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1.
采用在体暴露试验的方法,研究了不同浓度五氯酚钠(Na-PCP)在不同暴露时间(24、48、72和96 h)下对梨形环棱螺的急性毒性,以及Na-PCP对肝脏、鳃和腹足中精氨酸激酶(AK)活性的影响.结果显示,Na-PCP对梨形环棱螺的半致死浓度为0.411 mg/L,安全浓度为0.0411 mg/L;在Na-PCP暴露下,梨形环棱螺肝脏中单位蛋白AK活性在低浓度下被诱导增长,在高浓度下则出现被抑制的现象,鳃和腹足中单位蛋白AK活性伴随Na-PCP浓度的增加而下降,表现出时间剂量效应,且腹足中下降幅度相对鳃中较大.试验结果表明AK活性可以作为指示五氯酚钠对梨形环棱螺毒理效应的生物标志物.  相似文献   

2.
为了研究Cu2+对厚壳贻贝(Mytilus coruscus)的毒性效应,开展了厚壳贻贝幼体在Cu2+水溶液中的96 h急性毒性效应实验及7 d胁迫实验,将厚壳贻贝内脏团、鳃组织中的超氧化物歧化酶(Superoxide dismutase, SOD)、过氧化氢酶(Catalase, CAT)、脂质过氧化水平(Lipid peroxidation, LPO)以及金属硫蛋白(Metallothioneins, MT)作为生物标志物,应用综合生物标志物响应(Integrated biomarker response, IBR)指数整合4种生物标志物。结果显示,Cu2+对厚壳贻贝幼体的96 h半致死浓度为1.55 mg/L,内脏团、鳃组织各个生物标志物指标呈现出不同的变化趋势,内脏团、鳃组织SOD、CAT活性以及鳃组织MT含量均呈先上升后下降的趋势,内脏团组织MT含量及内脏团、鳃组织MDA含量均呈持续上升的趋势。IBR值呈先上升后下降的趋势,内脏团组织IBR值高于鳃组织。研究表明,生物标志物的变化与Cu2+暴露浓度有关,IBR分析可以辨别不同暴露浓度之间的差异,可以作为量化污染物暴露效应的有效工具。  相似文献   

3.
通过重金属暴露法,研究了不同质量浓度Cd2+（0.005、0.025、0.05、0.1 mg/L）在168 h内对缢蛏消化腺和鳃组织谷胱甘肽硫转移酶（GST）、酸性磷酸酶（ACP）、碱性磷酸酶（AKP）活性的影响。结果显示,Cd2+对两种组织GST活性均有激活作用,且高浓度比低浓度更易快速诱导其活性,但在暴露的后期（>96 h）,两个较高浓度组（0.05、0.1 mg/L）GST活性均出现下降;两种组织的ACP活性（鳃组织0.005 mg/L组除外）在暴露的6h即被显著诱导,并表现出剂效关系,但高浓度组更快达到峰值后就持续下降,于暴露中后期（>72 h）被不同程度抑制;消化腺（0.005 mg/L浓度组除外）和鳃AKP活性在暴露168 h内均表现出“抑制-诱导-抑制”的规律,并且较高浓度组活性反而比低浓度组更易被激活,各组AKP活性被诱导达到最高值后就持续下降直至被再次抑制。Cd2+在低浓度水平下即能引起缢蛏两种组织的GST、ACP、AKP活性变化,表明Cd2+的胁迫可对缢蛏机体的解毒体系和新陈代谢产生影响。  相似文献   

4.
为研究盐度对大鳞副泥鳅（Paramisgurnusdabryanus）Na+-K+-ATP酶（NKA）、抗氧化酶活性及组织结构的影响,试验设置4、8、12共3个盐度组和一个淡水组（对照）,以全长（17.60±0.69）cm,体质量（35.51±5.30）g的大鳞副泥鳅进行14 d胁迫试验。结果表明：盐度升高使鳃Na+-K+-ATP酶活力上升,第7 d 时3个试验组Na+-K+-ATP酶活性均达到峰值且盐度8和12组显著高于淡水组（P<0.05）。肝脏SOD和CAT活性均表现为先上升后下降的趋势,且分别于胁迫12 h和2 d时达到最大值;3个盐度组的GSH-PX酶活性在6 h和12 h均有所升高,且盐度12组显著高于淡水组（P<0.05）。盐度4、8和12组肝脏MDA含量分别在第1 d和7 d达到最大值且显著高于淡水组（P<0.05）。组织切片结果显示,盐度12组的鳃小片变窄,鳃小片间距变大,泌氯细胞数量增多;肝细胞空泡化严重,血窦扩张范围增大,并出现细胞轮廓模糊、细胞核偏移、细胞核溶解。上述结果表明,盐度胁迫对大鳞副泥鳅的Na+-K+-ATP酶、抗氧化酶活性具有显著的诱导作用,并对其鳃和肝组织造成损伤。  相似文献   

5.
铜在西施舌鳃和消化腺蓄积及对SOD和CAT活性影响   总被引：1，自引：0，他引：1  
为了研究重金属铜(Cu2+)在西施舌鳃、消化腺组织中的蓄积规律及其对超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性的影响,本文采用急性毒性实验的方法,将西施舌置于不同浓度Cu2+溶液进行实验。结果显示,鳃组织中的Cu2+在第4天时达最大蓄积量,为79.7μg/g,消化腺组织则在第8天蓄积量达最大,为139.2μg/g,Cu2+的最大蓄积均出现在0.16 mg/L胁迫组,消化腺Cu2+浓度蓄积均随胁迫浓度的增加而升高;鳃、消化腺组织CAT活性均呈先升高后降低趋势,且后者CAT活性显著高于前者;鳃组织SOD活性呈先升高后降低趋势,且受到显著诱导(P0.05),消化腺组织的SOD活性则呈下降趋势,在0.16 mg/L胁迫组,鳃和消化腺组织的SOD活性均分别在第3~4天受到极显著抑制(P0.01),表明CAT和SOD活性可作为指示西施舌受Cu2+污染程度的重要指标。  相似文献   

6.
研究了镉（Cd）、铜（Cu）2种重金属单一暴露下菲律宾蛤仔（Ruditapes philippinarum）肝胰腺和鳃组织内的重金属富集特征和抗氧化酶活力变化特点。结果表明,蛤仔肝胰腺与鳃对Cd、Cu的富集量随重金属浓度与暴靠时间的增加而增火,具有明显的浓度效应与时间效应;菲律宾蛤仔对Cd的富集能力高于Cu,H．肝胰腺中审盖属的蓄积量高于鳃;蛤仔肝胰腺和鳃组织中超氧化物歧化酶（SOD）、谷胱廿肽过氧化物酶（（;Px）和谷胱竹肽硫转移酶（CST）活力在暴露的某些时段被显著诱导（P〈0．05）,似随暴露时问延长或重金属浓度增加,SODf11GST活力则被显著抑制（P〈O．05）,而CPx活力随暴露时问延K逐渐恢复至对照组水平、菲律宾蛤仔肝胰腺和鳃2种组织中SOD和GST的活性变化可作为海洋Cu^2＋Cd^2＋钙染的牛物标志物．  相似文献   

7.
Cu2+胁迫对魁蚶生理生化和组织结构的影响   总被引：1，自引：0，他引：1  
采用生物毒性测试的方法,研究了持续暴露96 h不同浓度Cu2+胁迫对魁蚶生理代谢、组织结构及酶活性的影响。实验设置0.01、0.05、0.10、0.50和1.00 mg/L组5个浓度梯度,不加Cu2+的正常海水作为对照。结果显示,Cu2+胁迫对魁蚶耗氧率(OR)、排氨率(NR)、氧氮比(O∶N)均有显著影响,并且与暴露时间和浓度有关。初次暴露时,OR,NR和O∶N都迅速下降,最低值都出现在1.00 mg/L浓度组,分别为(0.005±0.001)mg/(g·h)、(0.5±0.05)μmol/(g·h)、0.7±0.1,仅为对照组的1%、29%和3%。暴露72 h内Cu2+胁迫均使魁蚶代谢率不同程度下降,之后不同处理组出现差异分化。暴露96 h时,魁蚶对低浓度Cu2+暴露表现出适应,0.01 mg/L处理组呼吸代谢恢复至正常水平,O∶N与对照组无差异,组织结构也未见明显损伤;浓度超过0.05 mg/L处理组魁蚶生理代谢及组织结构受显著影响,O∶N大多降至9以下,出现鳃丝受损和组织结构散乱等明显损伤;0.10 mg/L处理组魁蚶体内ACP和ALP活性在鳃组织中增强,肝脏中受到抑制,而GPX和GST活性增强。研究表明持续暴露96 h Cu2+浓度≥0.05 mg/L环境显著影响魁蚶生理代谢及组织结构,0.10 mg/L Cu2+浓度显著影响魁蚶组织中ACP、ALP、GPX和GST的活性。研究结果为认知魁蚶等滩涂贝类对Cu2+胁迫的响应机制提供基础数据,为预防滩涂潜在重金属污染风险及生物修复提供参考。  相似文献   

8.
重金属在鲫幼鱼组织中的积累与分布   总被引：10，自引：0，他引：10  
研究了安全浓度的混合重金属铜(Cu)、锌(Zn)、铬(Cr)和镉(Cd)污染物在鲫幼鱼组织中短期的积累和分布。实验结果表明:Cu、Zn、Cd和Cr4种重金属之间的联合作用为毒性剧增的协同作用。Cd和Cr在鲫鱼的鳃和肝脏中有极明显的积累(P<0.01),在肌肉中的积累并不明显。除在暴露的12h和24h时观察到Zn在肝脏中有较明显的积累(P<0.05)外,Cu和Zn暴露期间在鱼体各组织中无明显的积累。观察到Cd、Cr和Zn3种重金属的暴露初期,在肝脏中都可见到一个积累高峰,而后又有所下降,推断这与混合重金属间的相互作用有关,也可能与肝脏中金属硫蛋白(MT)的解毒功能有关。Cd和Cr在鳃和肝脏中分别属中度和轻度富集重金属,而Zn在肝脏中属中度富集重金属。  相似文献   

9.
采用半静止染毒法,探讨甲氰菊酯对鲤（Cyprinus carpio）的急性毒性和对鳃组织Na＋-K＋-ATP酶活性的影响及组织的病理损伤。急性毒性结果表明,甲氰菊酯对鲤的96 h半致死质量浓度（LC50）为8.53μg·L-1,安全质量浓度（SC）为0.853μg·L-1。设置1/2 96 h LC50以下的5个质量浓度0、0.43μg·L-1、0.85μg·L-1、1.71μg·L-1、4.27μg·L-1作用于鲤21 d,分别在第1、第3、第7、第14和第21天采集组织样品进行酶活测定以及组织病理学观察。结果表明,鳃组织中Na＋-K＋-ATP酶活性随着暴露时间的推移其动态变化呈先下降后上升、之后又有所回落的趋势。暴露第3天各组酶活性降至最低点,与对照组相比差异极显著（P〈0.01）,其抑制率分别达到42.49%、27.48%、59.03%和46.31%;第14天各组酶活达最高值并显著（P〈0.05）或极显著（P〈0.01）高于对照组;第21天除最高浓度组显著低于对照组外,其余3组仍高于对照组。H-E染色显示,鳃组织学损伤主要是鳃小片扭曲,上皮细胞和柱状细胞脱落,鳃小片毛细血管扩张充血,粘液细胞和基部细胞增生,严重时鳃小片粘连,呈棍棒状病变。以上损伤具有剂量相关性和时间积累效应。  相似文献   

10.
太湖似刺鳊鮈染色体组型分析及细胞核DNA含量   总被引：3，自引：0，他引：3  
采用PHA、秋水仙素碱腹腔或背部肌肉注射,活体培养法,用空气干燥法制片,运用Micromeasure version 3.3染色体分析软件和Photoshop 7.0对似刺鳊鮈染色体数目和核型进行了分析;同时,取似刺鳊鮈血细胞、尾鳍、鳃、肌肉、性腺和肝脏为材料,以鸡血细胞为DNA标准（2.50pg/2c）,使用EPICS-XL型流式细胞仪测定了似刺鳊鮈细胞核DNA含量。结果显示：染色体众数2n=50,染色体大小的绝对值为0.86～2.32µm,平均长度为1.63µm,未观察到次缢痕及异配型染色体,亦未发现有随体,核型公式为18m+20sm+8st+4t,NF=88。6个组织细胞核DNA含量分别为：尾鳍3.779 pg/2c,鳃4.007 pg/2c,肌肉3.819 pg/2c,性腺(卵巢4.242 pg/2c、精巢1.842 pg/2c),肝脏3.905 pg/2c。尾鳍、鳃、肌肉和肝脏的细胞核DNA含量不存在显著差异（p＞0.05）,但都极显著高于血细胞DNA含量（p＜0.01）;卵巢细胞核DNA含量约为精巢的2倍。  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   

13.
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14.
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   

15.
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   

16.
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.
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.
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   

19.
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   

20.
There has been growing concern about the overuse of antibiotics in the ornamental fish industry and its possible effect on the increasing drug resistance in both commensal and pathogenic organisms in these fish. The aim of this study was to carry out an assessment of the diversity of bacteria, including pathogens, in ornamental fish species imported into North America and to assess their antibiotic resistance. Kidney samples were collected from 32 freshwater ornamental fish of various species, which arrived to an importing facility in Portland, Oregon from Colombia, Singapore and Florida. Sixty‐four unique bacterial colonies were isolated and identified by PCR using bacterial 16S primers and DNA sequencing. Multiple isolates were identified as bacteria with potential to cause disease in both fish and humans. The antibiotic resistance profile of each isolate was performed for nine different antibiotics. Among them, cefotaxime (16% resistance among isolates) was the antibiotic associated with more activity, while the least active was tetracycline (77% resistant). Knowing information about the diversity of bacteria in imported ornamental fish, as well as the resistance profiles for the bacteria will be useful in more effectively treating clinical infected fish, and also potential zoonoses in the future.  相似文献   

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