角突网纹溞和蚤状溞作为泥鳅开口饵料的可行性研究

在水温（25±1）℃的条件下,以熟蛋黄为对照,研究了角突网纹溞（Ceriodaphnia cornuta）和蚤状溞（Daph-nia pulex）作为泥鳅（ Missgurnus arguillicaudatus）开口饵料的可行性。试验泥鳅为3日龄仔鱼,全长为（4.23±0.05） mm,体重为（1.21±0.01） mg,试验周期为20 d。结果显示：角突网纹溞组、蚤状溞组及蛋黄组泥鳅仔鱼的成活率分别为59.00％、38.67％和27.00％,三组之间的差异均达极显著水平;角突网纹溞组、蚤状溞组和对照组的泥鳅仔鱼全长分别为（26.43±1.96） mm、（28.30±7.64） mm和（12.74±0.15） mm,体重分别为（148.98±25.50） mg、（158.02±101.41） mg和（19.36±0.83） mg,两试验组间的全长和体重差异不显著,但均与对照组有极显著差异。结果表明,两种枝角类（尤其是角突网纹溞）作为泥鳅仔鱼的开口饵料,能较大幅度地提高泥鳅仔鱼的成活率,且可获得较大规格的鳅苗,在鳅苗的规模化人工繁育中具有较大的应用价值。     

The Use of a Daphnia magna Bioassay for Rapid Screening of Acute Intoxications with Insecticides in Dogs and Cats

Sudden death due to acute insecticide intoxications occurs frequently in dogs and cats. The absence of characteristic lesions at autopsy often renders post-mortem diagnosis dependent on the analysis of samples taken from the carcase at autopsy. In the present study, a bioassay utilizing Daphnia magna was proposed and tested as a rapid screening method for acute intoxications in dogs and cats. The bioassay was shown to be highly sensitive for detecting carbamate and organophosphate insecticides in the stomach contents. Generally, the mean survival time of the waterfleas in the control group was 5.17 h (SD = 1.24) and in the intoxicated group 1.32 h (SD = 1.49), during a 6 h observation period. If a cut-off is set at 4 h, this Daphnia bioassay gave 5.5% false negative results and 18.2% false positive results, using the results of toxicological analyses as a gold standard.     

有毒铜绿微囊藻对大型溞生长和繁殖的影响研究

用铜绿微囊藻有毒株DS和无毒株573喂养大型溞,观察微囊藻对虫体的生长和繁殖的影响。试验结果表明,有毒的微囊藻不仅明显延缓大型溞的生长,而且阻碍虫体的怀卵和发育,并造成幼体产出困难、导致大型溞死亡率升高。无毒微囊藻虽然不影响虫体的生存,但影响其怀卵量和幼体产出。因此单一使用微囊藻饲喂大型溞不能保持其种群良好地生长和繁殖。     

隆线溞夏卵胚胎发育过程中形态及蛋白质、氨基酸组成和含量的变化

系统观察了隆线夏卵的胚胎发育。根据胚胎外部形态学特征,将其胚胎发育分为卵期、长胚期、双复眼期和单复眼期四个主要时期,并采用生物化学方法测定和分析了隆线夏卵胚胎发育过程中蛋白质和氨基酸的组成和含量。实验得知,可溶性蛋白和氨基酸含量的变化趋势与隆线夏卵胚胎发育的特征密切相关,卵期可溶性蛋白和氨基酸含量呈下降趋势,而长胚期略有上升,但从双复眼期至胚胎准备孵化期间又持续下降。随着隆线夏卵胚胎的发育,可溶性蛋白的组成由大分子量的蛋白向小分子量的蛋白转化;在所有的氨基酸中谷氨酸的含量最高,必需氨基酸中亮氨酸的含量最高。结果表明,蛋白质和氨基酸是隆线胚胎发育过程中的主要营养物质,不仅用于胚胎发育组织和器官的构建,而且为胚胎发育提供能量。     

5种杀菌剂对3种水生生物的急性毒性与安全性评价

为评价吡唑醚菌酯、啶酰菌胺、嘧菌酯、戊唑醇和丙环唑5种杀菌剂对水生态的安全性,运用评价化学品对水生生物毒性的标准试验方法,测定了这5种杀菌剂对羊角月芽藻、大型溞和斑马鱼3种水生生物的急性毒性,并进行了安全性评价.结果表明,吡唑醚菌酯对大型溞48 h的EC50为0.0230 mg/L(a.i.),对斑马鱼96 h的LC50为0.0311 mg/L,均为剧毒;对羊角月芽藻72 h的EC50为0.451 mg/L,为中毒.啶酰菌胺对大型溞48 h的EC50为9.26mg/L,对斑马鱼96 h的LC50为2.90 mg/L,均为中毒;对羊角月芽藻72 h的EC50为13.1 mg/L,为低毒.嘧菌酯对羊角月芽藻72 h的EC50为0.165 mg/L,对大型溞48 h的EC50为0.221 mg/L,对斑马鱼96 h的LC50为0.817 mg/L,均为高毒.戊唑醇和丙环唑对羊角月芽藻72 h的EC50分别为1.95、0.772 mg/L,对大型溞48 h的EC50分别为4.83、3.88 mg/L,对斑马鱼96 h的LC50分别为4.66、2.47 mg/L,均为中毒.     

Evaluation of a Multi-species Test System for Assessing Acute and Chronic Toxicity of Sediments and Water to Aquatic Invertebrates: Effects of Pentachlorophenol on Daphnia magna and Chironomus prasinus (6 pp)

Background, Aims and Scope   Single-species toxicity tests are currently used as main tools for assessing effects in ecological risk assessments. Nevertheless, in higher-tier evaluations, alternative ecotoxicological methods can be required. Alternative methods should cover more realistic exposure conditions and/or additional species or endpoints. Water/sediment systems can be considered for covering additional exposure routes. A typical feature of water/sediment systems is the modification of exposure levels with time. The simultaneous exposure of different species within the same system can cover differences in sensitivity and relevance of exposure routes. The aim of this study was to develop a water/sediment test that could detect relevant effects on two selected species and explore the relevance of sediment and waterborne exposure routes. This alternative method may provide relevant information facilitating the design of microcosm and mesocosm studies.Methods   A multi-species water/sediment system was designed using two invertebrates: Chironomus prasinus a benthic detritivore invertebrate and Daphnia magna a pelagic filtering invertebrate was designed. Seven static water/sediments systems were built up: two controls and five treatments where sediments were spiked with NaPCP at nominal concentrations of 1.25, 2.5, 5, 10 and 20 mg/kg, respectively. Each system contained caged and free (unrestrained) Daphnia magna organisms to consider differences in the exposure route (through sediment and/or water column) and Chironomus prasinus organisms. Fate and partitioning of PCP within the water/sediment compartments were assessed. Acute (lethality) and chronic effects (reproduction) for Daphnia magna were monitored after 48 h and 16 days of exposure, respectively. Adult emergence and oviposition success of Chironomus prasinus were monitored at the end of test (16 days).Results and Discussion   Mortality and reproduction inhibition of Daphnia magna occurred at the two higher doses, corresponding to maximum measured PCP water concentrations of 1.95 and 0.746 mg/l, respectively. Chironomus prasinus was less sensitive to PCP than Daphnia magna. Concentrations inhibiting reproduction and provoking almost 100% adult mortality in D. magna only reduced slightly the emergence and reproduction of chironomids. The experimental design focussed on suitability of the system for assessing simultaneously assessing effects on D. magna and C. prasinus instead of calculations of toxicity endpoints for PCP. The results indicate that this experimental design can be useful to the field of sediment/aquatic toxicity testing, particularly through the comparison with single- species results. Assessment of relative contribution of two exposure routes for Daphnia magna and complementary chronic endpoints derived from two different species can be achieved. Another advantage is that differences in reproduction strategies of selected species (sexual vs. parthenogenetic) should permit one to detect mechanisms of action associated to with endocrine disrupters.Conclusion   The feasibility of a two-species test built-up in an artificial sediment/water system has been demonstrated. This experimental design represents a cost/effective test which can assess effects through water and sediment pathways and incorporates several relevant chronic endpoints in a single assay. Recommendation and Outlook   By building on the experience gained, improvements for further test designs are discussed. Test validation with a set of model chemicals will contribute to address the effectiveness of the test developed as comparing compared to single- species tests.     

氯霉素对大型溞的急性和慢性毒性效应

[目的]评价氯霉素对水生生物的生态风险。[方法]以大型溞为研究对象,探讨不同浓度氯霉素对大型溞急性和慢性毒性。[结果]急性毒性试验结果表明,氯霉素对大型溞的48 h-EC50值为175.846 mg/L,属于低等毒性。21 d慢性毒性试验中各浓度处理对大型溞生长繁殖相关指标有不同程度的影响,且子代出现了不同程度的畸形现象。[结论]该研究结果为氯霉素水生生态毒性评价提供理论依据。     

富勒烯对大型蚤的急性毒性和慢性毒性效应

为深入理解富勒烯(Fullerene,nC_(60))的水生生态毒理效应,以模式动物大型蚤(Daphnia magna)为研究对象,研究nC_(60)对大型蚤的48 h和72 h急性毒性效应以及21 d慢性毒性效应。结果表明,急性暴露下,nC_(60)对大型蚤的48 h半抑制浓度(EC_(50))和半致死浓度(LC_(50))分别为25.3 mg·L~(-1)和28.5 mg·L~(-1),72 h的EC_(50)和LC_(50)分别为14.9 mg·L~(-1)和16.3 mg·L~(-1),且大型蚤的跳跃频率和心跳频率随着在nC_(60)中暴露时间的延长先增加后减少;慢性暴露下,1 mg·L~(-1)的nC_(60)即可对大型蚤的繁殖产生影响,21 d内总产蚤数和平均产蚤数分别为53.3个和0.3个,与对照相比明显降低。研究结果表明,无论急性还是慢性暴露下,nC_(60)均显著抑制大型蚤的生长和繁殖,其水生生态毒性不容忽视。     

不同密度的大型溞对浮游植物群落的影响

为了了解在不滤出原水中浮游动物的条件下,不同密度的大型溞(Daphnia magna)对浮游植物的直接和间接影响,以及控藻效果最佳的大型溞添加密度。于2016年5月进行了大型溞添加模拟实验。实验设一个对照组(C0)和C1、C2、C3、C4 4个处理组,大型溞的添加密度分别为0、5、15、25、50 ind/L,每个实验组设3个平行,实验期10 d。结果显示:(1)与对照组相比,低密度处理组(C1和C2)和高密度处理组(C3和C4)均可抑制藻类密度,后者最为明显。(2)大型溞摄食优先选择绿藻和粒径介于20~30μm的藻类。(3)大型溞对原水中的颈沟基合溞(Bosminopsis deitersi)、长肢秀体溞(Diaphanosoma leuchtenbergianum)、剑水蚤、轮虫和原生动物均有抑制作用,在本文所设密度范围内,添加的密度越大抑制作用越强(除原生动物),从而间接的影响浮游植物群落。(4)当添加的大型溞密度为25 ind/L时,控藻的效果最佳,实验4 d后,藻类密度降至最低,约下降至原来的24.9%。     

季铵盐和有机硅助剂对啶虫脒杀虫活性及水生生物毒性的影响

分别以浸渍法和相加指数法,评价了5种季铵盐助剂和3种有机硅助剂分别与啶虫脒混合使用时对苹果黄蚜Aphis citricola的联合作用,以及对两种非靶标水生环境生物大型溞Daphnia magna和斑马鱼Brachydonio rerio的毒性。结果表明,有机硅助剂和季铵盐助剂对啶虫脒防治蚜虫具有明显的增效作用,且silwet 618的增效倍数高达210.2。环境毒性试验结果表明:啶虫脒对两种水生生物均为低毒;供试季铵盐和有机硅助剂对大型溞的单一毒性均为剧毒,季铵盐助剂对斑马鱼为高毒,而有机硅助剂对斑马鱼为中毒。与农药联合作用测定结果表明:有机硅助剂对两种水生生物均表现为增毒作用;而5种季铵盐助剂除十四烷基二甲基苄基氯化铵（1427）对大型溞表现为增毒作用外,其他4种对两种水生生物均呈现不同程度的拮抗作用。此外,季铵盐和有机硅助剂还可以显著降低清水的表面张力（由清水的74.37 mN/m降为20.50~40.07 mN/m）,提高叶片上的最大持留量（由清水的1.54 μg/cm2提高到2.39~4.34 μg/cm2）。因此,使用季铵盐和有机硅助剂作为增效剂时应考虑其对水生生物的毒性,其中季铵盐助剂对环境生物的潜在威胁更小。