甲基汞和硒在鲤鱼组织中的蓄积及对肝胰脏中某些元素含量的影响

在20±2℃测定鲤鱼在28天受甲基汞、硒接触期间,肌肉、脑和肝胰脏中蓄积的汞,肌肉中蓄积的硒。用扫描电子显微镜-X射线能谱仪测定肝胰脏中Na,P,K,S,Cl,Ca等元素的含量与汞吸收量之间的关系。试验结果说明汞与硒之间存在拮抗作用。     

2,4-DNT对鲤鱼的急性和亚急性毒性

实验测定２,４－ＤＮＴ对鲤鱼的急生和亚急性亚急性试验经１．６４０,３．２８０,４．９１９,６．５５９,９．１０９ｍｇ．Ｌ＾－１２,４－ＤＮＴ暴露３６ｄ,在１５－１９℃下,２４,４８,７２,９６ｈ的ＬＣ５０值分别为３０．７８,２７．２５,８４．２４,９６ｍｇ．Ｌ＾－１。     

水生动植物联合作用净化不同富营养化景观水体研究

选择睡莲(Nymphaeatetragona)、轮叶黑藻(Hydrillaverticillata)、鲢鱼(Aristichthysnobilis)和中华圆田螺(Cipangopludinachinensis)为实验对象,设置富营养和极富营养两种浓度梯度,通过室外试验探讨不同动植物及其组合对两种浓度水平中总氮(TN)、总磷(TP)及叶绿素a(Chl-a)的净化效果。结果表明,在富营养和极富营养水平中,均以睡莲和黑藻组合对TN和TP的去除效果最好,TN去除率分别为66.4%和42.3%,TP去除率分别为97.1%和89.6%,TP去除率分别高出相应对照组53.2和35.3个百分点;鲢鱼和中华圆田螺的加入会引起TN和TP的升高,但是由鲢鱼、中华圆田螺、睡莲和黑藻组成的组合对藻类的抑制效果最好,其Chl-a含量始终保持最低含量,日均值不超过1.16 mg/m3。因此,鲢鱼、中华圆田螺、睡莲和黑藻联合作用对富营养化水体具有明显的净化效果,其协同作用可为景观湖泊富营养化控制提供理论基础和科学依据。     

三峡水库蓄水初期鲤鱼重金属富集特征及健康风险评价

于2011-2012年在三峡库区干流水域及7条典型支流中采集鲤鱼样品,通过测定鱼体肌肉组织中Cr、Cd、As、Pb、Ni、Cu和Zn等7种重金属含量,分析了三峡库区蓄水后的鱼体重金属污染水平、各金属元素之间的相关性及在库区各水域的分布特征,并利用目标危险系数(THQ)对库区居民通过食用鱼类摄入重金属的健康风险进行了评价.结果显示,所有鱼类样品中均检测出这7种重金属,但含量低于国家规定的卫生健康标准.不同重金属在鱼体肌肉中差异明显,Zn的平均含量最高(5.88 mg·kg-1),Cd平均含量最低(0.013 mg·kg-1).所有7种重金属可分为4类,式中,Cr和Cu,Pb和As相关系数较大.与库区外其他水域相比,三峡水库中鱼体重金属含量处于较低水平,且在蓄水后未发生显著变化.受到水位升高和悬浮物沉降的影响,库区内干流鱼体中大部分重金属含量变化趋势为从库尾的洛碛向库中的巫山递减.THQ法评价结果认为,食用库区鱼类健康风险较低.     

Effect of sub-acute exposure to TiO2 nanoparticles on oxidative stress and histopathological changes in Juvenile Carp （Cyprinus carpio）

Increasing application of nanotechnology highlights the need to clarify and understand nanotoxicity. Mammalian and in vitro studies have raised concerns about the toxicity of titanium dioxide nanoparticles (TiO₂-NPs), but there are limited data on ecotoxicity to aquatic organisms. In this work, the sub-acute toxicity of TiO₂-NPs to carp (Cyprinus carpio) was assessed. Superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) activities and lipid peroxidation (LPO) levels in liver, gill and brain tissues of carps varied with concentration of TiO₂-NPs suspensions and exposure time (up to 8 d). As a result, 100 and 200 mg/L TiO₂-NPs caused statistically significant decrease in SOD, CAT and POD activities and significant increase in LPO levels in tissues (P < 0.05), suggesting that the fish exposed to these two concentrations of TiO₂-NPs suffered from the oxidative stress. The extent of depletion of antioxidant enzymes activities and the elevation of LPO in the liver was the greatest, indicating that the liver might be the most susceptible organ to TiO₂-NPs exposure. In addition, carps had gill pathologies including edema and thickening of gill lamellae as well as gill filaments, and liver pathologies including necrotic and apoptosis hepatocytes after exposed to 100 and 200 mg/L TiO₂-NPs for 20 d. These results indicated a potential risk from TiO₂-NPs released into the aqueous environment.     

草鱼在2-硝基芴试验液中暴露后鳃组织结构变化的初步研究

用电镜观察的方法研究具有直接致突变性和致癌性的化合物－２硝基芴对草鱼鳃组织结构的影响,结果表明,２－硝基芴对鳃组织有明显的损伤,主要包括鳃小片的肿大和出现大量的泌氯细胞,并在作用１０ｄ时观察到上皮细胞死亡。     

单甲脒对鲤鱼的急性和亚急性毒性

为制定渔业水质标准的需要,用静态实验的方法测定了单甲脒对鲤鱼的急性和亚急性毒性。亚急性试验经13.34、6.67、3.33、1.67、0.83、0.42mg/L单甲脒暴露35天。在18～21℃下,24、48、72、96h的LC₅₀值分别为33.47、31.62、26.38、25.84mg/L。亚急性试验中,根据单甲脒对鲤鱼生长和脑、肝、肾、鳃ATPase活力的影响,求得单甲脒的最大允许毒物浓度为0.42～0.83mg/L。     

Effects of subchronic exposure to carbofuran on antioxidant defence system and malondialdehyde levels in common carp (Cyprinus carpio L.)

The present study focused on the assessment of oxidative stress induction by pesticides such as carbamates which are widely used as insecticides and nematicides and contaminate aquatic ecosystems on certain biomarkers in liver of common carp (Cyprinus carpio L.). Biomarkers selected for stress monitoring were malondialdehyde (MDA), an index of lipid peroxidation, and antioxidant defence system enzymes, mainly catalase (CAT), glutathione reductase (GR), and glutathione-S-transferase (GST) activities in liver of fish exposed to 0, 10, 50, or 100?µg?L^?1 of carbofuran for 4, 15, or 30 days. Oxidative stress was found in liver of common carp exposed to carbofuran which was manifested by a decrease in CAT and GR activities after 4 and 30 days of exposure. An adaptive response was probably produced since at day 15 no modifications in the CAT activity and increased GR activity were observed. In addition, a decrease in MDA content with the highest concentration of carbofuran used was found after 30 days of exposure. However, no significant changes were found in GST activity showing a varied response. The results concerning oxidative and antioxidant profiles indicate that subchronic exposure to the insecticide carbofuran is capable of inducing oxidative stress in fish.     

Toxic effects of 2,4‐D herbicide on fish

Abstract

Acute and subacute 2,4‐D toxicity to carp (Cyprinus carpio L.) were investigated. Acute toxicity (LC‐ 50) was investigated in semi‐static test during a 24, 48, and 96‐ hours exposition. Subacute toxicity was investigated by exposing fish to different 2,4,‐D concentrations (150, 200, and 250 mg/L) for 14 days. Biochemical and morphological changes in certain organs and tissues were investigated.

LC‐ 50 values at 24 hours exposure was 310.0 mg/L, 295.0 mg/L for 48 hours, and 270.0 mg/L for 96 hours exposure.

Subacute toxicity tests show that 2,4‐D induce changes in the enzyme activities (AP, GOT, GPT) and morphological changes in the gills, liver and kidneys, but changes are of limited biological importance.     

亚硝酸盐氮对草鱼种耗氧率的影响及适应性研究

通过测定全血红蛋白和高铁血红蛋白及耗氧率，研究了草鱼种在NO－N作用下的生理变化和对NO－N的适应性,结果表明：ρ（NO－N）在O～4mg·L－1范围内可使草鱼种耗氧率增加，并于1mp·L－1和4mg·L－1处出现峰值和次峰值；经暴露处理的鱼种在恢复21d后，显示出对NO-N的适应性．