提高卤虫产卵率和产卵量的试验研究

依据江苏盐田自然条件，采取人为措施提高卤虫产卵量和产卵率，做了一些室内试验和研究，为其推广应用提供试验依据。     

提高卤虫产卵率的试验研究

本文通过对提高卤虫产卵率的定性,定量试验,论述了卤水PH值、天气变化、季节转换对卤虫产卵的影响。     

东亚小花蝽产卵基质适合性研究

【背景和目的】东亚小花蝽（Oriussauteri）是一种具有应用潜力的捕食性天敌。筛选适宜东亚小花蝽人工规模化饲养的产卵基质。【方法】选取芸豆荚（Phaseolus vulgaris）、龙豆荚（Psophocarpus tetragonolobus (Linn.) DC.）和长豇豆荚（Vigna unguiculata subsp. sesquipedalis (L.) Verdc.）为产卵基质,比较东亚小花蝽在3种基质上的产卵量、孵化率及F1代性比,及评价卵在10℃条件的耐藏性。【结果】（1）东亚小花蝽在芸豆荚上的单雌平均产卵量和孵化率最高,分别为92.52粒和90.47%;龙豆荚为89.90粒和90.16%,两者差异不显著,但显著高于长豇豆荚的78.70粒和80.49%;(2)10℃冷藏,芸豆荚和龙豆荚上的卵孵化率差异不显著,但显著高于长豇豆荚上的卵孵化率（P<0.05）;(3)冷藏20d时,芸豆荚上卵孵化率为70.22%,龙豆荚为67.77%,长豇豆荚为31.58%。【结论】芸豆荚和龙豆荚可作为东亚小花蝽规模化饲养的产卵基质。     

两种虫蛹冷藏存活率及其作为配对期食物对蠋蝽产卵的影响

针对蠋蝽规模化繁育中成虫配对期食物的优化,研究了黏虫蛹和黄粉虫蛹低温保藏后的存活率及其作为配对期食物对蠋蝽产卵的影响。结果表明,黄粉虫蛹和黏虫蛹在6℃保藏30 d后的存活率分别为89.33%、22.67%;蠋蝽配对期以冷藏黄粉虫蛹为食物,其总产卵量、单次平均产卵量、孵化率均显著高于以冷藏黏虫蛹为食物;蠋蝽对冷藏黄粉虫蛹的捕食偏好高于冷藏黏虫蛹。以冷藏的黄粉虫蛹作为配对期食物对提高蠋蝽人工扩繁效率具有重要意义。     

产卵前后长江刀鲚肉中营养成分差异

对比研究了产卵前后长江刀鲚肉的营养价值以及在产卵过程中营养成分的代谢。结果表明产卵后长江刀鲚肉粗脂肪含量显著降低(p0.05)。两个时期的鱼肉均含有丰富的脂肪酸,尤其是单不饱和脂肪酸。产卵后大部分不饱和脂肪酸含量显著下降,而饱和脂肪酸所占比例显著上升。不饱和脂肪酸中C17∶1,C20∶4和C18∶2n6c含量下降最多,分别为97.72%,96.67%和88.77%。而C14∶1与C20∶3n6的含量发生显著性上升。产卵前后刀鲚肉中n-3/n-6为7.71、9.32,P/S为0.40、0.60。产卵后氨基酸总量显著高于产卵前(p0.05),分别为60.00 g/100 g和43.17 g/100 g(干重)。其中半必需氨基酸His含量升高最多,增长了85.12%。产卵前后刀鲚肉AAS值均大于100,EAAI值为157、161。产卵前后K的积累和Na的消减与刀鲚产卵时向淡水洄游的生殖洄游习性相吻合,产卵后Cu和Mn含量显著降低,用于产卵过程中维持卵巢发育。两个时期的刀鲚肉中均含有丰富的Ca。     

简易的产卵鸡舍

用廉价的材料或将空房或建筑物,改造成有用的产卵鸡舍(见图1),可以节省大量投资。简易鸡舍可用木料或砖瓦建造。用木料建成仓库式鸡舍,简易省工,监不需要严     

雅脊金小蜂长翅型雌蜂繁殖和搜索能力研究

本文就雅脊金小蜂 Theocolax elegans(Westwood,1874)的繁殖能力和对米象幼虫的搜索能力进行了研究。结果发现,温度和繁殖方式都会影响雅脊金小蜂的产卵能力,包括产卵期、单雌产卵量和子代性比;在小麦粒中,雅脊金小蜂的垂直搜索能力可达30cm 以下。     

虫害诱导烟草抗性对斜纹夜蛾生长和产卵选择的影响

[目的]探究不同品种烟草的虫害诱导抗性对斜纹夜蛾生长和产卵选择的影响.[方法]选取了野生种的八旦野生烟、地方品种的梁桥晒烟和选育品种的湘烟5号3个烟草品种,测试斜纹夜蛾幼虫取食不同品种烟草的对照组和虫害处理组后的生活史参数;观察斜纹夜蛾成虫对不同品种烟草的产卵选择偏好性.[结果]斜纹夜蛾幼虫取食诱导的烟草,对后续再取食...     

枸杞对秀丽隐杆线虫寿命和产卵的影响及其抗氧化作用

目的：研究枸杞对秀丽隐杆线虫（以下简称线虫）寿命和产卵的影响,探讨其抗氧化的相关机制。方法：采用铁离子还原/抗氧化能力法体外检测,比较了宁夏中宁、青海、甘肃3 个产地的枸杞抗氧化能力的差异。采用活性氧（reactive oxygen species,ROS）-敏感染料2’,7’-二氯-二氢荧光素乙酰乙酸盐检测枸杞对线虫体内ROS的影响,同时采用实时荧光定量聚合酶链式反应检测枸杞对线虫体内相关抗氧化酶水平的影响。将同步化后L4时期的线虫分别放置于对照或添加枸杞提取物的NGM平板上培养,检测枸杞对线虫产卵和寿命的影响。采用两种转基因（Pmyo3::HyPer和roGFP2::Orp1）线虫为模型检测枸杞提取物对线虫胞质中H2O2的清除能力,采用荧光染料MitoSox Red检测枸杞提取物对线虫细胞线粒体中超氧阴离子自由基的清除能力。结果：3 个产地的枸杞均具有很强的体外抗氧化能力,它们之间没有明显差异。枸杞可以降低线虫体内ROS水平以及提高抗氧化酶的水平。枸杞对线虫寿命和产卵能力并没有明显的影响。枸杞可以清除线粒体超氧阴离子自由基,但不影响胞质H2O2水平。结论：枸杞在体外与体内均有一定的抗氧化能力,其主要通过清除线粒体超氧阴离子自由基在体内发挥抗氧化作用,枸杞对线虫的寿命和产卵数没有明显影响。     

柞蚕饰腹寄蝇的防治方法

柞蚕饰腹寄蝇俗称蚕寄蝇、蛆蛟、蝇蛆．是辽宁省主要柞蚕产区危害最为严重的一种柞蚕寄生虫病。它在每年春柞蚕上发生一次。以凤城、宽甸、岫岩、东港为重。近几年已扩展到庄河、瓦房店、西丰等地。柞蚕饰腹寄蝇5月下旬到6月下旬产卵．6月上旬为产卵寄生盛期。     

Post-mortem changes of muscle from fresh water prawn (Macrobrachium rosenbergii) as influenced by spawning stages

Post-mortem changes of the muscle from pre- and post-spawned fresh water prawn (Macrobrachium rosenbergii) were comparatively monitored during 7 days of iced storage. During the storage, the muscle of pre-spawned prawn had a greater value of trichloroacetic acid (TCA) soluble peptide, heat soluble collagen and pepsin-soluble collagen (PSC) contents than did post-spawned counterpart. Those components in the muscle of both prawns increased markedly after 3 days of storage (p < 0.05). Conversely, insoluble collagen (ISC) content, shear force value and texture liking of both prawns decreased (p < 0.05), indicating the softening of muscle. No changes in protein patterns were observed, except the decreased band intensity of 66 kDa protein in water soluble fraction of both prawns was found after 3 days of storage. T_max and enthalpy of PSC from both prawns decreased during the first 4 days of storage (p < 0.05), suggesting the degradation or denaturation of collagen in the muscle. Light microscopic study showed the lowering of intercellular connection of raw meat and higher gaping in cooked meat when the samples were stored for a longer time. Therefore, post-mortem characteristics of prawn muscle was affected by storage time and spawning stages.     

Changes in ω-3 Polyunsaturated Fatty Acids in the Chum Salmon Muscle During Spawning Migration and Extrusion Cooking

The effects of spawning migration and extrusion cooking on o-3 polyunsaturated fatty acids (PUFAs) in chum salmon muscle were studied. Total lipid content in the muscle of the fish during spawning migration was lower than that during feeding migration. However, the content increased to double those in the raw materials by pretreatment of extrusion cooking. Lipids of muscle and outer layer during spawning migration contained higher percentages of docosahexaenoic acid (22:6) than those during feeding migration. Moreover, PUFAs were not lost by extrusion cooking and its pretreatment. These results suggest that production of foods containing a rich amount of W-3 PUFAs is possible by extrusion cooking of the muscle of chum salmon during spawning migration.     

Assessment of quality of cod roes and relationship between quality and maturity stage

Cod roe landings are subject to great variability regarding their quality and subsequent price for the food industry. A scheme was developed for the classification of cod roe into four quality grades (A, B, C and D) based on appearance and texture attributes as described by cod roe traders. Evaluation of the maturity stage of 80 commercial cod ovaries through the frequency distribution of oocyte diameter and the percentage presence of empty follicular sacks revealed that cod ovaries with commercial value are at stage 4 (ripe or vitellogenic), stage 5 (spawning) and stage 6 (spent) of development. The designated maturity stages were found to be closely related to the described quality grades. This relationship implied that vitellogenic ovaries (stages 4a, 4b and 4c) were of A quality, early spawning ovaries (stage 5a) were most often classed as B quality, advanced and late spawning ovaries (stage 5b and 5c) were of C quality, whilst spent ovaries (stage 6) were of the lowest quality grade (D). Several physicochemical characteristics recorded (eg pH, membrane features) were also found to be related to the quality and the maturity stage of the ovaries. There is a significant relationship between roe quality and moisture content, with roes of higher quality having a lower moisture content. © 1999 Society of Chemical Industry     

Lipid reserve dynamics and magnification of persistent organic pollutants in spawning sockeye salmon (Oncorhynchus nerka) from the Fraser River, British Columbia

Pacific sockeye salmon (Oncorhynchus nerka) can travel several hundred kilometers to reach native spawning grounds and fulfill semelparous reproduction. The dramatic changes in lipid reserves during upstream migration can greatly affect internal toxicokinetics of persistent organic pollutants (POPs) such as PCBs, PCDDs, and PCDFs. We measured lipid content changes and contaminant concentrations in tissues (liver, muscle, roe/gonads) and biomarker responses (ethoxyresorufin O-deethylase or EROD activity and CYP1A levels) in two Pacific sockeye salmon stocks sampled at several locations along their spawning migration in the Fraser River, British Columbia. Muscle lipid contents declined significantly with increasing upstream migration distance and corresponded to elevated lipid normalized concentrations of PCBs and PCDD/Fs in spawning sockeye. Post-migration magnification factors (MFs) in spawning sockeye ranged between 3 and 12 and were comparable to model-predicted MFs. sigmaPCBs(150-500 ng x g(-1) lipid), sigmaPCDD/Fs (1-1000 pg x g(-1) lipid) and 2,3,7,8-TCDD toxic equivalent or TEQ levels (0.1-15 pg x g(-1) lipid) in spawning sockeye were relatively low and did not affect hepatic EROD activity/CYP1A induction. Despite a 3-fold magnification, TEQ levels in eggs of spawning Fraser River sockeye did not exceed 0.3 pg x g(-1) wet wt, a threshold level associated with 30% egg mortality in salmonids. PCBs in Fraser River sockeye are comparable to previous levels in Pacific sockeye. In contrast to Pacific sockeye from more remote coastal locations, PCDDs and PCDFs in Fraser River sockeye were generally minor components (<25%) of TEQ levels, compared to dioxin like PCB contributions (>75%). The data suggest that (i) the Fraser River is not a major contamination source of PCBs or PCDD/Fs and (ii) marine contaminant distribution, food-chain dynamics, and ocean-migration pathway are likely important factors controlling levels and patterns of POPs in returning Pacific sockeye. We estimate an annual chemical flux entering the Fraser River of up to 150 g for sigmaPCBs and 40 mg for sigmaPCDD/ Fs via returning sockeye. The results indicate that historical concentrations of PCBs and PCDD/Fs remain a potential threat to organism and ecosystem health on the west coast of Canada.     

Fate of chlorinated fatty acids in migrating sockeye salmon and their transfer to arctic grayling

To investigate whether biotransport constitutes an entry route into pristine ecosystems for nonpersistent, nonvolatile xenobiotic compounds, extractable organically bound halogen in sockeye salmon (Oncorhynchus nerka) from Alaska was determined before and after spawning migration. The major organohalogen compounds in the salmon were halogenated fatty acids, predominantly chlorinated species that accounted for up to 35% of the extractable, organically bound chlorine (EOCl) in the fish tissues. The amount of chlorinated fatty acids in the salmon muscle decreased as a result of spawning migration. The decrease was correlated with that of triacylglycerols in the salmon muscle, indicating the chlorinated fatty acids to be mobilized and metabolized to approximately the same extent as the other fatty acids. Chlorinated fatty acids were also transferred to the maturing roe in a manner similar to that of the unchlorinated fatty acids. Lipids of the Arctic grayling (Thymallus arcticus), a fish resident to the spawning lake of the salmon, contained higher concentrations of chlorinated fatty acids than grayling in a lake without migratory salmon. This may reflect a food-chain transfer of the chlorinated fatty acids originating from the salmon, demonstrating a long-range transport route for this type of pollutants to pristine areas.     

Dairy wastewater, aquaculture, and spawning fish as sources of steroid hormones in the aquatic environment

A suite of androgens, estrogens, and progestins were measured in samples from dairy farms, aquaculture facilities, and surface waters with actively spawning fish using gas chromatography-tandem mass spectrometry (GC/MS/ MS) to assess the potential importance of these sources of steroid hormones to surface waters. In a dairywaste lagoon, the endogenous estrogens 17beta-estradiol and estrone and the androgens testosterone and androstenedione were detected at concentrations as high as 650 ng/L. Samples from nearby groundwater monitoring wells demonstrated removal of steroid hormones in the subsurface. Samples from nearby surface waters and tile drains likely impacted by animal wastes demonstrated the sporadic presence of the steroids 17beta-estradiol, estrone, testosterone, and medroxyprogesterone, usually at concentrations near or below 1 ng/L. The endogenous steroids estrone,testosterone, and androstenedione were detected in the raceways and effluents of three fish hatcheries at concentrations near 1 ng/L. Similar concentrations were detected in a river containing spawning adult Chinook salmon. These results indicate that dairy wastewater, aquaculture effluents, and even spawning fish can lead to detectable concentrations of steroid hormones in surface waters and that the concentrations of these compounds exhibit considerable temporal and spatial variation.     

American dippers indicate contaminant biotransport by Pacific salmon

Migrating salmon can increase productivity in Pacific Northwestern streams and lakes through the deposition of nutrients from their decomposing carcasses after spawning. Several studies also report simultaneous biotransport of persistent organic pollutants that have contaminated lake food webs, although no similar effect has been shown conclusively in rivers. We tested the prediction that salmon enhance contaminants in river food webs using the American dipper (Cinclus mexicanus), an aquatic songbird and a recognized indicator of stream quality. Over 3 years, we analyzed 29 dipper eggs and aquatic invertebrate samples from 14 different rivers in 10 catchments in southern British Columbia, Canada to assess whether variations in autumn spawning density of Pacific salmon were reflected in dipper egg contamination or stable carbon and nitrogen isotopes. δ(13)C isotope signatures, but not δ(15)N, in aquatic invertebrates and dipper eggs increased among catchments in proportion to the average density of spawning salmon. Concentrations of brominated flame retardants (PBDEs), dichlorodiphenyltrichloroethane metabolites (DDTs), and chlordane compounds were related in part to the δ(13)C measure of salmon density, but mercury, chlorobenzenes, and polychlorinated biphenyls (PCBs) were explained better by dipper trophic level. We conclude that spawning Pacific salmon result in the increased availability of salmon fry as dipper prey and salmon are a significant source of PBDEs, DDTs, and chlordanes to river ecosystems. However, contrary to lake studies, postspawn concentrations of legacy PCBs in river birds, even in salmon-rich rivers, were not significantly higher than would be expected from atmospheric deposition alone. We recommend using δ(13)C isotopes to trace salmon-derived lipids which may persist over winter particularly in rivers, and are potentially a better reflection of lipophilic contaminant transfer.     

Storage life of chilled Patagonian hake (Merluccius hubbsi)

The storage life of iced Patagonian hake ( Merluccius hubbsi ) was studied. Seasonal changes were investigated by means of organoleptic assessments (raw and cooked), total volatile bases (TVB) and pH.
During summer-time (December to March) the keeping time, from the edibility point of view, for round hake in ice is not more than 9 to 10 days; in the remaining months the storage life under the same conditions is up to 14 to 15 days.
The difference could be due to the biological condition of hake during and after the spawning time (end of spring-beginning of summer), the shallow and temperate waters of the fishing grounds in summer, and the heavy feeding after spawning.
Comparison trials between gutted and ungutted hake in ice, and between ungutted hake in ice and in chilled sea water (CSW) were also performed.
The duration of rigor mortis of whole hake stored in ice, and the feasibility of quality assessment by an electronic device were also studied.     

Sensory properties of marinated herring (Clupea harengus) processed from raw material from commercial landings

Sensory properties of marinated herring processed from raw material from Danish commercial catches were described and related to fishing season and biological, chemical and functional properties. Herring was caught on five cruises and stored on board in tanks or ice. The sensory profile of marinated herring from the North Sea was influenced by season, and changes coincided with the cycle of feeding and spawning. During the spawning period the texture was soft and the muscle more susceptible to lipid oxidation. The texture became firmer and the fatty mouth feel stronger during the feeding period, and the odour and flavour characteristics less rancid. These effects were explained by the chemical composition and biological parameters. The sensory profile was influenced by herring size and age, but not by sex or gonad maturity; the storage method also had an effect. Herring from the Kattegat stored in ice smelled and tasted more of fresh herring and were juicier than herring from the North Sea stored in tanks. Copyright © 2004 Society of Chemical Industry