 (liver) to 3.0 (brain) lower. High arginase activity (2.4±0.2 U·min–1·g–1) was detected in the liver ofC. tarichi but ornithine carbamoylphosphate transferase, a key enzyme of the ornithine-urea-cycle, was absent. Ureagenesis is likely through degradation of arginine and/or uricolysis. High glutamine synthetase activity (11±0.6 U·min–1·g–1) and low ammonia content in brain suggest that, like other teleosts,C. tarichi has an efficient ammonia detoxification in the brain, but in no other tissue.Nitrogenous waste excretion at alkaline pH is discussed. The ability ofC. tarichi to excrete high levels of ammonia at extremely alkaline pH is unique among teleosts studied so far. The mechanism of ammonia excretion under Lake Van conditions remains to be elucidated.  相似文献   

18.
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   

19.
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   

20.
  1. Humanity is facing a biodiversity crisis, with freshwater-associated biodiversity in a particularly dire state. Novel ecosystems created through human use of mineral resources, such as gravel pit lakes, can provide substitute habitats for the conservation of freshwater and riparian biodiversity. Many of these artificial ecosystems are subject to a high intensity of recreational use, however, which may limit their biodiversity potential.
  2. The species richness of several taxa (plants, amphibians, dragonflies, damselflies, waterfowl, and songbirds) was assessed and a range of taxonomic biodiversity metrics were compared between gravel pit lakes managed for recreational fisheries (n = 16) and unmanaged reference lakes (n = 10), controlling for non-fishing-related environmental variation.
  3. The average species richness of all the taxa examined was similar among lakes in both lake types and no substantial differences in species composition were found when examining the pooled species inventory. Similarly, there were no differences between lake types in the presence of rare species and in the Simpson diversity index across all of the taxa assessed.
  4. Variation in species richness among lakes was correlated with woody habitat, lake morphology (surface area and steepness), and land use, but was not correlated with the presence of recreational fisheries. Thus, non-fishing-related environmental variables had stronger effects on local species presence than recreational fisheries management or the presence of recreational anglers.
  5. Collectively, no evidence was found that anglers and recreational fisheries management constrain the development of aquatic and riparian biodiversity in gravel pit lakes in the study region; however, the conservation of species diversity in gravel pit lakes could benefit from an increasing reliance on habitat enhancement activities.
  相似文献   

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