气相色谱法测定禽蛋中有机氯农药和多氯联苯残留量

建立了同时测定禽蛋中14种有机氯农药(OCPs)和7种多氯联苯(PCBs)的气相色谱法。样品用乙腈超声提取,浓硫酸净化,气相色谱法测定,外标法定量。21种待测化合物在5～200μg/L时线性关系良好,方法定量限为0.3～0.7μg/kg,在5、20、100μg/kg三个加标水平下,鸡蛋空白样品的平均加标回收率为75.1%～103.8%,相对标准偏差为1.41%～6.64%。本法简便、快速、准确、成本低廉,适用于禽蛋中多种有机氯农药和多氯联苯的快速筛查。     

Heterotrophic Aurantiochytrium sp. supplementation to layer diets sustainably increases the omega-3 concentration of eggs

ABSTRACT

1. The consumption of adequate amounts of the long-chain polyunsaturated omega-3 fatty acids (n-3 LC-PUFA) has been associated with beneficial effects on human health. Eggs are commonly consumed worldwide, and their omega-3 content can be easily altered by changing the diets of laying hens and so represent an important target for enrichment.

2. In this study, the effect of supplementing laying hens with DHA-rich, Aurantiochytrium limacinum at three different inclusion levels was investigated over a 24-week period.

3. Significant increases in egg DHA concentrations were observed after four weeks and were maintained for the duration of the 24-week study. The supplemented eggs in the current study had a DHA content of 82, 101, and 129 mg/yolk when supplemented with 0.25%, 0.5% and 1% treatments, respectively, which meets the EU criteria to be considered ‘high in omega-3?.

4. Using the sustainably grown protist Aurantiochytrium limacinum to supplement layer diets increased the egg DHA concentration and decreased the n-6/n-3 ratio, improving the nutritional value of the eggs for human consumers.     

刺鲃鱼卵营养成分分析及评价

为了对刺鲃(Spinibarbus caldwelli)鱼卵的营养品质进行评价,本试验采用常规方法对刺鲃鱼卵的一般营养成分含量、氨基酸组成、脂肪酸组成和微量元素含量进行了测定。结果表明:刺鲃鱼卵(鲜样)中粗蛋白质含量为27.66%、粗脂肪含量为3.18%、水分含量为64.26%、粗灰分含量为3.09%。刺鲃鱼卵共检测出17种氨基酸,其中必需氨基酸(EAA)7种,非必需氨基酸(NEAA)10种,总氨基酸(TAA)含量为23.21%,EAA含量为9.28%,NEAA含量为13.93%;EAA构成比例符合FAO/W HO标准,分别以氨基酸评分(AAS)和化学评分(CS)进行评价,其第一限制性氨基酸均为蛋氨酸+半胱氨酸,第二限制性氨基酸均为苯丙氨酸+酪氨酸。必需氨基酸指数(EAAI)为59.26%。刺鲃鱼卵共检测出11种脂肪酸,其中3种饱和脂肪酸(SFA)、3种单不饱和脂肪酸(MUFA)、5种多不饱和脂肪(PUFA),分别占脂肪酸总量的22.68%、48.40%、28.93%;C20∶5n-3(EPA)+C22∶6n-3(DHA)占脂肪酸总量的8.53%。刺鲃鱼卵中微量元素铜、锌、铁、锰、硒含量丰富,其中锌、铁含量分别高达90.986 5、31.386 3 mg/kg。由此得出,刺鲃鱼卵营养丰富,有较高的综合开发利用价值。     

枝角类适种探索和休眠卵的利用

实验表明多刺裸腹蚤是最易培养的淡水枝角类。适宜条件下接种后６ｄ可达５０００个／Ｌ的生一,人为改变饵 料及水温条件可获得大量休眠卵。休眠卵无休眠期,适宜条件下可卵化。孵化时数与水温的为Ｈ＝４７４．３２５９－２９．４５１５Ｔ＋０．４７８３Ｔ＾２。干燥低温保存休眠卵效果较好。１年后的孵化率可达６０％。     

Nonlocal wind-driven fjord–coast advection and its potential effect on plankton and fish recruitment

The Bergen Ocean Model (BOM), a three-dimensional physical coastal ocean model, was used for a numerical simulation experiment to investigate short-term effects of wind-generated coastal upwelling and downwelling on the dynamics of adjacent large outer and smaller inner fjords. The effect of the real alongshore wind regime on advection for an idealized fjord topography, resembling Masfjorden, western Norway, is used as an example. This modelling exercise is a supplement to, and its predictions support, the various hypotheses investigated in ecosystem simulation studies of the Masfjorden. The model predicts that coastal winds from the north cause upwelling and transport the upper water layer out from the fjords. Winds from the south cause downwelling and transport the upper water layer into the fjords. The transport is rapid and ≈50% of the upper water layer may be replaced within 1–2 days. Implications of these physical processes for the dispersal and retention of planktonic organisms and the early life stages of fish are discussed. If strong southerly winds occur frequently, this will transport planktonic organisms into the fjord and may increase the carrying capacity for planktivorous fish. In contrast, frequent strong northerly winds may reduce the abundance of planktonic organisms, including the early life stages of marine fish, and thus possibly reduce recruitment to fjord fish populations. Frequent shifts between southerly and northerly winds would cause an exchange of early life stages between neighbouring fjords and thus enhance genetic exchange.     

大鳞副泥鳅幼苗敌百虫毒性试验的研究

在大鳞副泥鳅人工繁殖过程中,发现剑水蚤特别容易在孵化箱内聚积,严重地影响了孵化效果.为了解决生产中出现的问题,进行了大鳞副泥鳅幼苗敌百虫毒性试验.选择敌百虫晶体原液(含量≥90%),试验设计一个空白组和五个浓度梯度试验组,每组放入幼苗30尾,经24 h和48 h的观察后,试验结果:大鳞副泥鳅苗种安全浓度为1.25 mg...     

真蛸人工繁殖及受精卵孵化技术研究初报

真蛸为福建省近年来新兴的海水养殖优良种类,具有较高的营养价值、商品价值和产业化养殖前景。本文报道了福建省水产研究所2008年-2011年真蛸人工繁殖及受精卵孵化结果：127头雌亲蛸经强化培育,共有77头产卵,获卵194×10^4粒,孵出143．4×10^4头浮游幼体。雌亲蛸获产率46．2％～86．7％,卵子受精率75．6％-91．8％,受精卵孵化率77．9％～95．0％。在20．0～22．5℃水温条件下,真蛸受精卵经21～36d开始孵出,孵出后4～6d为孵出高峰,每窝卵开始孵出至孵化结束维持10—16d。     

长江中游监利江段鱼卵及仔稚鱼时空分布

2010年5-7月对长江中游监利江段鱼卵和仔稚鱼的时空分布进行调查,共采集到鱼卵样品9494粒,仔稚鱼样品328422尾,分属8目15科43属51种.结果显示:5-7月鱼卵的平均密度为13.3 ind./100m3,最大密度值87.8 ind./100 m3,主要集中在5月;5-7月仔稚鱼平均密度为61.8 ind./...