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1.
几种常见污染物对虾的危害   总被引:1,自引:0,他引:1  
本文针对目前养虾中比较严重的几种污染,讨论了重金属离子,有机农药,化肥及虾的残饵排泄物对虾的毒害作用及致毒机理。以求为治理污染和虾病的防治提供一些理论依据。一、几种重金属离子的毒害工业中重金属的种类较多、用途较广,由于重金属不易降解,一旦这些重金属进入虾塘,就会对虾造成危害。1、铅铅是金属元素中对环境污染最为严重的金属元素之一,它是一种蓄积类毒物,少量缓慢的接触也会导致蓄积性中毒。铅被吸入机体后,在有CO2存在的情况下,由于是弱酸性可促进铅的溶解和吸收,铅可被呼吸道的吞噬细胞吞噬而带进血液。在虾体内,铅离子与…  相似文献   

2.
铅在鲤鱼体内积累和排出的试验研究   总被引:1,自引:0,他引:1  
本文讨论水中溶解铅在鲤鱼体积累和排出的过程。水中铅浓度为0.1ppm、1.0ppm和5.0ppm。积累程度随试验铅浓度和暴露铅时间增加而加强,浓缩系数则基本相反。当铅积累到一定程度时,则出现吸收—积累—排出的动态平衡,鱼体铅在清水中排出的速度随铅积累量的增加而缓慢。各组织铅积累量随着不同暴露时间会有不同的消长,最终各组织内铅积累依次为肝>肠>鳃>肌肉>骨骼;进入鱼体之铅能抑制胆碱酯酶活力和降低血红蛋白含量,说明神经系统和造血系统已遭损害。  相似文献   

3.
近年来,随着社会经济的发展,大量未经处理或处理不完全的污染物排入江河,并最终进入海洋,从而使水生生物赖以生存的环境受到各种外来物质的影响,水产养殖环境恶化,铅等铅类有害物质在水生生物体中经富集作用而蓄积。随着水产品在人们的日常食谱中所占比重越来越高,人们也日益关心水产品中铅尤其是铅的污染问题。一、铅的简介铅是重金属污染中毒性较大的一种,一旦进入人体将很难排除。它对神经系统、骨骼造血功能、  相似文献   

4.
水中增氧主要有三种方法。一是生物增氧方法,二是物理增氧方法,三是化学增氧方法。用增氧机向水中增氧就是一种物理增氧方法。目前我国广大科技人员开发了众多形式和型号的增氧机。这些增氧机主要有三种增氧功能。一是增加水和空气的接触面积,利用机械能将水喷到空气中,或形成飞溅的小水珠,增加水和空气接触面积,使空气中氧有更多机会渗入水中。二是利用正负压力,将空气压入或吸入水中。三是促进上、下水层水的流动,将上层溶氧高的水和下层溶氧低的水混和交换,使上、下层水溶氧相近。这不但能避免表面过饱和氧向空气中逸  相似文献   

5.
橄榄蛏蚌软组织4种微量元素含量分析   总被引:1,自引:0,他引:1  
许巧情  吴岩  袁汉文 《水利渔业》2006,26(6):29-29,100
利用原子吸收分光光度法测定了橄榄蛏蚌不同组织的锌、铜、铅、镉等4种金属元素的含量。锌平均含量最高,其次是铅。足、肝脏中4种微量元素含量高于其它组织,特别是铅和镉;铜在外套膜中含量很高,而在闭壳肌中最低。  相似文献   

6.
贝类对重金属具有较强的蓄积能力,铅是贝类体内常见的重金属污染元素,贝类的质量安全问题已受到广泛关注。文章主要概述了贝类中铅的来源和危害、限量标准,重点介绍了贝类体内铅的主要前处理和检测方法,以及风险评估方法,并对海水贝类中铅暴露的风险评估研究进行归纳梳理,以期为贝类消费者的食用安全提供参考,有助于促进中国贝类经济发展。  相似文献   

7.
李娜  许鹏  王兰 《水产学报》2017,41(10):1571-1577
为探究河南华溪蟹副性腺的功能以及铅对副性腺功能的影响和毒性机理,首先采用钙离子载体A23187诱导法对河南华溪蟹进行精子顶体反应诱导实验,结果显示副性腺匀浆+A23187组合下的顶体反应诱导率最高,可达78%,这提示河南华溪蟹副性腺具有调节精子顶体反应的作用。在此基础上采用急性铅染毒的方法,设1个对照组和5个铅处理组(3.675、7.35、14.70、29.40和58.80 mg/L),染毒时间分别为3、5和7 d,检测了铅染毒后的副性腺对精子顶体反应诱导率的影响,以及染毒后副性腺中活性氧(ROS)含量、蛋白质羰基化(PCO)含量、DNA-蛋白质交联率(DPC)的变化。结果显示,随着铅染毒剂量的增加和染毒时间的延长,精子顶体反应诱导率明显下降,副性腺中ROS含量和PCO含量升高,但DPC无明显变化。研究表明,铅对河南华溪蟹副性腺有明显的生殖毒性,可降低其在精子顶体反应诱导过程中的作用,主要原因是铅诱导产生的ROS使副性腺中蛋白质发生了氧化损伤。  相似文献   

8.
[目的]研究利用蛤蜊壳制备的羟基磷灰石用于吸附去除蚝油中重金属铅的可行性。[方法]利用含有铅离子的水溶液优化羟基磷灰石的吸附条件,进而探讨羟基磷灰石对蚝油中重金属铅的脱除效果,并分析脱除工艺对蚝油品质的影响。[结果]在羟基磷灰石用量为0.17 mg/m L,蚝油样品中铅离子含量为2.33 mg/m L以下时,羟基磷灰石对蚝油中重金属铅离子的吸附率达到98%以上,而且铅离子的浓度越高,吸附率越大。通过对吸附前后蚝油主要理化性质的对比发现,吸附作用对蚝油的主要品质指标没有显著影响,而且微量元素Ca、Zn的含量有所增加。[结论]用蛤蜊壳制备的羟基磷灰石能够有效吸附蚝油中的重金属铅,这不但为蚝油中重金属铅的控制提供了新的处理技术,而且还为蛤蜊壳的资源化及深度利用提供了新的思路。  相似文献   

9.
增氧机使用技术问答   总被引:1,自引:0,他引:1  
1.增氧机在池塘养殖中有什么作用? 增氧机的作用(以叶轮式增氧机为例)一是增加空气中的氧气向池塘水体溶解,增氧机开动后,叶轮搅动形成水花,增加了水和空气的接触面积和接触机会,使空气中的氧气溶入水中。叶轮旋转时,其下方的通气管在旋转方向背面产生负压区,空气就从管  相似文献   

10.
采用半静态暴露染毒方式探讨了建鲤(Cyprinus carpio var.Jian)幼鱼肝胰脏、肠、鳃和肌肉中重金属铅的积累和净化特征,暴露水体含铅量为0.506μg/L。结果表明,不同部位中铅的积累量差异显著(P<0.05),积累量为肝胰脏>鳃>肠>肌肉。建鲤移入清水后,随着净化时间的延长,不同组织中铅的含量均逐渐降低,但变化趋势不同。肠中的铅被迅速净化;肝胰脏中铅的净化速度初期较快,之后变化缓慢,呈现波浪式起伏;鳃中的铅净化缓慢,肌肉中的铅含量下降缓慢,但在净化期其铅含量均低于国家标准。  相似文献   

11.
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   

12.
13.
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   

14.
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   

15.
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   

16.
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   

17.
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 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   

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