Op—Ca保鲜剂对鲅鱼的保鲜效果

本文报告了常温下Op-Ca保鲜剂对鲅鱼（scomberomorus niphous)的保鲜效果。用0．05％的Op-Ca保鲜剂溶液浸泡鲅鱼30min后在常温（23℃）下贮藏，通过感官评价和细菌总数、T－VBN值等鲜度指标的测定，发现该保鲜剂对常温下的鲅鱼有较好的保鲜效果，能够延长常温下鲅鱼的保鲜期2天以上。     

运输时间及水温对南美白对虾苗成活率的影响

在不同的温度(18℃、20℃、22℃、24℃、26℃)和时间(8h、14h、20h、26h、32h)条件下对南美白对虾苗进行运输。试验结果表明：运输时间和运输水温及两者的交互作用对南美白对虾苗成活率均有显著影响。多重比较结果显示运输时间在20h以内，不同时间梯度对南美白对虾苗的运输成活率的影响无显著差异，成活率均在90℃左右，随着运输时间的延长，虾苗成活率明显降低，且不同时间梯度间差异显著；运输用海水的温度控制在22～24℃时，虾苗具有较高的成活率，随着水温的升高或降低，成活率均明显降低，且不同温度梯度间差异显著。在本试验条件下，不同运输时间和运输水温对南美白对虾苗运输后暂养的成活率和生长无显著影响。     

冻结贮藏条件下鲈鱼鲜度和质构变化

研究冻结贮藏条件下鲈鱼组织构造、质地剖面分析（TPA）及流变学特征参数（弹性模量E，应力松弛时间τ，粘性模量η，破断强度gf）的变化，同时结合鲜度指标（细菌总数，K值，TVB—N，pH值）和感官特性判断其品质变化特征。结果表明：随着冻结时间的延长，鲈样品细菌总数下降，K值和TVB—N上升；组织构造呈现纤维间空隙增大、方向性增强、断裂崩解的趋势；弹性模量呈上升趋势，破断强度、硬度、弹性、粘聚性、咀嚼性均呈下降趋势，应力松弛时间、粘性模量的变化则不显著。与冷藏样品相比，冻结样品具有鲜度高、货架期长的特点。     

南美白对虾健康养殖中pH值的影响与调控

南美白对虾具有生长快、抗病力强、适应范围广的特点，这是近年来南美白对虾养殖规模迅速扩大的基本原因。但随着养殖密度与产量的提高以及养殖年限的延长，南美白对虾疾病流行日趋严重。造成南美白对虾疾病的原因很多，水质恶化是其中重要的因素，而pH值又是影响水质的关键因素之一。     

水温与pH值对南美白对虾白斑病发病的影响

实验通过在不同温度和pH值下,对南美白对虾发病情况进行了研究.结果表明温度越高,虾的发病时间越早,发病率越高;pH值在7.8～8.2时发病时间最迟,发病率最低.通过使温度降低和使pH值在7.8～8.2之间,可以延迟对虾的发病时间,降低发病率.     

淡水小棚养殖南美白对虾试验

<正>南美白对虾养殖过程中池水的温度、盐度、pH值、溶解氧以及营养盐的含量等各项指标对养殖产量的提高有极大影响。铵盐与亚硝酸盐对南美白对虾均有致毒作用。因此,了解并提高养殖过程中虾池水质是非常必要的。该文为2016年在营口天时水产公司进行的淡水小棚养殖南美白对虾试验结果,并对南美白对虾淡水养殖过程中对虾池的水质进     

0 ℃冷藏条件下鲢阻抗特性与鲜度变化的相关性

为了更好地了解0 ℃冷藏条件下鲢（Hypophthalmichthys molitrix）鱼体的阻抗特性与鲜度的变化规律及相关性,建立鱼体鲜度快速检测方法,分别测定了鲢鱼片的品质指标[菌落总数、肌苷和次黄嘌呤浓度总和/ATP关联物浓度总和（K值）、汁液损失、感官评价]以及鲢鱼体的阻抗变化率（Q值）,分析了Q值与各品质指标的相关性。结果显示,随贮藏时间的延长,鱼片的菌落总数、K值和汁液损失率逐渐增加,感官评分和鱼体的Q值逐渐减小。第15天鱼片的菌落总数为（6.85±0.07）log cfu·g-1,K值为（63.97±1.93）%,汁液损失率为（6.26±0.01）%,感官评分为10.0±1.4分,Q值为（22.92±2.60）%,此时鱼片失去食用价值。Q值与菌落总数、K值、汁液损失和感官评价的相关系数R分别为0.972、0.976、0.945和0.984（P〈0.01）,表明Q值与各鲜度指标具有良好的相关性。在0 ℃贮藏条件下用Q值可快速、无损伤地评估鲢鲜度。     

冰温结合保鲜剂贮藏对牙鲆鲜度和质构的影响

研究了冰温结合复合配方保鲜剂贮藏技术对褐牙鲆(Paralichthys olivaceus)鲜度和质构特征参数变化的影响,同时与单一冰温贮藏样品的相应变化进行了比较和分析.结果表明:冰温结合保鲜剂贮藏方法能够显著延缓牙鲆鱼肉样品细菌总数、K值、TVB-N和pH值等的增加速度;随着贮藏时间的延长,样品组织结构、破断强度和感官指标等的变化均呈现减缓趋势;与单一冰温贮藏条件的样品相比,冰温结合保鲜剂样品的货架期能有效延长10 d左右,达到最佳保鲜效果.     

枳实对南美白对虾健康的影响

通过在饲料中添加0．2％、0．5％、0．8％枳实来养殖南美白对虾，并对其体重增重率、体长增长率、超氧化物歧化酶(SOD)、氧化代谢产物丙二醛(MDA)、溶菌酶(LSZ)以及血淋巴细胞的吞噬能力进行测定，通过机体抗氧化系统和免疫系统，评价中草药枳实对南美白对虾健康情况的影响。结果表明：饲料中添加低剂量枳实可以显著改善SOD、吞噬活性和降低肌肉的MDA等指标，并对南美白对虾的免疫有一定的促进作用，但对生长的促进作用不大。     

春秋季节大棚南美白对虾养殖管理技术

目前在南美白对虾养殖过程中,利用大棚进行养殖成为了一种新的模式。通过利用大棚,不但可以解决养殖温度问题,也实现了春季和秋季两个季节都可以进行南美白对虾养殖,增加了南美白对虾养殖时间,提高了南美白对虾的养殖产量。基于对南美白对虾养殖过程的了解,以及春秋季大棚养殖方式的特点,我们应认真总结春秋季大棚南美白对虾养殖管理经验,并积极探索养殖管理技术,确保春秋季大棚南美白对虾养殖管理达到预期目标,提高春秋季大棚南美白对虾养殖效果。     

Estimation of variation of virulence of Renibacterium salmoninarum by survival analysis of experimental infection of salmonid fish

The variation of virulence of Renibacterium salmoninarum , the causative agent of bacterial kidney disease (BKD) in salmonid fish, was studied by infecting rainbow trout, Oncorhynchus mykiss (Walbaum), with two isolates (strains 325 and 932) from diseased Atlantic salmon, Salmo salar L., and one isolate (strain 4366) from an apparently healthy Atlantic salmon. Coho salmon, Oncorhynchus kisutch (Walbaum), were injected with the strain 932 to estimate difference in fish species resistance. Fish were removed by random sampling for other study purposes, a study design possible with analysis of lifetime distributions incorporating both sampling-, death- and survival-times. At the end of the experiment, the rainbow trout infected with strains 325, 932 and 4366 had a survival probability of 33%, 51% and 72%, respectively. The coho salmon infected with strain 932 had a 26% survival probability. The strain differences were significant according to the log-rank test, and the risk ratio between the strains ranged from 1·8 to 5·4. The strain from the apparently healthy fish was least virulent. The survival of the fish species was different over time. Rainbow trout were more likely to die early in the time course, but high numbers of coho died later, resulting in an overall risk of mortality of 1·4 in favour of rainbow trout. Differences in virulence may reflect changed selective pressure on R. salmoninarum when introduced from feral stocks into the environment of fish farms.     

Characterization of protease inhibitors of seminal plasma of cyprinids

Anti-proteinase activity was demonstrated in the seminal plasma of cyprinid fish species (bream, chub, ide, dace, asp, goldfish, roach, common carp) using electrophoretic techniques combined with a detection method based on inhibition of bovine trypsin. We found species-specific protease inhibitors in the seminal plasma of cyprinids. At least three bands of protease inhibitors with different migration rates could be identified by native PAGE. Higher variability was characterized for bands with slower migration rates. Visualization of inhibitors after SDS-PAGE under non-reducing conditions allowed estimation of their molecular weights. Apparent molecular weights were within the range of 51–59 and 47–54 kDa for the bands with slower and moderate migration rates, respectively. The molecular weight of fast migration bands for roach and common carp were estimated to 23 and 30 kDa, respectively. Inhibitors of common carp seminal plasma differed in their affinity toward serine proteases. Three inhibitors in common carp seminal plasma could be visualized using cod and bovine trypsin, but only two inhibitors (of high molecular weight) were recognized with chymotrypsin. There were differences in anti-proteinase activity and seminal plasma protein concentration in relation to the origin of common carp seminal plasma (breeding lines) and time of milt collection (spawning vs. post-spawning season).     

母猪胎衣不下的病因与防治要点

猪的胎盘属于弥散型胎盘,这种胎盘的结构特点和饲养管理的不当,常常导致母猪胎衣不下发生,给生猪的生产繁殖带来极大损失。本文针对母猪胎衣不下发生病因、综合防治进行详细阐述,旨在对预防和治疗胎衣不下能有所帮助。     

水硬度对七彩神仙鱼幼鱼发育的影响

采用不同硬度的水对七彩神仙鱼幼鱼进行饲养。6周龄幼鱼在硬度为7.94°dH±0.30°dH时饲养84d后,比在硬度为14.71°dH±0.23°dH水中的幼鱼个体大,生长速度快。表明较高硬度的水有利于七彩神仙鱼幼鱼的生长发育。     

虎斑乌贼受精卵卵黄营养成分分析

本实验对虎斑乌贼受精卵卵黄的营养成分进行分析,旨在探讨其幼体的营养需求量,为其幼体配合饲料研制提供参考数据。随机选取大约800个虎斑乌贼受精卵的卵黄,采用国家标准方法测定其水分、灰分、粗蛋白质、粗脂肪、氨基酸、脂肪酸和矿物元素含量。结果表明:1)虎斑乌贼受精卵卵黄中粗蛋白质含量为76.33%(干重基础);总氨基酸(TAA)和必需氨基酸(EAA)含量分别为71.22%和32.38%(干重基础),EAA/TAA为45.46%,氨基酸中以谷氨酸(Glu)含量最高(9.97%),必需氨基酸中亮氨酸(Leu)含量最高(7.58%)。2)其粗脂肪含量12.71%(干重基础);共检出17种脂肪酸,包括8种饱和脂肪酸(SFA)、5种单不饱和脂肪酸(MUFA)和4种多不饱和脂肪酸(PUFA),SFA、MUFA和PUFA分别占脂肪酸总量的43.47%、7.54%和49.25%,其中以DHA含量最高,达32.80%,EPA含量为7.70%,DHA/EPA为4.26。3)检测出Na、K、Ca、Mg、Sr、Mn、Fe、Cu、Zn、Al和As 矿物元素,微量元素中富含Zn、Al和Fe,含量分别为 0.77、0.71和0.43 mg/kg(鲜重基础)。由此可见,卵黄具有高蛋白、低脂肪,富含n-3PUFA的特点;虎斑乌贼幼体饲料中蛋白质需求量参考值为76.33%;氨基酸需求量参考值,如赖氨酸(Lys)为5.49%,蛋氨酸(Met)为2.63%;脂肪的需求量参考值为12.71%,DHA为4.17%,EPA为0.98%;微量元素需求量参考值,如Zn为2.77 mg/kg,Cu为0.19 mg/kg(干重基础)。     

头足类耳石微化学研究进展

耳石是位于平衡囊内起平衡作用的一对钙化组织,它是头足类的加速度感应器,记录其生命周期内的生物和生态信息。随着鱼类耳石微化学研究及应用的日趋成熟与完善,头足类耳石的相应研究也逐渐兴起。目前头足类耳石微化学的研究内容主要包括无机和有机大分子、微量元素、同位素、微化学标记等方面,其中微量元素是应用研究的重点,在头足类种群识别、生活史分析及栖息环境重建等方面发挥了重要作用。分析认为,头足类微量元素在与栖息环境尤其水温关系的研究中取得了很好的结果,被认为是测定头足类生活水温的温度计。然而,涉及种群识别、生活史分析以及与盐度和食物关系的研究还不够充分,且多集中于Sr/Ca的研究。因此,建议在今后的研究中要综合多种研究方法按时间和空间序列从日轮水平分析多种微量元素的含量与变化。     

不同品系盐生杜氏藻培养技术的研究

4种不同品系盐生杜氏藻培养结果表明：常温下,A33是最适宜培养的藻种,经4天培养,藻细胞密度可达到114×104cell／ml,细胞生长率达到0．369;其次是A23、A140、A5藻种,细胞生长率分别为0．317、0．314、0．234。控温条件下,4种品系杜氏藻细胞生长速度明显增高,是常温条件下的1．2倍。     

鱼类热忍耐温度研究进展

The paper is a review of the studies on the temperature of the thermal tolerance in fishes. It was described from four aspect: (1) The key parameters of temperature of thermal tolerance in fishes; (2) The influence factors of temperature of thermal tolerance in fishes; (3) The research methods of thermal effect of fishes; (4) The evaluation of effects of thermal pollution on fishes, especially, with the coastal power station will be‘built in China recent years, the effects of thermal discharge water on the marine fisheries resource wered iscussed.     

Histopathology of respiratory organs of certain air-breathing fishes of India

Air-breathing fishes have evolved bimodal respiratory mechanisms for exploitation of water (through gills and highly vascularized skin) as well as atmospheric air (through aerial respiratory organs, ABO). Mucous cells in these respiratory organs of variously stressed fishes exhibit periodic fluctuations in their density and staining properties. The main types of damage in the gills include congestion of blood capillaries (BLCs), periodic lifting and sloughing of respiratory epithelia of the secondary lamellae causing haemorrhage, extensive fusion of secondary lamellae and hyperplasia of the respiratory epithelia due to uncontrolled regeneration leading to asphyxiation, altered excretion, and death of the fish. Haemolysis has also been observed following lead exposure. The damage in the ABO of Heteropneustes fossilis includes sloughing of the epithelial cells, leading to haemorrhage causing decreased red blood corpuscles density and degeneration of the secondary gill lamellae with reduced respiratory area. Subsequent hyperplasia of the respiratory epithelia and fusion of gill lamellae increase the respiratory barrier distance. The BLCs often bulge out and protrude into the lumen, bringing blood nearer to air. The ladder-like pillar cell (PLC)-BLC components of the gill lamellae frequently collapse. Damage to the ABO of Channa striata is less severe. Often haemorrhaging due to bursting of extensively stretched BLCs causes aerial respiratory failure. Chloride cells of the ABOs also show hyperplasia. While the highly mucogenic epidermis of C. striata shows less damage, the epidermis of Clarias batrachus and H. fossilis shows severe wear and tear, sloughing, and haemorrhage. Side-by-side regeneration continues, causing altered histomorphology of the epidermis. The different gland cells also show periodic fluctuations in their density and staining. The dermis also shows severe damage with loosening of their connective tissue fibres. These fibres give stronger reactions for sulfated mucin that not only retain additional water molecules for continuance of skin breathing, but also bind the toxic ambient pollutants.     

牙鲆刺激隐核虫病的防治

2005年七、八月份,乐亭、滦南一带多家工厂化牙鲆养殖场发生刺激隐核虫病,此种病虫害发病急、传染快、死亡率高。发生过该病的养殖场牙鲆死亡率一般都在50％～80％之间,这种病害给牙鲆养殖业带来很大损失。