首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Histopathological alterations in Nile tilapia, Oreochromis niloticus, aged 3 months and subjected to acute and subchronic alachlor exposure were studied by light microscopy LC50 values of alachlor for 24 hr 48 hr, 72 hr and 96 hr were 963.6, 563, 448, and 381.9 microg l(-1), respectively and the maximum acceptable toxicant concentration (MATC) was 350 microg l(-1). Fish were exposed to 381.9 (acute) and 35 microg l(-1) (sub-chronic) of alachlor for 24, 48, 72 and 96 hr and 90 days, respectively Gill lamellae and kidney tubules were the primary target organs for the acute toxic effect of alachlor while in the subchronic exposure, the toxic effect on the gills was less marked than that of the kidneys and liver Gill alterations included edema of the epithelial cell system, aneurisms with some ruptures, hypertrophy and hyperplasia of epithelial cells. The liver showed hydropic swelling of hepatocytes and vacuolation. Lipid vacuoles were observed in hepatocytes in the second and third month of subchronic exposure. The kidney showed hydropic swelling of tubular cells, lipid vacuole accumulation in many tubules, and nuclear pyknosis. The findings of this study could be used as a guideline forbiomonitoring programs on populations of Nile tilapia cultured near alachlor contaminated areas.  相似文献   

2.
The effect of phenol on haematological components of Indian major carps, Catla catla, Labeo rohita and Cirrhinus mrigala were observed. After exposure to sublethal concentrations of 5.17 mg l(-1), 6.06 mg l(-1) and 6.99 mg l(-1), the number of red blood cells, haemoglobin content and packed cell volume all decreased but the glucose level increased. The order of decrease in the haematological components of the three fish is in the order of Catla catla > Labeo rohita > Cirrhinus mrigala.  相似文献   

3.
B. Patel  J. T. Eapen 《Marine Biology》1989,103(2):193-202
Changes in vital physiological activities — shell movements and burrowing behaviour, uptake and depuration, filtration and respiration — on exposure to sublethal concentrations of naphthalene (Nap) were investigated in the tropical arcid blood clam Anadara granosa L. from the Bombay coast in 1986. On exposure to ambient concentrations exceeding 5g Nap ml-1, shell valves opened widely within the first hour of exposure. The compressed muscular foot was stretched vertically upwards with copious secretion of mucus, and did not exhibit any evidence of burrowing behaviour. Those exposed to 5g Nap ml-1 regained their normal physiological activities on transfer to stressor-free medium, whereas those exposed to higher levels became intoxicated and narcotized. Bioaccumulation of Nap was dependent upon environmental concentration, increasing exponentially with time over a 9h exposure period. Further exposure, up to 96h, however, did not increase tissue levels substantially. About 65% of the total body burden of Nap was depurated within 3h of transfer to Nap-free medium. Rates of filtration and oxygen consumption were significantly reduced (ca 70%, p<0.001) compared to control clams. Percent inhibition in these physiological activities was dependent upon tissue and ambient concentrations of Nap. On transfer to pollutant-free medium, clams exhibited remarkable recovery. Rates of both filtration and oxygen consumption were gradually increased and restored to normal levels, as observed in controls. However, clams exposed to upper limits lost their ability to burrow back into the sedimentary bed, leaving them susceptable to predators. Furthermore, induction of anaerobiosis and disruption of osmotic balance on exposure to Nap together with aerial exposure at low-water periods and salinity changes, acted synergistically and proved detrimental. The rates of growth and mortality observed in the natural population of blood clams, harvested from the coastal waters off Bombay, have been explained in terms of the impact of petroleum and allied waste products released from petrochemical industries.  相似文献   

4.
Callus induced from leaf explants of Pueraria lobata seedlings were suspended in Gamborg B5 medium supplemented with 1 mg l(-1) 2,4-dichlorophenoxyacetic acid, 1 mg l(-1) naphthalene acetic acid, 0.5 mg l(-1) kinetin and 30 g l(-1) sucrose. The effects of coconut milk and casein hydrolysate (CH) on cell growth and yields of puerarin and isoflavones in cells suspension were studied. The contents of total isoflavones and puerarin in suspension cultures were determined by spectrophotometry and HPLC. Coconut milk (10%, filter sterilized) decreased the growth of cell cultures and the accumulation of total isoflavones, while 0.2% CH promoted the growth of cell cultures and the accumulation and release of puerarin and total isoflavones. The total yield of puerarin and isoflavones were 34% and 40.8% higher than in the control, respectively. The optimum medium for cell cultures of leaves of P. lobata seedlings was B5 liquid medium supplemented with 2% sucrose, 1.0 mg l(-1) 2,4-D, 1.0 mg l(-1) NAA, 0.5 mg l(-1) kinetin and 20 mg l(-1) CH. The procedure use is a potentially useful for the production of isoflavones.  相似文献   

5.
The influence of silt on growth of juvenile hard clams Mercenaria mercenaria (L.) (9 mm in mean shell length) was investigated in the laboratory using mixed suspensions of algae (50x106 Pseudoisochrysis paradoxa cells l-1) and fine-grained bottom sediments (0 to 44 mg l-1). Growth rates, expressed as percent increase in ash-free dry tissue weight, were not significantly affected by sediment concentrations up to 25 mg l-1. Significant reduction in growth (by 16% relative to controls fed only algae), and condition of clams, occurred at 44 mg silt l-1. The results of the 3-week growth experiment agree well with predictions made in an earlier study by integrating results of shortterm physiological measurements. Growth rates obtained with experimental algal-silt diets at 21°C (2.6 to 3.3% increase in dry tissue weight d-1) were comparable to those determined at ambient concentrations of Great South Bay particulates at 20°C (0.9 to 4.0% d-1). Levels of particulate inorganic matter in seawater from Great South Bay, New York, exhibited pronounced daily changes, and ranged from 6 to 126 mg dry weight l-1. Growth enhancement by the addition of silt to an algal diet, reported in mussels, surf clams and oysters, was not found in M. mercenaria. It is suggested that these three species are better suited than hard clams for culturing efforts in inshore turbid waters above uncompacted, muddy bottoms.Contribution No. 452 from the Marine Sciences Research Center, State University of New York at Stony Brook, USA  相似文献   

6.
The effect of sublethal concentration (29 mg/l) of cadmium on haematological parameters of Channa punctatus after the exposure periods of 7, 15 and 30 days were studied. In treated groups of cadmium exposed fish have been found to significantly decreased in total erythrocyte count, haemoglobin content, packed cell volume, mean corpuscular haemoglobin concentration and oxygen carrying capacity of blood, and at the same time the white blood cell count, mean cell volume and mean corpuscular haemoglobin were found to significantly increased. Both increasing and decreasing of the above mentioned haematological characteristics of blood cells of cadmium intoxicant are mainly with time dependent effects. With regard to the pathological characteristics of blood cells of cadmium intoxicant fish shows fragility and rupture of erythrocytic membrane and leads to haemolysis, which are very severe on 30 day of exposure group.  相似文献   

7.
Cellular and subcellular responses of the marine burrowing bivalve Venus verrucosa collected from the north-eastern coastline of Malta from January to June 1985, after exposure to petroleum hydrocarbons (PHC) were investigated. After long-term exposure to 100 gl-1 of water-accomodated fractions (WAF) of crude oil, PHC were found to accumulate most rapidly in the digestive gland and then in the gills, with saturation levels being reached within 100 d of exposure in both cases. PHC accumulation, both in the mantle and muscle tissues, was more gradual and consistent throughout the whole exposure period. After 150 d of exposure, the digestive cells of the digestive gland were significantly reduced in height (atrophy) and exhibited reduced lysosomal membrane stability. After 144 h of exposure to higher concentration of PHC (820 and 420 gl-1), several cytological effects were recorded, including an increase in cell volume and activity of gill mucocytes as well as in the number of haemocytes in gill blood sinuses. There was also evidence of damage to the epithelial lining of the foot, stomach and style sac and marked atrophy of the digestive cells of the digestive gland. The significance of such responses is discussed.  相似文献   

8.
When exposed to Prudhoe Bay crude oil in flowing seawater for 180 days, the small intertidal clam Macoma balthica showed behavioral, physical, physiological and biochemical changes. At a high concentration of oil in seawater (3.0 mg l-1) burrowing rate decreased, respiration rate increased, growth was inhibited, and very high mortalities resulted. The lowest concentration of oil in seawater (0.03 mg l-1) inhibited growth and caused reabsorption of gametes. One group of adverse oil effects which was related to sluggishness and disorientation of the clams appeared after a week of exposure to oil; another group related to a negative energy balance was not observed until 60 days. We conclude that chronic exposure of M. balthica to oil-in-seawater concentrations even as low as 0.03 mg l-1 will, in time, lead to population decreases.Please address requests for reprints to Dr. D. G. Shaw at the Institute of Marine Science  相似文献   

9.
Short-term laboratory feeding experiments were conducted to determine the response of the hard clam Mercenaria mercenaria (L.) (32 mm in mean shell length) to increasing sediment concentrations. Clams were fed mixed suspensions of Pseudoisochrysis paradoxa (50 and 150 cells l-1) and bottom sediments (0 to 44 mg l-1). Algal ingestion rate deelined with increasing sediment loads. This resulted primarily from a reduction in clearance rate, which declined by 0.08 l h-1 g-1 (1.3%) for every 1 mg l-1 increase in sediment load. This reduction was of similar magnitude for juvenile (13 mm) clams. At the algal concentrations tested, pseudofaeces production was intermittent and inconspicuous below about 10 mg silt l-1. Loss of algae in pseudofaeces increased with increasing sediment loads; however, even at the highest silt and algal concentrations, clams lost a maximum of only 18% of the algae cleared from suspension. Thus, pseudofaeces production is not expected to cause significant loss of algal food at the sediment concentrations normally encountered in the natural environment ( ca 40 mg silt l-1). Absorption rate of total organic matter remained constant, at least up to silt concentrations of 20 mg l-1. Experiments using dual 51Cr:14C-formaldehyde-labelled sediment indicated that clams were able to counteract the dilution of algae by absorbing a considerable fraction (21 to 22%) of detrital sedimentary organics. Absorption efficiency of pure P. paradoxa ranged from 82% at 50 cells l-1 to 58% at 150 cells l-1. Integration of physiological rate measurements suggests that at moderate to high algal concentrations (300 g Cl-1), growth improvement by the addition of silt, documented in mussels, surf clams and oysters, is unlikely to occur in M. mercenaria. It is suggested that a suspension-feeding bivalve's success in maximizing its energy gain in a turbid environment depends on the combination of two features: a high selection efficiency and a high rate of pseudofaeces production. It is proposed that species which regulate ingestion primarily by producing pseudofaeces are better adapted to cope with high suspended sediment loads than species such as M. mercenaria, which control ingestion mainly by reducing clearance rate.Contribution No. 451 from the Marine Sciences Research Center, State University of New York at Stony Brook, USA  相似文献   

10.
采用离体细胞测试技术,研究三氯乙烯(TCE)、四氯乙烯(PCE)对中国仓鼠卵巢细胞(CHO)的细胞毒性作用。3-(4,5-二甲基噻唑-2)-2,5-二苯基四氮唑溴盐(MTT)试验结果显示三氯乙烯、四氯乙烯对CHO细胞的半数生长抑制浓度(IC_(50))分别为590 mg·L~(-1)、281 mg·L~(-1)。三氯乙烯、四氯乙烯暴露可导致CHO细胞膜损伤,并且诱导细胞活性氧的产生。经不同浓度的三氯乙烯、四氯乙烯作用24 h后,细胞内超氧化物歧化酶(SOD)活性受到抑制;染毒浓度较低时细胞过氧化氢酶(CAT)活性呈激活势,染毒浓度过高CAT酶活性受到抑制。研究表明在体外培养条件下,氯乙烯类污染物诱导氧化应激可能是其产生细胞毒性的作用机制之一。  相似文献   

11.
Experiments were conducted to evaluate the toxic effects ofmonocrotophos in ciliate models Paramecium caudatum and Oxytricha fallax. In acute toxicity studies higherconcentrations of monocrotophos caused marked increase in mobility of cells exhibiting rocking movements within two mins of exposure but were decreased after 30 mins. LC50 value by mortality curve for 3 hr acute toxicity test of Oxytricha fallax and Paramecium caudatum was found 307.744 +/- 33.27 mg l(-1) and 332.284 +/- 57.52 mg l(-1) respectively. Oxytricha fallax was found sensitive than Paramecium caudatum to monocrotophos. In acute exposure cells showed deformities such as swelling, oval shaped deformity and in higher concentrations shortening of longitudinal axis with blackening of cytoplasm occurred. The length of paramecia was reduced prominently. Similarly enlargement of contractile vacuole and stress egestion of food vacuoles was also observed. The morphological studies showed the changes in shape, size, colour and width of Paramecia and Oxytricha. Frequencies of macronuclear aberrations were significant showing deformities such as rod shaped, elongation, fragmentation, diffusion and total absence of nucleus and were concentration dependent. The data provided in the present study on interaction of pesticides with nuclear structure can be of immense value because most of these pesticides have been reported to have carcinogenic, mutagenic and teratogenic properties.  相似文献   

12.
Turner  E. J.  Miller  D. C. 《Marine Biology》1991,111(1):55-64
Experiments were conducted in April–August 1989 on juvenileMercenaria mercenaria (L.) in an oscillatory water tunnel to simulate resuspension of bottom sediments by waves and to determine the effects of shortterm storm events on particle ingestion, pseudofeces production, and shell growth. Juveniles (mean length = 19.2 mm) were subjected to identical concentrations of algae in both low-flow, gentle waves (maximum velocity = 7 cm s–1) and high-velocity storm waves (maximum velocity = 22 cm s–1). Suspended sediment levels reached 193 mg 1–1 at 1 cm above the bed during storms. Shell growth decreased by a maximum of 38% during the storm when levels of phytoplankton were high (average cell concentration = 43 × 106 cells 1–1), and by 18% when phytoplankton levels were low (av cell conc = 6 × 106 cells 1–1). Orientation of clam siphons was not related to flow direction. Significantly more pseudofeces were produced when the clams were subjected to increased sediment resuspension under waves, and in troughs of sand ripples. The size of sediment grains ingested did not vary significantly among the flow treatments. The decrease in shell growth during storms may be due to a reduction in filtration rate coupled with a decrease in net energy gained from filtration due to costs of pseudofeces production. The magnitude of the decrease seems to be related to concentration of algae, water temperature, age of clams and sediment transport mode (bed load or suspended load). Thus, the interpretation of growth increments must be made in the context of these environmental variables.  相似文献   

13.
为了探讨海洋贝类对环境中雌激素的富集情况,采用液-液萃取和固相萃取方法提取了胶州湾李村河入海口蛤蜊、牡蛎和底泥中的雌酮(E1)、雌二醇(E2)、雌三醇(E3)和雌炔醇(EE2),并用GC-MS方法测定了上述4种物质的含量,此外还采用暴露实验方法研究了蛤蜊吸收底泥中雌激素物质的影响因素.测定结果显示,该水域中蛤蜊全组织中E1含量为0.45~5.20ng·g-1,E2含量为nd~4.34ng·g-1,E3和EE2未检出;牡蛎体内的E1、E2和E3含量分别为4.64~29.66、2.16~7.20和0.96~7.96ng·g-1,EE2未检出;底泥中E1、E2和E3含量分别为0.43~2.36、nd~0.59、0.52~1.13ng·g-1,EE2未检出.蛤蜊和牡蛎体内的雌激素物质含量高于其栖息的底泥.暴露实验结果显示,随着底泥中雌激素物质含量的增加或暴露时间增加,蛤蜊体内雌激素物质的含量增加,贝类可吸收并富集底泥中的雌激素物质.  相似文献   

14.
Adverse effects of diesel oil on microanatomical structure of the alimentary canal of O. nilotica were studied using SEM observations. The study revealed irregular arrangement of the stratified epithelial cells along with fragmentation of the normal concentric pattem of microridges of the same cells in buccopharynx and oesophagus. The excessive secretion of mucus of buccopharynx and oesophagus were the salient changes caused by diesel oil pollution. The destruction and degeneration of the mucosal folds of stomach and intestine along with their epithelial cells exhibited a concrete hyperactivity resulting in abundant' secretion of mucus over the microridges of the epithelial cells. In the intestinal region the columnar epithelial cells showed tumefaction and microvilli of the plasma membrane of epithelial cells get heavily damaged. Disarray of the microridges of epithelial cells, excessive secretions of mucus formation of even cell sheet were the most conspicuous changes in rectum. It was concluded that chronic exposure of diesel oil may hamper the absorption of the nutrients through alimentary canal resulting into ill-growth and production of the fish.  相似文献   

15.
The coastal saline soils, Kharlands, have great potential for their use in aquaculture. This study has been taken up to understand the limnology of the ponds in Kharland area for assessing their prawn culture potential. This study was carried out during September, 1999 to August, 2001. Each Kharland pond has an area of 0.045 hectare. During the study, depth of pond water was 47.7 to 120.0 cm, temperature varied from 25.7 to 34.5 degrees C; transparency from nil to 65.0 cm; specific conductivity from 1.78 to 94.5 microS.cm(-1); total dissolved solids from 0.89 to 27.55 ppt; pH 5.42 to 8.25; dissolved oxygen 1.6 to 8 mg.l(-1); free carbon dioxide 10.00 to 44.00 mg.l(-1); total alkalinity 5.00 to 142.00 mg.l(-1); salinity 0.45 to 39.55 ppt; total hardness 245.00 to 5945.00; calcium 56.05 to 1827.6; magnesium 110.74 to 4507.75 mg.l(-1); dissolved organic matter 1.45 to 9.68 mg.l(-1); ammonia 1.00-8.00 microg.l(-1); nitrite nil to 20.00 micro l(-1) and nitrate 7.5 to 17.5 microg.l(-1). These Kharland ponds are unique in physio-chemical characteristics during their seasonal cycle. From July to October, these ponds have nearly freshwater while from November to May pond water becomes saline. Thus, there is a great possibility of taking up monoculture of both the freshwater and brackish water prawns as well as polyculture of prawns and fishes in the Kharland ponds.  相似文献   

16.
多壁碳纳米管对水稻幼苗的植物毒性研究   总被引:1,自引:0,他引:1  
考察了浓度为10、50和100 mg·L~(-1)的多壁碳纳米管(MWCNTs)的植物毒性,通过测量水稻生长指数、根系氧化应激反应、细胞膜损伤和生理功能的变化,探索了其具体的毒性机制。将水稻幼苗暴露于不同浓度的MWCNTs悬浮液中培养10 d后,高浓度处理组(100 mg·L~(-1))中水稻幼苗地上部分和根系鲜重分别降低至对照组的87.6%±1.1%和69.2%±7.8%。对根系深入研究发现氧化应激反应和细胞膜的损伤主要出现在高浓度处理组,此时过氧化氢酶(CAT)活性由对照组的(8.8±1.6)U·mg-1prot(protein,蛋白质)增加至(16.3±2.8)U·mg-1prot,丙二醛(MDA)含量由对照组的(8.0±0.3)μmol·g-1FW(fresh weight,鲜重)增加至(15.1±1.4)μmol·g-1FW。然而,水稻根系的生化酶活性在低浓度(10 mg·L~(-1))时就开始明显降低。通过透射电镜(TEM)观察发现,MWCNTs颗粒分布在水稻幼苗根系细胞内,从而证实了MWCNTs能被植物细胞吸收。  相似文献   

17.
Ria Formosa Lagoon is the most important bivalve production region of the South Portuguese coast. However, the microbial contamination has been increasing in the northwest area of the lagoon. This study assesses the microbiological contamination of clams Ruditapes decussatus from the most contaminated area for 1 year period. Escherichia coli levels were weekly determined and related with variations in several environmental parameters: precipitation, atmospheric temperature, solar radiation, wind velocity, humidity and tide height. Highest E. coli levels in clams were associated with periods of heaviest rainfall and lowest temperature, mainly due to diffuse sources of faecal discharges. A seasonal trend was observed: microbial contamination in clams was lowest in summer, with highest temperatures, intense solar radiation and dry weather and higher in the remaining seasons, especially in winter due to the runoff of faecal contaminated waters. Several measurements not only to protect the quality of the lagoon, but also to protect public health were recommended. The most imperative will be to detect and extinguish the diffuse contamination sources. Otherwise it might be necessary to implement an interdiction period of bivalve harvesting after heavy rainfalls.  相似文献   

18.
The study deals with the toxicological impact of cadmium nanoparticles (Cd NPs) on Bacillus subtilis as a model Gram-positive bacterium. Cadmium oxide (CdO) NPs (~22 nm) and cadmium sulfide (CdS) NPs (~3 nm) were used in this study. Both the NPs were found to inhibit the cell viability of B. subtilis when added to the culture at mid-log phase, the viable cell number declined with increasing concentration of Cd NPs. At mid-log phase, 15 mg L?1 CdO NPs inhibited growth by ~50%, whereas at 30 mg L?1 growth completely ceased. Under the same conditions, CdS NPs inhibited growth by ~50% at a concentration of 8 mg L?1, and at 20 mg L?1 growth was completely retarded. The cells changed their morphological features to a filamentous form with increasing Cd NPs exposure time, leading to associated with clumping. NPs treated cells when stained with 4′, 6-diamino-2-phenylindole, showed filamentous multinucleated bead structure, suggesting irregularities in cell division. Increasing intracellular oxidative stress due to Cd NPs exposure might be one of the reasons for the cell morphological changes and toxicity in B. subtilis.  相似文献   

19.
The paper deals with the deleterious changes at ultrastructural level of the epithelial cells of gills of Cyprinus carpio communis Linn. upon exposure to 1/10th of LC50 of monocrotophos which is considered to be insignificant concentration from toxicological point of view. The gills of the fish are the primary corridor formolecularexchange between the internal milieu of a fish and its environment. Gills perform numerous functions such as oxygen uptake and CO2 excretion, osmoregulation, acid-basic balance, excretion of nitrogenous compounds and taste. Hazardous chemicals present in water may alter the morphology of the epithelial cells of gills of the fish, which may affect the process of diffusion of gases and ultimately the overall health of the fish. To prove this fact Cyprinus carpio communis Linn. was kept in water for 30 days having low concentration of 0.038 ppm (1\10th of LC50) of monocrotophos and an attempt was made to study the different types of degenerations produced in the epithelial cells of gills as compared to the normal epithelial cells of gills of this culturable fish using Scanning Electron Microscope (SEM) technique. The ultrastructural changes due to the toxic exposure at finer scale were thinning of microridges, upliftment of epithelial cells, development of hyperplasia, decrease in the density of mucous cells which are considered to be the first line of defence and total dystrophy of epithelial tissue. Thus, it is opined that a low concentration of monocrotophos has the potential to bring different type of degenerations at finer scale hence affecting the fish's health drastically and altering the fitness of the fish in water even having insignificant amount of this toxicant in the ambient water  相似文献   

20.
The present study was to evaluate heavy metal toxicity stress symptoms in fish blood during long-term exposure of sublethal concentration of copper sulphate (CuSO4). The effects of copper on various heamatological parameters were evaluated exposing Indian fresh water fish, Channa punctatus to a sub-lethal concentration of copper sulphate (0.36 mg l(-1)) for different periods. Exposure of fish to copper showed a significant decrease in the haemoglobin (Hb) content from 10.73 to 6.60%, red blood cells (RBC) from 2.86 to 1.84 x 10(6)/mm3 and packed cell volume (PCV) from 31.00 to 23.33% at the end of 45th day as compared to control. Whereas the white blood cells (WBC) increased from 60.00 to 92.48 x10(3)/mm3, clotting time (CT) from 27.66 to 43.00 second, erythrocyte sedimentation rate from 5.0 to 13.66 mm/hr and mean corpuscular volume from 108.11 to 126.85 cmu, significantly, with increase in exposure periods. Although mean corpuscular haemoglobin concentration (MCHC) and mean corpuscular haemoglobin (MCH) values showed significant increase during 15 and 30 days exposures, both the values were found significantly increased at the end of the experimental period. The differential leucocytes count (DLC) showed a significant increase in the populations of lymphocytes and eosinophils, whereas neutrophils, monocytes and basophiles were found decreased after exposure to copper.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号