Ca^2＋、Mg^2＋对凡纳滨对虾存活及生长的影响

通过单因子静态急性毒性试验和正交设计法,研究水环境中Ca~(2 )、Mg~(2 )、Ca~(2 ) Mg~(2 )总量及Ca~(2 )/Mg~(2 )比值对凡纳滨对虾存活及生长的影响。结果表明:(1)凡纳滨对虾48h的Ca~(2 )的LC_50为407.38mg·L~(-1)、Mg~(2 )的LC_(50)为741.31mg·L~(-1)。(2)在Ca~(2 )/Mg~(2 )比值为1:10时,对凡纳滨对虾生存没有影响;(3)凡纳滨对虾的生长与Ca~(2 )浓度有密切关系,其值过高或过低均会影响凡纳滨对虾的生长;在Ca~(2 )/Mg~(2 )比值为1:3时,凡纳滨对虾生长和存活率随着Ca~(2 ) Mg~(2 )质量浓度的增加而上升,但达到一定质量浓度后,又随着Ca~(2 ) Mg~(2 )质量浓度的继续增加而下降。     

Three different levels of dietary vitamin D3 fed to first-feeding fry of Atlantic salmon (Salmo salar L.): effect on growth, mortality, calcium content and bone formation

Atlantic salmon ( Salmo salar L.) fry were reared on a fishmeal-based diet with three different levels of vitamin D₃ (0.2, 5 and 57 mg vitamin D₃ kg^–1 feed, ww) from first-feeding for 14 weeks. No significant differences were recorded in weight, length, specific growth rate, mortality, or kidney calcium concentration between the different dietary groups. No skeletal malformations or histopathological changes were recorded in any of the dietary groups. These results suggest Atlantic salmon fry to be highly tolerant of megadoses of vitamin D₃ over a limited period of time.     

元素磷对鱼类生化毒性影响的研究

通过对含有元素磷的水体中鱼类的血清胆碱酯酶和三磷酸腺苷(ATP)酶活性的测定,发现元素磷对上述两类酶的活性有一定的抑制作用。当抑制率为40%～70%时,即可导致鱼类亚急性中毒死亡。结果表明:元素磷不但是一种剧毒物质,能引起鱼类的急性中毒,而且是一种稳定的可积累的毒物,它能破坏鱼类的肝细胞,抑制正常代谢,造成神经毒性,以致引起鱼类的亚急性和慢性中毒死亡。     

Determination of a tissue and sediment threshold for tributyltin to protect prey species of juvenile salmonids listed under the US Endangered Species Act

• 1. The purpose of this report is to determine the concentrations of tributyltin in sediments that would be protective against adverse effects on prey species of salmonids listed under the US Endangered Species Act.
• 2. Two approaches for determining adverse sediment concentrations due to tributyltin (TBT) contamination are presented here. The first is the equilibrium partitioning (EqP) approach, which relies on a sediment‐water partition coefficient and toxicological data for water exposures. The EqP approach utilizes the large water quality database that has been generated over the last two decades for TBT and provides strong evidence for adverse effects at low exposure concentrations.
• 3. The second approach involves determination of a TBT tissue residue that is considered harmful for most species, which is then used to predict the sediment concentration that would likely produce this adverse tissue concentration.
• 4. Both approaches are presented here because they generally support each other but based on the information presented below, and the inherent difficulty in measuring porewater concentrations, the tissue residue approach is the recommended method for determining adverse sediment concentrations.
• 5. Using this analysis, the protective sediment concentration for TBT proposed here is 6000 ng g^?1organic carbon. Direct effects are not expected on salmonids at this sediment concentration because of their relatively short residence time in the estuary, general lack of interaction with sediment, and relatively high metabolic capacity. This concentration may ensure adequate abundance of salmonid prey species; however, it may not be low enough for the protection of sensitive benthic species.

Published in 2002 by John Wiley & Sons, Ltd.     

Acute Toxicity of Synthetic Pyrethroid Cypermethrin on the Common Carp (<Emphasis Type="Italic">Cyprinus carpio</Emphasis> L.) Embryos and Larvae

In this study, the toxic effects on the embryos and larvae of the common carp were used as a model to investigate the synthetic pyrethroid pesticide, cypermethrin, which contaminates aquatic ecosystems. Data obtained from the cypermethrin acute toxicity tests were evaluated using the Probit Analysis Statistical Method. The control and eight test experiments were repeated five times. The number of dead embryos significantly increased in response to cypermethrin concentrations 0.0001, 0.001, 0.01, 0.1, 1, 2, 4 and 8 μg l⁻¹ (p<0.05 for each case). The 48 h LC₅₀ value (with 95% confidence limits) of cypermethrin for common carp embryos was estimated at 0.909 (0.256–5.074) μg l⁻¹. Dose–response decreases in hatching success were recorded as 87.4, 85.0, 80.2, 71.4, 56.3, 48.6, 38.8 and 23.5%, respectively. The lowest concentration of cypermethrin (0.0001 μg l⁻¹) produced a significant increase in the number of dead larvae compared to the control group (p<0.05). The number of dead larvae significantly increased with increasing cypermethrin concentrations exposed for 1–96 h (p<0.05). The highest concentration (8 μg l⁻¹) showed the highest larvae mortality. The 96 h LC₅₀ value (with 95% confidence limits) of cypermethrin for common carp larvae was estimated at 0.809 (0.530–1.308) μg l⁻¹. The results of the study suggest that low levels of cypermethrin in the aquatic environment may have a significant effect on the reproduction and development of carp.     

硫醚沙星等四种药物对泥鳅的急性毒性试验

采用生物毒性试验的方法,在水温(22±1)℃条件下,用硫醚沙星、溴氯海因、指环清、季氨168、四种药物对泥鳅进行毒性试验,结果表明硫醚沙星24hLC50为167.72mg/L,安全浓度为39.745mg/L;溴氯海因24hLC50为116.6mg/L,安全浓度为50.20mg/L;指环清24hLC50为30mg/L,安全浓度为5.23mg/L;季氨168的24hLC50为60.56mg/L,安全浓度为10.37mg/L;建议指环清不能做泥鳅的治疗药物,季氨168要谨慎使用,溴氯海因及硫醚沙星可以作为泥鳅的治疗药物。     

玉米赤霉烯酮的生殖毒性研究进展

玉米赤霉烯酮是一种特殊毒性的生物毒素,它的强雌激素样作用对动物机体的伤害很大,不仅引起动物流产、死胎、低产仔率等生殖机能异常,还可以导致繁殖功能下降、不育、畸形等.已有研究表明,ZEA对肝脏、肾脏、生殖系统和免疫系统产生明显的损伤,对细胞和遗传性也有毒性作用.目前,虽然国内外学者做了大量的研究,来揭示玉米赤霉烯酮损害机体生殖功能的机制,但关于它影响机体的生殖性能更详尽的机制还亟待进一步的研究.文章主要针对玉米赤霉烯酮的生殖毒性进行了综述,总结出ZEA对生殖系统的毒性机制,从而为临床预防及治疗繁殖疾病提供理论依据.     

不同毒力传染性法氏囊病病毒衣壳蛋白酵母双杂交诱饵载体的构建及鉴定简

传染性法氏囊病病毒（infectious bursal disease virus,IBDV）毒株Gx（超强毒株）、F9（中等毒力毒株）、Gt（弱毒株）遗传背景高度相似,但生物学性状差异显著。为研究不同毒力毒株与宿主细胞相互作用的分子细节,本研究将IBDV Gx、F9、Gt毒株的衣壳蛋白VP2基因克隆入pGBKT7载体,分别构建了诱饵载体pGBGxVP2、pGBF9VP2和pGBGtVP2。经Matchmaker Gold Yeast Two-hybrid System验证,结果显示所构建的3个诱饵载体均无自激活作用,对酵母细胞无毒性作用。本研究为利用酵母双杂交系统深入研究IBDV与宿主相互作用奠定了基础。     

三种有毒物质对文蛤的毒性试验

在常温和静水条件下，用通常的生物毒性试验方法进行了Ｈ２Ｓ、Ｚｎ、ＮＨ３对文蛤的急性毒性试验，求出了它们对３．６０￣３．７４厘米体长文蛤的半致死浓度和安全浓度，为江苏沿海文蛤大批死亡的原因从侧面提供了分析的依据。     

氰戊菊酯对金鱼的急性毒性试验及残留测定

研究结果表明,氰戊菊酯对金鱼的24,48,72,96h的半致死质量浓度分别为73 1,24 0,20 7,12 5μg/L,氰戊菊酯对金鱼的毒性极大,并有十分明显的时间效应。金鱼对氰戊菊酯的富集系数很大,可达1×104～1×105,且肝和鳃的富集能力比肌肉要大。