几种淡水鱼血清免疫复合物含量与其抗病能力关系的研究

采用2．0％和3．5％PEG沉淀法,研究了鲫鱼、草鱼、鳙鱼、鲶鱼和罗非鱼血清免疫复合物。统计结果表明,免疫复合物含量在同一鱼类的不同PEG浓度处理间均有显著差异;在不同鱼类的同一PEG浓度处理间,除鳙鱼和鲶鱼间无显著差异外,其余均有显著差异。实验发现,血清免疫复合物的含量变化与各种淡水鱼在分类上的地位及抗病能力明显相关。     

8种淡水鱼类血清蛋白质的初步研究

通过乙酸纤维素薄膜电泳,分离了8种鱼类的血清蛋白质成份并测定了其各组成份的相对含量。着重比较了γ球蛋白含量的差异性。     

几种淡水养殖鱼类血清溶菌酶活性的初步观察

溶菌酶作为鱼类的非特异性免疫(先天性免疫)物质之一,在鱼体抵抗感染性致病菌的最前沿防御机制中起着重要作用。现已知,溶菌酶是一种呈抗生性的、由淋巴球分泌的溶解性酶,并主要作用于革兰氏阳性菌(G~+菌)     

几种印度淡水鱼的保鲜研究

本文研究了露西塔野鲮Labeo rohita,麦瑞加拉鲮Cirrhinus mrigala和莫桑比克罗非鱼Tila.pia mossambica在常温(29～32℃)下和冰藏时的质量变化,露西塔野鲮和莫桑鼻给罗非鱼在常温下10小时后完全腐败,而麦瑞加拉鲮在11小时后腐败。感官鉴定,总挥发性盐基氮和细菌总数的测定表明,露西塔野鲮(0.5千克或以上)和麦瑞加拉鲮(0.5千克或以上)在村有棕榈小垫的普通竹篮中冰藏7～8天质量尚可,而莫桑鼻给罗非鱼(30～40克)只能冰藏6天。露西塔野鲮冰藏时,其鱼体大小对货架寿命的影响研究表明,小于500克的鱼在普通容器串冰藏6天是可被允许的,而那些小于1千克的鱼可冰藏8天,若将聚乙烯薄膜衬在普通容器中,可使露西塔野鲮的贮存期由6天延至8天。由预冷后再冰藏,露西塔野鲮的货架寿命可达9天,比单单只有冰藏的鱼延长了货架寿命2天。     

日本对虾血清凝集素及其免疫作用的初步研究

用日本对虾（Penaeus japonicus)亲虾的血清与11株弧菌和7种脊椎动物的红细胞进行凝集反应实验，其中，溶藻弧菌HW283的凝集效价最高，达4096，而产气弧菌和海蛹弧菌的凝集效价最低，仅为8；与红细胞的凝集结果显示，对虾血清与大白鼠，小白鼠，豚鼠的红细胞反应较强，与鸡、人、山羊、兔的红细胞反应较弱，表明日本对虾血清中存在自然凝集素，养成期的日本对虾经弧菌菌苗免疫后，对该致病菌株的抵抗力获得提高，病原感染组，对照组和菌苗免疫组的对虾血清分析对豚鼠，大白鼠和小白鼠红细胞的凝集强度皆为感染组＞对照组＞免疫组。     

几种淡水鱼的凝胶特性

近年来,我国水产品总产量连续几年位居世界第一,其中以淡水鱼的增幅最大。但目前,由于水产品的深加工没有跟上,淡水养鱼面临销售不景气的困扰,因此解决好水产品的保鲜、加工、销售等问题,是关系到水产业继续发展的重要课题。 为了探讨淡水鱼在鱼糜制品方面的发展可能性,笔者在1990年留学日本期间,曾对6种淡水鱼的凝胶特性进行过研究,现整理发表如下。     

酶法提取4种淡水鱼鱼鳞胶原蛋白的研究

对4种常见淡水鱼鱼鳞的基本成分和氨基酸组成进行了测定,研究了酶解鱼鳞制备水解胶原蛋白的工艺,并采取正交试验对水解条件进行了优化。试验结果表明,淡水鱼鳞主要由蛋白质和灰分组成,粗蛋白含量高达55%以上;氨基酸组成显示淡水鱼鳞羟脯氨酸含量丰富,是制备水解胶原蛋白的良好原料。正交试验结果表明,55℃、E/S3%、酶解2h、料液比1∶10(即底物质量浓度为100g/L)时水解效果最好,此时,水解产物分子量较小,且分布集中。     

介绍淡水鱼养殖的几种模式

齐齐哈尔金三角渔场是齐齐哈尔市最大的渔场。金三角渔场有养殖场9个,总精养面积7000亩,年产商品鱼300万千克,占齐齐哈尔市市场销售量的70%以上;鱼种100万千克。主要的养殖品种有:鲤鱼、鲫鱼、草鱼、鲢、鳙和鲑鳟鱼。有自己的饲料加工厂(威望饲料厂),所产饲料3万吨(其中水产饲料1万吨。)通过十几年的养殖摸索,我们摸索出适合当地养殖条件的几种淡水鱼养殖模式。今介绍淡水鱼类养殖的四种模式,供大家参考借鉴。一、大水面以吃食鱼为主的驯化养殖我们渔场应地势建成了一个很有特色的大水面养殖塘。面积1500亩,平均水深0.9米,注排水方便。设投…     

几种淡水鱼内脏油脂提取的工艺条件

以草鱼、鳊、鲢三种高产的淡水鱼内脏的提取油脂原料，着重研究内脏油脂的提取工艺条件。研究中采用隔水蒸煮法提取油脂，以出油率和油脂的质量指标为评价依据，通过正交试验初步确立时间、温度和加碱量等主要影响因素，优选出较佳的提取淡水鱼内脏油脂的工艺条件，从而为扩大试验提供论据。     

几种淡水鱼在冻藏过程中鲜度变化研究

本文以淡水养殖的鲢，鳙、罗非鱼为对象，利用ＩＱＦ冻结设备在－３０℃下冻结，并在－１８℃的冷藏冻中贮成．通过对鱼肉鲜度指标Ｋ值，ＶＢＮ、ＦＡＡ－Ｎ、ｐＨ值以及蛋后质变性指标的测定，探讨鱼肉在冷冻贮藏过程中质量的变化情况．实验结果表明，Ｋ值和ＡＴＰａｓｅ活性对反映淡水鱼低温冻藏过程中的鲜度变化有着良好的规律性。     

鱼类体液免疫因子研究进展

同高等脊椎动物一样 ,鱼类也是通过免疫系统来抵御外来病原生物的侵害 ,通过非特异性和特异性的免疫防御机制来维持机体的正常功能及自身内环境的稳定。但是 ,近年来鱼类病害发生频繁 ,其中某些疾病给水产养殖业造成灾难性的危害。这就使得免疫防治技术在鱼病防治中呈现出日趋广阔的应用前景[1] 。因此 ,对鱼类特别是重要的经济鱼类免疫系统的研究受到国内外学者的广泛关注。鱼类的免疫系统是鱼体执行免疫功能的机构 ,是产生免疫应答的物质基础 ,由免疫器官、免疫细胞和体液免疫因子组成。本文着重就鱼类体液免疫因子的研究进展作一概述 ,包…     

Outbreak of betanodavirus infection in tilapia, Oreochromis niloticus (L.), in fresh water

A betanodavirus associated with a massive mortality was isolated from larvae of tilapia, Oreochromis niloticus , maintained in fresh water at 30 °C . Histopathology revealed vacuolation of the nervous system, suggesting an infection by a betanodavirus. The virus was identified by indirect fluorescent antibody test in the SSN1 cell line and further characterized by sequencing of a PCR product. Sequencing of the T4 region of the coat protein gene indicated a phylogenetic clustering of this isolate within the red-spotted grouper nervous necrosis virus type. However, the tilapia isolate formed a unique branch distinct from other betanodavirus isolates. The disease was experimentally reproduced by bath infection of young tilapia at 30 °C. The reservoir of virus at the origin of the outbreak remains unidentified. To our knowledge, this is the first report of natural nodavirus infection in tilapia reared in fresh water.     

A feasible method for humane slaughter of eel (Anguilla anguilla L.): electrical stunning in fresh water prior to gutting

It was observed that farmed eels could be rendered unconscious and insensible instantaneously by passing an electrical current through fresh water. The general epileptiform insult on the EEG was characterized by a tonic/clonic and an exhaustion phase. After stunning, the ECG (electro‐cardiogram) revealed fibrillation. The electrical stunning parameters were on average 194 ± 4 V and 0.636 ± 0.040 A/dm² for 1.6 ± 0.4 s. Within a confidence level of 95%%, taking into account the number of animals with a reliable EEG (n = 29), at least 93% of all eels are effectively stunned in fresh water by an average current of 0.636 ± 0.040 A/dm². The behaviour of groups of five eels, which were able to move freely in the water was observed before and after stunning with 50 V and 0.17 A/dm². After 3‐s stunning, two eels were turned upside down. They changed to a normal position after 10 and 13 s respectively. Subsequently, all eels were very active in swimming behaviour and stopped swimming after 75 s. When stunned for a longer duration, all eels were turned upside down and stopped breathing for a limited period of time. In the last experiment the eels were stunned in fresh water (500 μS) with a voltage of 200 V for approximately 1 s, which was followed by 50 V for 5 min. As soon as the stunning started the water was de‐oxygenated by flushing nitrogen to kill the eels by suffocation during the period of unconsciousness and insensitivity. The oxygen saturation decreased from 74 ± 10 to 23 ± 11% at 22 °C. After stunning no brain activity and no responses to pain stimuli were observed on the EEG. The heart rate increased (P < 0.05) after stunning, which was followed by a significant decrease. Only 1 out of 18 eels returned partially from upside down to a normal position 2 h after stunning; however, the eel did not respond to pain stimuli in behaviour. The developed stunning procedure can be recommended for humane slaughter of 50‐kg batches of eels.     

硝化细菌对淡水水族箱水质及养殖观赏鱼影响的初步研究

本试验设立硝化细菌、水生观赏植物对照组与空白对照组进行对比试验。结果表明硝化细菌对降低淡水水族箱中COD、NH4^ -N、NO^2 -N效果显。有利于提高蓝毛足鲈等的相对生长率，对孔雀鱼、七彩神仙鱼增色有益。实验中还发现硝化细菌有明显预防细菌性肠炎病发生的作用。硝化细菌在淡水水族箱中固着种群稳定需要25—28天，在施用硝化细菌3—4周后水体COD、NH4^ -N、NO^2 -N达到稳定水平。     

水温对不同鱼类的急性致死效应

采用半静态急性毒性实验方法,设置不同温度梯度对四种海洋鱼类按突然升温和逐步升温两种方式进行96h热冲击实验。结果显示:在突然升温情况下大黄鱼、鮸鱼、黑鲷和鲻鱼的96h-UILT50值分别为33.00℃、32.40℃、35.00℃和36.19℃;在逐步升温的情况下大黄鱼、鮸鱼、黑鲷和鲻鱼的96h-UILT50分别为32.72℃、33.47℃、36.40℃和37.11℃。突然升温试验结果表明,四种受试鱼类中鮸鱼对高温耐受能力最差,大黄鱼对高温的忍耐能力也较差,黑鲷对高温冲击的耐受能力较强,鲻鱼耐受能力最强;逐步升温试验结果表明,四种受试鱼类中大黄鱼对逐步升温的耐受能力最差,鮸鱼对逐步升温的忍耐能力也较差,黑鲷对逐步升温冲击的耐受能力较强,鲻鱼耐受能力最强。现场温度下逐步升温方式对不同受试生物的影响程度明显小于突然升温方式。     

Study of a sand smelt (Atherina boyeri Risso 1810) population reproducing in fresh water

A population of sand smelts, Atherina boyeri, lives in the Camargue wetland, southeast France. This study deals with the part of the population that migrates towards the Fumemorte drainage canal, flowing into the brackish lagoon, the Etang du Vaccarès. Between autumn and early spring, some sand smelts migrate from the canal into seasonally flooded freshwater marshes, where they breed, and then leave between March and July, just before the marshes dry out. The sand smelts remaining in the canal use the vegetation-choked smaller branches of the canal for breeding. In summer, most of the sand smelts leave freshwater habitats for the Vaccarès. Male and female sand smelts reach a maximum age of 4 years (5 winters), have the same weight and show a peak in condition in spring. Breeding occurs from March to July. Sand smelts are multiple spawners and batch fecundity increases with the female size. The mean egg diameter is independent of the female length but decreases towards the end of the spawning season. Sand smelts feed mainly on zooplankton and secondarily on benthic invertebrates. Temporary marshes are richer in submerged macrophytes needed for spawning and have lower densities of fish than the canal. In these marshes, sand smelts feed on the large forms of zooplankton that develop because of the low fish abundance. The life-history traits of this population of A. boyeri living in fresh water in Camargue indicate that this environment is not unfavourable for this species. This study showed that this species can undertake local migrations to colonize various habitats. The adaptability of A. boyeri favours its survival in very unstable Mediterranean environments.     

环境胁迫对鱼类免疫系统影响的研究概况

环境胁迫(environmental stress)是指环境对鱼类所处的生存状态产生的压力,可以分为急性环境胁迫和慢性环境胁迫。捉捞(handling)和干扰(disturbance)等引起急性环境胁迫,而水质逐渐恶化和高密度放养等造成慢性胁迫。随着世界人口的增长和消费水平的提高,世界渔业也得到了长足的发展。但与此同时,由于人类活动范围的扩大、程度的加深,     

软质饲料与鲜杂鱼饵料饲养大黄鱼对比试验

为比较研究网箱养殖大黄鱼过程中分别投喂软质饲料与鲜杂鱼饵料的养殖效果,2011年5月于福建省马鼻玉井网箱养殖海区,选取平均规格为152 g/尾的大黄鱼,经过60 d的饲养,试验组全投软质饲料,对照组全投鲜杂鱼。结果显示：试验组与对照组每尾平均体重分别为256.9 g、231.3 g,饲料系数分别为2.505、7.306,大黄鱼每增重1 kg所需的饲料成本分别为15元、19.7元,投喂软质饲料进行饲养可节省成本4.7元。结果表明：投喂软质饲料的养殖效果优于鲜杂鱼,存活率更高,更具环保等综合效益。     

淡水养殖新宠—厚颌鲂

厚颌鲂是我国长江上游地区的特有鱼类,具有很高的营养价值。目前,在厚颌鲂的成鱼单养及人工繁殖的研究方面取得了较好的效果,为厚颌鲂的养殖推广奠定了基础。