灭虫精对西施舌幼贝的毒性试验

在静水条件下,进行灭虫精对西施舌幼贝的毒性试验,试验结果显示:灭虫精对西施舌幼贝24 h致死浓度LC100为400 ms／L,半数致死浓度LC100为250 mg/L,安全浓度为2．50mg／L;48h致死浓度为260 mg／L,半数致死浓度LC50为224ms／L,安全浓度为2．24mg／L。灭虫精用于西施舌人工育苗过程中桡足类等敌害生物防治,具有较强的可用性。根据试验结果,建议使用2 mg／L浓度的灭虫精进行防治,可达到显著效果。     

敌百虫和伊维菌素对近邻剑水蚤的急性毒性

鱼苗孵化用水经常会滋生桡足类,严重影响育苗的成活率。本文通过水生生物急性毒性试验方法,研究敌百虫和伊维菌素对淡水常见桡足类近邻剑水蚤（Cyclops vicinus）的急性毒性。根据预试验的结果,敌百虫浓度梯度设置为0.3、0.6、1.2、2.4、4.8 mg/L,伊维菌素浓度梯度设置为0.01、0.04、0.16、0.64、2.56μg/L。每个浓度组设置3个平行,每个平行放10只桡足类,试验在20℃光照培养箱中进行。结果表明,敌百虫对桡足类的24 h LC50和48 h LC50分别为1.862、1.183 mg/L,而伊维菌素对桡足类的24 h LC50和48 h LC50分别为0.404μg/L、0.1644μg/L。伊维菌素的毒性远远大于敌百虫,生产上选用伊维菌素效果更好。与此同时,敌百虫和伊维菌素对桡足类的安全浓度分别为0.1432 mg/L、0.00816μg/L,可以为生物监测环境农药污染提供重要依据。     

西施舌的食谱分析

为了提高西施舌（Coelomactra antiquata）种苗和人工养殖的生长率与成活率,以人工培育的西施舌稚贝和自然海区采捕的成贝为材料,采用人工投饵试验观察与镜检胃含物方法,对西施舌的食谱进行分析,结果表明：西施舌的稚贝除幼体发育阶段摄食超微型单细胞藻类外,还摄食个体大小为20～60μm的直链藻（Melosira spp．）、条纹小环藻（Cyclotella striam）、库氏园筛藻（Coscinodiscus kiitzngii）、小形园筛藻（C．minor）、小形舟形藻（Navicula Parva）、柔软舟形藻（N．mollis）、盾形舟形藻（N．scutiformis）、颗粒菱形藻（Nitzschia granulata）、碎片菱形藻（N．frustulum）、琴式菱形藻（N．panduriformis）、盾形卵形藻（Cocconeis scutellum）、双标胸隔藻（Mastogloia binotata）、施氏双壁藻（Diploneis schmidtii）等微型浮游硅藻及底栖硅藻。成体西施舌的食物以硅藻为主,计有35属114种。其中,直链藻、小环藻、园筛藻、舟形藻、菱形藻、辐裥藻（Actinoptychus sp．）、三角藻（Trlceretium sp．）、脆杆藻（Fragilaria sp．）、斑条藻（Grammatophora sp．）、褶盘藻（Frybioptychus sp．）、马鞍藻（Campylodiscussp．）、盒形藻（Biddulphia sp．）和双眉藻（Amphora sp．）等13属占优势。此外,还摄食单细胞绿藻、甲藻以及原生动物,小型甲壳动物和蔓足类的六肢幼虫及有机碎屑。     

河蟹土池生态育苗中敌害生物控制的实验室试验

文章对河蟹土池生态育苗中的敌害生物的控制进行实验室试验研究 ,结果表明 :漂白粉可有效控制敌害生物 ,4mg/ L有效氯即可杀灭沙蚕幼体和桡足类 ;划蝽对敌百虫较敏感 ,浓度为 0 .8mg/ L 时 ,1 2 h后全部致死 ;甲醛浓度为 0 .8m L/ L 时 ,1 2 h后全部致死划蝽 ;由小球藻配制的敌百虫液 ,浓度为 2 .0 mg/ L时 ,1 2 h后使划蝽全部致死 ,其杀死划蝽浓度明显高于由消毒海水配制的敌百虫液 ,说明小球藻液削弱敌百虫毒性效果明显。     

鳗弧菌灭活疫苗对杂交鲟的免疫效果初探

以0.5%的甲醛溶液为灭活剂,制备鳗弧菌灭活疫苗,经过无菌和安全试验后,按照2 m L/尾的剂量,通过腹腔注射途径注射浓度为1.78×108cfu/m L的鳗弧菌灭活疫苗对杂交鲟进行免疫;对照组用同等剂量生理盐水处理。免疫7 d后,对试验鱼进行鳗弧菌活菌攻毒。攻毒试验7 d后,计算疫苗的免疫保护率。结果表明,在实验室条件下,0.5%甲醛灭活的鳗弧菌疫苗对杂交鲟安全,免疫保护率为80%。     

敌百虫对黄河鲤鱼的急性毒性研究及安全评价

为了弄清楚敌百虫对黄河鲤鱼的急性毒性浓度,在常温条件下用80%的敌百虫(生产制品)对黄河鲤鱼进行急性毒性试验,试验分别设置6个浓度梯度:500 mg/L、601 mg/L、721 mg/L、866 mg/L、1 041 mg/L、1 250 mg/L,观察不同时间的半致死浓度并计算安全浓度。结果表明:黄河鲤鱼对敌百虫24 h、48 h、72 h、96 h的半致死浓度(LC50)分别为818.7 mg/L、774.7 mg/L、719.8 mg/L、719.8 mg/L;安全浓度为208.10 mg/L。     

西施舌大规格苗种培育技术研究

为促进西施舌大规格种苗生产规模化,于2001年7月8日~11月8日,在室内循环流水的条件下,采用底播和塑料筐养殖的方法,对西施舌幼苗平均体长为8.63 mm,培养成体长30 mm以上的大规格苗进行了比较研究。结果表明,经过123 d的循环流水养殖,底播养殖的西施舌幼苗日平均体长增长、体重增长和成活率分别为0.188 mm0、.044 g和88.20%;而塑料筐养殖的西施舌幼苗分别为0.206 mm0、.048 g和92.15%,说明循环流水培养西施舌幼苗的效果显著,具有应用价值。     

两种药物对白甲鱼幼鱼的急性毒性试验

在水温为(22±2)℃,pH值7.5~8.0,DO值为14.3 mg/L的条件下,研究甲醛、苯扎溴铵对白甲鱼幼鱼的急性毒性作用。结果:甲醛对白甲鱼幼鱼24、48、72、96 h的半数致死浓度(LC50)分别为66.99、49.32、46.56、43.95 mg/L,安全质量浓度(SC)为4.40 mg/L;苯扎溴铵对白甲鱼幼鱼24、48、72、96 h的LC50分别为83.18、81.28、77.63、63.10 mg/L,SC为6.31mg/L。甲醛的安全质量浓度属于常规用量范围,可作为浸泡剂对白甲鱼进行病害防治;苯扎溴铵对白甲鱼幼鱼属中毒药物。     

改性食用菌菌糠对重金属离子的吸附特性研究

为了开发利用廉价生物吸附剂并应用于重金属污染废水的处理,对食用菌菌糠进行了表面改性并研究了改性前后食用菌菌糠对Pb2+和Zn2+的吸附特性,调查了污水pH、重金属初始浓度、吸附剂用量、吸附时间和温度对其吸附性能的影响。结果表明,食用菌菌糠吸附剂用量分别为16g/L和12g/L时,pH值分别为5和6、初始重金属浓度为20mg/L、吸附时间为3h、25℃条件下,达到了最大吸附量,对Pb2+和Zn2+的去除率分别达到92.79%和88.96%,处理后的Pb2+和Zn2+浓度分别为1.442mg/L和2.208mg/L,接近污水综合排放标准(GB8978-1996)中的排放浓度1mg/L和2mg/L。食用菌菌糠对Pb2+和Zn2+的吸附等温线符合Fleundlich模式。     

地图鱼对八种常用鱼药的敏感性试验

体长3－5cm的地图鱼对八种常用鱼药的敏感性强度为：孔雀石绿＜敌百虫＞甲醛＞硝酸亚汞＞硫酸铜硫酸亚铁合剂（5：2）＞强氯精＞漂白粉＞食盐,各种药物对地图鱼的安全浓度依此次序分别为：0.013,0.035,1.74,0.13,0.78,0.39,1,6,3395ml/L。     

Diagnosis of nitrate toxicosis in cattle, using biological fluids and a rapid ion chromatographic method

An ion chromatographic method was used to simultaneously determine nitrate and nitrite ions in biological samples. Ultrafiltration was used to produce a protein-free filtrate. Chloride interferences were eliminated by precipitation as the silver salt. Detection limits and average recoveries were 0.5 mg/L and 102% for nitrate and 0.2 mg/L and 78% for nitrite, respectively. Nitrate concentration was 2.1 +/- 1.8 mg/L and 4.9 +/- 0.8 mg/L in serum and ocular fluid of healthy cattle, respectively; nitrite was not detected. A severe case of nitrate poisoning in cattle was described and used to study the concentrations of nitrate and nitrite in samples obtained under natural conditions. Nitrate concentration of acutely poisoned cattle was 35% lower in ocular fluid at 158.1 +/- 51.4 mg/L, than in serum at 256.3 +/- 113.4 mg/L. Nitrite was not detected, because of the long processing time (greater than 3 hours) required for samples obtained in the field. A gradual decrease in ocular fluid nitrate of 29.4% at 24 hours, 25.9% at 36 hours, 51.6% at 48 hours, and 73.2% at 60 hours was observed; however, concentrations remained diagnostically significant (73.2 mg/L) 60 hours after death. Twenty-four hours after poisoning, the serum nitrate concentration of severely ill (52.7 +/- 51.9 mg/L) and moderately affected (12.4 +/- 5.7 mg/L) cattle that survived was indicative of the severity of clinical signs previously observed. Nitrate in serum and ocular fluid was stable in samples stored for 24 hours at 23 C, 1 week at 4 C, and 1 month at -20 C.     

Early pathophysiologic feature of arthropathy in juvenile dogs induced by ofloxacin, a quinolone antimicrobial agent

Arthropathy in dogs induced by ofloxacin, a quinolone antimicrobial agent, was pathophysiologically investigated. In the in vivo studies, ofloxacin was administered orally once or twice at 20 mg/kg/day to male juvenile (3-month-old, n=3) or adult (36-month-old, n=2) dogs, and the humeral and femoral heads were examined pathologically. Unlike adult dogs, fluid-filled vesicles were macroscopically observed on the articular surfaces of one juvenile dog 24 hours after a single treatment with ofloxacin. These lesions were seen in all juvenile dogs by twice dosing. Microscopically, fissures or cavity formations in the middle zone of the articular cartilage were noted only in juvenile dogs. Furthermore, the cartilage matrix from the abnormal area to the articular surface showed a decreased safranin-O staining intensity, suggesting proteoglycan depletion. Ultrastructurally, chondrocytes in the middle zone of juvenile dogs displayed dilatation of the cisternae in the rough endoplasmic reticulum as an initial hallmark. In the in vitro studies, chondrocytes isolated from the articular cartilage of naive juvenile dogs were exposed to ofloxacin at 6.3-100 microg/ml for 24 hours. Although no changes were noted in the deoxyribonucleic acid synthesis, protein synthesis, or proteoglycan release at concentrations of up to 100 microg/ml, the proteoglycan synthesis was evidently decreased in a dose-dependent manner from 12.5 microg/ml. The results obtained suggest that the inhibitory action of ofloxacin on proteoglycan syntheses in the chondrocytes may largely contribute to the early morphologic features in the articular cartilage of the juvenile dog.     

Pharmacokinetics of once-daily amikacin in healthy foals and therapeutic drug monitoring in hospitalized equine neonates

The objectives of this study were to investigate the pharmacokinetics of once-daily amikacin in healthy neonates, to determine amikacin concentrations in hospitalized foals, and to determine the minimum inhibitory concentrations (MICs) of amikacin against gram-negative isolates from blood cultures in septic foals. Median half-life, clearance, and volume of distribution of amikacin in healthy 2- to 3-day-old foals after administration of an intravenous bolus of amikacin (25 mg/kg) were 5.07 hours (4.86-5.45 hours), 1.82 mL/min/kg (1.35-1.97 mL/min/kg), and 0.785 L/kg (0.638-0.862 L/kg), respectively. Statistically significant (P <.05) decreases in area under the curve (14% decrease), mean residence time (19% decrease), and C24h plasma amikacin concentrations (29% decrease) occurred between days 2-3 and 10-11. Plasma amikacin concentrations in healthy foals at 0.5 hours (C0.5h) were significantly higher (P = .02) than those of hospitalized foals. Sepsis, prematurity, and hypoxemia did not alter amikacin concentrations. The MIC at which 90% of all gram-negative isolates from equine neonatal blood cultures were inhibited by amikacin was 4 microg/mL, suggesting that amikacin C0.5h of 40 microg/mL should be targeted to achieve a maximum serum concentration to MIC ratio of 10:1. The proportion of foals with C0.5h 40 microg/mL was significantly higher (P < .0001) in hospitalized foals receiving a dose of amikacin at 25 mg/kg (22/24 or 92%) than in foals receiving a dose at 21 mg/kg (9/25 or 36%), whereas no difference was found in the proportion of foals with C24h concentrations > or = 3 microg/mL between the 2 groups. An initial dose at 25 mg/kg is recommended for once-daily amikacin in equine neonates.     

苜蓿花药培养及倍性鉴定

在不同低温预处理时间,不同培养基和不同激素组合下进行了苜蓿花药培养实验。结果表明,花药4℃低温预处理24h、48h较72h诱导效果好。NB培养基对愈伤组织的诱导效果比战培养基好。最佳愈伤组织诱导培养基组合为NB＋2,4-D0．5mg／L＋NAA0．3mg／L＋6-BA0．5mg／L＋KT3．0mg／L。通过不同蔗糖浓度对愈伤组织的诱导效果比较,表明低浓度的蔗糖有利于降低愈伤组织的褐化率,高浓度的蔗糖有利于单倍体愈伤组织的诱导。分化培养的最佳组合为MS＋NAA0．2mg／L＋6-BA3．0mg／L。诱导生根最好的培养基为1／2MS培养基,最适合蔗糖浓度为10g／L。     

Naïve averaged, naïve pooled, and population pharmacokinetics of orally administered marbofloxacin in juvenile harbor seals

OBJECTIVE: To determine the pharmacokinetics of marbofloxacin after oral administration in juvenile harbor seals (Phoca vitulina) at a dose of 5 mg/kg (2.3 mg/lb) and to compare pharmacokinetic variables after pharmacokinetic analysis by na?ve averaged, na?ve pooled, and nonlinear mixed-effects modeling. DESIGN: Original study. Animals-33 male and 22 female juvenile seals being treated for various conditions. PROCEDURES: Blood collection was limited to < or = 3 samples/seal. Plasma marbofloxacin concentrations were measured via high-pressure liquid chromatography with UV detection. RESULTS: Mean +/- SE dose of marbofloxacin administered was 5.3 +/- 0.1 mg/kg (2.4 +/- 0.05 mg/lb). The terminal half-life, volume of distribution (per bioavailability), and clearance (per bioavailability) were approximately 5 hours, approximately 1.4 L/kg, and approximately 3 mL/min/kg, respectively (values varied slightly with the method of calculation). Maximum plasma concentration and area under the plasma-time concentration curve were approximately 3 microg/mL and 30 h x microg/mL, respectively. Na?ve averaged and na?ve pooled analysis appeared to yield a better fit to the population, but nonlinear mixed-effects modeling yielded a better fit for individual seals. CONCLUSIONS AND CLINICAL RELEVANCE: Values of pharmacokinetic variables were similar regardless of the analytic method used. Pharmacokinetic variability can be assessed with nonlinear mixed-effects modeling, but not with na?ve averaged or na?ve pooled analysis. Visual observation by experienced trainers revealed no adverse effects in treated seals. Plasma concentrations attained with a dosage of 5 mg/kg every 24 hours would be expected to be efficacious for treatment of infections caused by susceptible bacteria (excluding Pseudomonas aeruginosa).     

Larvicidal activity of two Algerian Verbenaceae essential oils against Culex pipiens

The purpose of this study was to evaluate the bioactivity of essential oils extracted from the leaves of Verbena officinalis and Lantana camara L. for the control of Culex pipiens. Triplicate bioassays were performed with fourth larval instars of C. pipiens (n=25 per replicate) with solutions at 1, 5, 10, 50, 100 and 500 μL/L of V. officinalis and L. camara L. extracts. Cumulative mortalities were determined 3, 6, 12 and 24h after treatment. Results showed cumulative mortalities, at three (3) hours to be 30.0 ± 2.9% and 14.8 ± 1.5% and achieve 43.3 ± 1.9% and 44.4 ± 3.1% after 24h exposure time, at 100mg/L of essential oil from L. camara and V. officinalis, respectively.     

Cryptobia iubilans infection in juvenile discus

Four commercial producers of discus (Symphysodon aequifasciatus) were found to have fish infested with the flagellate Cryptobia iubilans. Affected fish had granulomatous gastritis, and many also had granulomatous disease of other organs. The parasite had to be differentiated from the related flagellates Spironucleus spp, which induce different lesions. Transmission electron microscopy was found to be useful in detecting and identifying the parasite. Morbidity and mortality rates in the various fish populations appeared to be linked to a number of variables, including water quality, presence of other parasites and bacteria, diet, species, size, and age of the fish, and optimization of husbandry appeared to be important in alleviating the severity of disease. Metronidazole was not effective for treatment of C iubilans, but bath treatments with dimetridazole (80 mg/L for 24 hours, repeated daily for 3 days) or 2-amino-5-nitrothiazol (10 mg/L for 24 hours, repeated daily for 3 days) may be useful in decreasing the prevalence of infestation.     

Safety of Strontium Chloride as a Skeletal Marking Agent for Pacific Salmon

Abstract

The purpose of this study was to evaluate the biological effects associated with administering strontium chloride as a marking agent to age-0 Chinook Salmon Oncorhynchus tshawytscha fry. Fish were held in a 0× (0 mg/L), 1× (3,000 mg/L; current standard dosage), 3× (9,000 mg/L), or 5× (15,000 mg/L) solution of strontium chloride for 72 h (three times the standard duration of 24 h). The mortality among fish in the 5× strontium chloride exposure group was significantly higher than that observed in the other groups. A dose-related effect on general fish behavior and on feeding behavior was observed. Fish in all test tanks appeared to feed to satiation, except for fish in the 5× tanks during days 2 and 3. Fish in all other test tanks behaved normally. No dose-related effect on fish growth was detected. Histopathological evaluations showed that fish in the 5× exposure group had a significantly higher number of gill lesions than the 0× group. Our mortality, behavioral, and histological assessments suggested that juvenile Chinook Salmon could be safely immersed for three consecutive days in a 9,000-mg/L solution of strontium chloride. This finding potentially expands the present 1,000–3,000-mg/L dosage and 24-h holding period that can be used to mark juvenile fish with strontium chloride solutions. The research also provides necessary target animal safety data for U.S. Food and Drug Administration approval of strontium chloride as an alternative marking method that is suitable for fish with a short holding time.

Received February 19, 2017; accepted July 16, 2017 Published online September 22, 2017