997 resultados para 13368-008
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毛发是评估下丘脑-垂体-肾上腺轴(HPA轴)慢性活性变化很好的样品,毛发皮质醇的提取方法非常重要.为保证毛发皮质醇提取过程的可靠性,实验使用了液氮冷冻研磨:设计了空白对照组(磷酸缓冲液(PBS))(n=3)、原管组(n=10)和新管组(n=10),以检验缓冲液、离心管对提取的潜在干扰;对同一动物样品(n=16)两次独立提取的结果及毛发皮质醇浓度与受到的极端攻击量(血浆皮质醇浓度的间接指标)(n=16)进行了Pearson相关分析.结果表明:空白对照组测量结果为0pg/mg:新管浓度值与原管无显著性差异(F(1,19)=0.041,P=0.843,one-wayANOVA);两次独立提取结果高度正相关(r=0.893,P=0.000);皮质醇浓度与受到的极端攻击量中度正相关(r=0.591,P=0.008).因此,离心管、缓冲液对实验没有显著性干扰,溶液中皮质醇来源于毛发样品;提取操作流程可靠,所得数据可信.
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Platycephalus indicus is a large benthic fish that inhabits temperate and tropical coastal waters of the Indo-West Pacific and found on sand or mud bottom in vary shallow area of estuary and near shore to depth of 25m. This species is dominant species of platycephalidae family, in Khuzestan, Bushehr and Hormozgan provinces and mainly is captured by bottom trawl, gillnet and moshta in Hormozgan. This study was designed to evaluate population variation and differentiation of bartail flathead (Platycephalus indicus (Linnaeus, 1785))in the Iranian waters of Persian Gulf using the morphometric and meristic characters and by AFLP marker. . A total 180 fish specimens were collected by gill net from six station(khor mosa, bahrekan, shif, motaf, charak and bandar abbas) that was 30 individual related to every station in Iranian shores of Persian Gulf . 28 morphometric factors and 11meristic specialties were measured and morphometric factors was standardized with Beacham formula. Univariate analysis of variance (One-way ANOVA) revealed significant differences with varying degrees between the means for 21 standardized morphometric measurements and 6 meristic counts that showed high significant differences between the six stations sampling. Discriminate function analysis (DFA) or the overall random assignment of individuals into their original groups was for morphometric and meristic characters was 47.9% and 53.9% respectively. The data were subjected to a principle component analysis (PCA) which grouped in eight and four factors for morphometric and meristic charactersrespectively.. Genetic diversity of six populations of bartail flathead (Platycephalus indicus) was investigated using amplified fragment length polymorphism (AFLP). A total of 118 reproducible bands amplified with ten AFLP primer combinations were obtained from 42 fishes that were collected from six different locations in the northern of Persian Gulf. The percentage of polymorphic bands was 57.06%. Average of Nei’s genetic diversity was 0.200±0.008, and Average of Shannon’s index was 0.300±0.011. The results of AMOVA analysis indicated that 66% of the genetic variation contained within populations and 34% occurred among populations and gene flow was 0.6454.The estimated level of population differentiation asmeasured by average Fst value across all loci was 0.327. Plotting discriminant functions 1 and 2 and UPGMA dendrograms based on Euclidian distance and genetic distance also showed at least five separate populations of bartail flathead in the northern Persian Gulf.
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The toxicities of four insecticides and a herbicide to Tilapia macrochir were tested in the laboratory. The 24 hour LC50's were estimated as follows: Endrin 20% ,0.008 ppm; Lindane 5% granules, 4.6 ppmm; Synexa 50 (HCH) 50%), 5.6 ppm; Synex 25 (HCH 25%), 14.8 ppm; TOK herbicide (Nitrofen), 100% survival for 24 hours at 100 ppm. These estimates agree with results obtained by other workers elsewhere in the world. The laboratory determination of toxicity is important in estimating the direct effects of poisonous substances on fish, but other indirect effects may result from their use. These should be investigated in the field.
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浮桥河水库浮游植物水柱日生产量变幅为0.34-4.99 g/(m~2-d),最低值出现在下游冬季,最高值出现在中游秋季,年平均值2.75 g/(m~2·d).季节变化:秋季>夏季>春季>冬季,与浮游植物叶绿素a含量和生物量的季节变化一致;水平分布:中游略高于上游,下游最低,与浮游植物叶绿素a含量的水平分布完全一致.表层日生产量占水柱日生产量53.81%.与1980年同期相比,浮游植物初级生产力增加了1.2倍.分析表明,磷含量增加是浮游植物初级生产力提高的关键因子.应用能量收支法估算浮桥河水库鲢鳙渔产潜力为
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国家“九五”科技攻关项目(96-008-02-03); 中国科学院重大项目(KZ951-A1-102-01;KZ951-B1-104); 国家自然科学基金(39625006;39670573;39970584); 国家重点实验室基金(39823003); 广东海大畜牧水产有限公司的资助
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采用不同方法测定了鱼粉、豆饼、鱼油、豆油的脂肪含量。结果表明,不同测定方法测定的值显著不同,测定鱼粉和豆饼时,以氯仿-甲醇为溶剂抽提测得的脂肪含量高。测定鱼油和豆油时,氯仿-甲醇冷抽提测定的值较高。
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国家“九五”攻关项目96-008-02-3;国家自然科学基金39670575、39625006;中国科学院资环局重大项目KZ951-A1-102-01;淡水生态
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作者研究了不同水系河蟹在长江中游湖泊养成后于秋冬季捕捞期间成蟹日产量动态特点。结果表明,盘锦苗种、天津苗种、长江苗种日产量高峰时间分别为9月上旬、9月中旬、10月上旬,瓯江苗种的高峰时间最早在10月19日,最晚出现在11月17日。苗种来源水系纬度(Y)与成蟹日产量高峰出现时间(X:天,8月28日为第一天)呈线性相关:Y=43.182-0.232X(n=13,r=-0.96)。
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本实验结果表明,野生鳜和乌鳢的干物质含量、蛋白质含量、脂肪含量和能值均随体重的增加而显著增加(P<0.05),野生鳜灰分含量亦随体重的增加而显著增加(P<0.05),但野生乌鳢灰分含量与体重关系的回归方程则不显著(P>0.05);实验鳜和乌鳢干物质含量、脂肪含量和能值均随摄食水平的增加而显著增加(P>0.05),实验鳜蛋白质含量和灰分含量与摄食水平关系的回归方程不显著(P<0.05),实验乌鳢蛋白质含量随摄食水平的增加而显著增加(P>0.05),灰分含量随摄食水平的增加而显著减小(P>0.05)。尽管不同
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国家自然科学基金96-008-02-03
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1995年10月至1996年11月运用标志回捕法对保安湖1#试验围拦中麦穗鱼的种群数量作了11次估算,并对种群的动态特征进行了分析。 周年的种群数量变动于0.40-2.45ind·m-2,在5月份最高。不同世代的强度存在较大的差异,1996年世代最强,1996年11月为21,631ind,与同期的1995世代(14,431ind)相比增加了49.9%,死亡率在夏季较高。1995世代周年死亡率为71.7%,1996年11月的数量为4,084ind,与生活史中同期的1994世代(1,515ind)相比,增加了
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研究了人工海水、天然半咸水以及生理盐水对6种我国常用抗菌药物(环丙沙星、四环素、土霉素、氯霉 素、磺胺以及呋喃唑酮)体外抗两种鱼类病原细菌(Aeromonas hydrophila和Vibrio fluvialis)活性的影响。结果表明:海水对几乎所有受试药物的抗菌活性均呈抑制作用,其中对土霉素的影响最为显著;半咸水可使土霉素、 四环素及磺胺药的抗菌活性下降;生理盐水对不同药物或不同细菌的作用不一致;呋喃唑酮的抗菌活性不受 3种水质的影响。此外,喹诺酮与二价阳离子的螯合产物可能并不稳定,当用无二价阳离子水
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通过消除对沉水植物生长有破坏作用的草食性鱼类和杂食性鱼类,在低水位的早春选择无风浪的天气移栽水草,于 1994年在保安湖一个面积为 3 .3hm~2网栏湖汊成功地恢复了绝迹 8个月的水草群落,秋季水草覆盖率达 50%,同时研究了在无鱼类摄食破坏的条件下苦草和黄丝草的生长动态.于1994-1995年在保安湖另一个面积为133.3hm~2土栏湖汊(即肖四海)恢复了水草群落,1995年秋季水草覆盖率达70%,由于水草群落的恢复,肖四海结束了施肥投草主养四大家鱼的养殖方式,而采用了以河蟹和鳜鱼为增养殖对象的优质高
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本文对河蟹幼蟹蜕壳过程及蜕壳后的特征进行了比较详细的观察,并初步探讨了蜕壳与光照、温度及生境的关系对于0.5-2g的幼蟹,蜕壳期大约需要3-6h,软壳期需要2h,薄壳期需要15h.幼蟹特别喜欢选择有草的生境作为蜕壳地点,也喜欢在池塘浅水区蜕壳,但是在2m以内水深对蜕壳成功率没有影响.蜕壳存在明显的昼夜节律,白天蜕壳的数量显著高干夜间(F(1.30)= 13. 4, P= 0. 0009),蜕壳高峰发生在上午(07: 00- 11: 00),低谷一般发生在夜间(23: 00- 03:00).协方差分析(昼夜
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在保安湖的两个湖区(扁担塘和龙王头)和牛山湖的一个围拦湖汊中对放流河蟹的生长指标逐月采样研究,结果表明,三个水体虽同属长江中下游典型草型湖泊,但河蟹在生长末期规格(壳宽、体重)上表现出一定差异。扁担塘(瓯江种)、龙王头(瓯江种+长江种)成蟹规格较一致,群体壳宽分别为6.70±0.59、6.73±0.56cm,体重分别为155.1±36.0g、158.0±36.1g。而牛山湖湖议成蟹壳宽为5.63±0.43cm,体重为103.2±26.3g,与前两者相比,差异显著。原因可能主要是后者放养时间太晚(1997年