皮质醇混饲投喂对黄颡鱼幼鱼生长及外周血细胞的影响

采用皮质醇混饲投喂的试验方法,模拟自然条件下的慢性应激,观察和分析了应激激素皮质醇对黄颡鱼(Pelteobagrus fulvidraco)幼鱼生长和外周血细胞的效应。试验组饲料中皮质醇添加剂量为100 mg/kg,日投饵率为3%,试验期5周。结果表明:(1)外源皮质醇通过减少肠道黏膜皱褶和促进糖异生作用使黄颡鱼幼鱼增重受阻;(2)外源皮质醇使黄颡鱼幼鱼外周血白细胞数量显著减少、淋巴细胞百分比显著降低,但是中性粒细胞和单核细胞百分比则呈上升趋势;(3)外源皮质醇能促进红细胞增生,增加黄颡鱼幼鱼外周血红细胞数量。     

注射菌苗的生殖期黄颡鱼亲鱼的外周血细胞和体液免疫变化

阐明生殖期亲鱼在注射灭活菌苗后的血细胞和体液免疫变化规律，是预防亲鱼产后虚弱患病和仔鱼染病死亡的理论基础。本研究在试验组和对照组黄颡鱼胸鳍基部分别注射0.2 mL浓度为1.0×10⁸ CFU/mL福尔马林灭活温和气单胞菌苗（F-AS）和0.65%灭菌生理盐水，在免疫后第1、2、4、7、14、21、28、35天，从尾静脉采血，测定外周血液血细胞数量及组成比例，血细胞吞噬活性和抗体效价。结果显示：注射菌苗后白细胞数量和淋巴细胞的白细胞分类计数逐渐增加，显著高于对照；中性粒细胞、单核细胞的白细胞分类计数以及吞噬百分比（PP）、吞噬指数（PI）在4～7 d显著高于对照；抗体效价逐渐升高且在第14天达到最高，随后逐渐下降；而红细胞数和血栓细胞的白细胞分类计数逐渐下降，显著低于对照组。结果表明：单次注射菌苗后亲鱼可以产生良好的免疫应答，1～7 d以增强单核细胞和中性粒细胞等非特异细胞免疫为主；7～35 d淋巴细胞增值，并大量释放抗体且在第21天淋巴细胞出现极显著升高，此后虽逐渐下降但仍显著高于对照，抗体维持在较高水平上的时间为1周左右，建议在黄颡鱼催产前10～14 d进行单次菌苗注射以增强亲鱼免疫力。     

延迟投饵对瓦氏黄颡鱼仔鱼存活、摄食和生长的影响

以瓦氏黄颡鱼仔鱼为研究对象，将其分为15个处理组，每组200尾（各设3个平行组），分别在孵化后3、4、5、6、7．8、9、10、11、12、13、14、15和16d开始投喂大型涵，第15组为饥饿组，从不投饵。水温24．5～25．5℃，实验周期为30d。结果表明：（1）孵化后3d的瓦氏黄颡鱼仔鱼初次摄食，15日龄不能建立外源性营养的仔鱼进入PNR期，卵黄囊已耗尽。混合营养期持续4．12h。（2）瓦氏黄颡鱼仔鱼在不同饥饿阶段初次摄食率的变化为：开始较低，此后迅速上升，在4～10日龄达到高峰，最高初次摄食率为100％，此后逐步下降。（3）延迟5天投饵对瓦氏黄颡鱼仔鱼的存活率影响不显著，延迟6d投饵瓦氏黄颡鱼仔鱼的存活率随延迟投饵天数的增加而降低。延迟6d投饵，瓦氏黄颡鱼仔鱼的体长增长率随延迟投饵天数的增加而降低。     

黄颡鱼养殖技术

黄颡鱼（Pelteobagrusfulvidraco）隶属鲶形目，兢科，黄颡鱼属。广泛分布于我国大部分地区的天然水体中，喜集群，在弱光条件下摄食和活动。黄颡鱼以动物性饵料为主。在自然条件下，孵化出膜3～5d的鱼苗以自身的卵黄为营养，以后幼鱼以轮虫、枝角类、水蚯蚓等池塘底栖动物为食，成鱼阶段主食各种小鱼、虾；     

饲料中不同维生素E添加量对黄颡鱼幼鱼生长性能及免疫功能的影响

本研究探讨了饲料中不同维生素E添加量对黄颡鱼(Pelteobagrus fulvidraco)幼鱼生长和免疫的影响。在以鱼粉、豆粕为蛋白源的基础饲料中分别添加0mg/kg(对照组)、25mg/kg、75mg/kg、125mg/kg和175mg/kg的维生素E配成5种实验饲料。在水温(24.0±3.0)℃下,用上述实验饲料分别饲喂平均体质量约为5.1g的黄颡鱼幼鱼50d。实验结果表明,饲料中维生素E的添加量对黄颡鱼的特定生长率和饲料效率的影响不显著(P0.05);而添加量为175mg/kg时,黄颡鱼摄食率显著降低(P0.05);随着饲料中维生素E添加量的增高,黄颡鱼血浆超氧化物歧化酶(SOD)的活性未产生显著变化(P0.05);添加量为125mg/kg和175mg/kg时,血浆中丙二醛(MDA)的含量显著降低(P0.05);白细胞吞噬指数随添加量升高显著上升(P0.05),而吞噬百分率没有显著变化(P0.05)。综合以上结果,饲料中添加适量的维生素E可适当改善黄颡鱼的摄食,增强黄颡鱼的非特异性免疫力和抗氧化能力,从而提高动物的健康状况。推荐在黄颡鱼幼鱼饲料中添加125mg/kg的维生素E。     

黄颡鱼运输技术

黄颡鱼也称嘎牙子 ,是深受广大消费者欢迎的名优鱼类 ,也是近年来很受欢迎的高效养殖鱼类。在黄颡鱼人工养殖过程中会遇到黄颡鱼运输难度较大等问题 ,特别是鱼种和成鱼的运输。这主要是由于黄颡鱼具有三个硬刺 ,容易相互扎伤 ,以下介绍几种黄颡鱼运输技术供养殖户参考。1　鱼苗运输规格 3cm以下的黄颡鱼鱼苗适合采用尼龙袋充氧运输。尼龙袋规格一般为 75cm× 45cm ,采用双层尼龙袋 ,一个尼龙袋外面套另一个尼龙袋。内层尼龙袋加水 7～ 9kg ,将鱼苗通过漏斗倒入尼龙袋中 ,充氧并扎紧内层袋口 ,再扎紧外层袋口 ,装箱或装入布袋中。如果是夏季…     

复方中草药制剂对黄颡鱼长和非特异性免疫功能的影响

在基础饲料中添加0.5%、1.0%、2.0%的复方中草药制剂,连续投喂60d后,通过测定供试黄颡鱼的生长性能、血细胞的吞噬活性、血清溶菌酶活性,比较了复合中草药制剂对黄颡鱼促生长及非特异性免疫功能的影响。结果显示:饲料中添加0.5%的复方中草药制剂对黄颡鱼的生长影响显著(P0.05),添加1.0%和2.0%的中草药制剂对黄颡鱼的血细胞的吞噬活性、溶菌酶活力影响极显著(P0.01)。试验组可显著提高黄颡鱼生长、血细胞的吞噬活性、溶菌酶活力。     

黄颡鱼早期发育阶段摄食的研究

本实验采用实验生态学的方法，分别对池养9、13、17、23日龄黄颡鱼的食物组成，选食行为和昼夜摄食节律进行了研究。结果表明，黄颡鱼早期发育阶段主要摄食浮游动物，其食物组成随仔稚鱼的生长而变化。摄食初期（黄颡鱼9日龄时）主要食物为枝角类和轮虫，其中枝角类数量和重量百分比分别为86.71%和89.65%，占绝对优势。之后，黄颡鱼的摄食范围进一步扩大，从23日龄开始，由主要选食枝角类转为主要选食桡足类，桡足类所占数量百分比也从初期的3.29%上升到23日龄时的26.68%；而且，从13日龄开始，摇蚊幼虫等底栖动物所占比重呈上升趋势，从初期的54.84%到23日龄的69.52%，始终在食物组成中占主要优势。黄颡鱼摄食具有明显的昼夜节律性，9日龄时摄食高峰值出现在20:00（897.7），低峰值出现在19:00（161.8）；13、17、23日龄仔稚鱼胃平均饱满指数均于4:00达最高峰（914.1、1113.1和199.7），于19:00、19:00和16:00达最低值，分别为50.9、60.9和76.6，夜间时段摄食水平显著高于白天时段，黄颡鱼仔稚鱼明显表现为晚上摄食类型。     

黄颡鱼人工养殖技术（四）

由于这个阶段黄颡鱼主要以水中的浮游动物为食。因此，要保持池水的肥度，当透明度大于40cm后，适时追肥。为了保证黄颡鱼在成鱼阶段能良好地利用人工配合饲料．从这个阶段起，可以适量投喂海大黄颡鱼鱼种的粉状饲料．将粉状料拌水捏成团，投放在固定的食台上．每天早晚2次，投喂量占鱼体重的3％～5％。由于黄颡鱼喜集群摄食．因此不要到处乱投，避免饲料浪费。     

黄颡鱼鱼种成鱼池塘轮养技术试验

正黄颡鱼(Pelteobagrus fulvidraco)属鲇形目,鲿科,黄颡鱼属,俗称黄嘎牙、黄骨鱼,具有适应能力强、生长快、营养高、肉质细嫩、鲜美的优点,近年来,深受居民和养殖户的喜爱。河南省郑州市古荥镇南王庄村一垂钓休闲渔场根据市场需求,2014年在渔场内利用一面积为3 468.4 m~2的池塘开展黄颡鱼鱼种、成鱼池塘轮养试验,在6—12月饲养大规格黄颡鱼鱼种,第2年的1—7月饲养黄颡鱼成鱼。共出塘大规格黄颡鱼鱼种1 426.6 kg,平均出塘     

运输对养殖黄颡鱼血液生化和肌肉物性分析指标的影响

测定了在10.4~11.2℃下运输4 h后不同时间(0 h、1 h、3 h、6 h、12 h、1 d、3 d、7 d和20 d)养殖黄颡鱼(Pelteobagrus fulvidraco)血液生理生化指标和肌肉物性分析指标的变化。结果显示,运输引起了黄颡鱼血清皮质醇和血糖浓度的显著升高(P0.05),在运输结束12 h后恢复到正常水平。运输后鱼体血清超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活性和总抗氧化能力(T-AOC)均有显著性升高,随着恢复时间的推移逐渐回降到正常水平;但过氧化物酶(POD)活性并未出现显著性差异,维持稳定的水平。运输后肌肉硬度、弹性、胶黏性、凝聚性、咀嚼性、回复性等物性分析指标均显著性降低。除了凝聚性和咀嚼性之外,其他肌肉物性分析指标在运输结束72 h后恢复到正常水平。研究表明,长途运输造成了养殖黄颡鱼的应激反应,对肌肉物性特征产生了显著的影响,但运输后的恢复可使鱼体抗氧化能力和肌肉物性分析指标回复到正常水平。     

Effects of dorsal aorta cannulation on the stress response of channel catfish (Ictalurus punctatus)

The stress response to dorsal aorta cannulation and serial blood sampling was examined in the channel catfish Ictalurus punctatus. Channel catfish cannulated and repetitively sampled once a day for 7 days did not exhibit a change in response to surgery or to the 24h sample regime as measured by plasma cortisol, glucose, and chloride. In fish that were either serially bled (0, 1, 3, 6, 9, 12, 24, and 48h) immediately after surgery or allowed to recover 6 days before being serially bled, overall plasma cortisol levels were higher than those of fish bled every 24h. Catfish serially bled immediately after surgery had significantly higher plasma glucose levels compared with catfish allowed to recover from surgery 6 days before serial sampling. Although channel catfish recover from cannulation surgery in 24h, a longer recovery period may be needed prior to serial sampling if the samples are taken more frequently than every 24h.     

柱形病对黄颡鱼血液生化指标的影响

为探究柱形病对黄颡鱼(Pelteobagrus fulvidraco)生理机能的影响,随机选取患病和健康黄颡鱼各10尾,采集其血液,静置后离心分离血清以测定血液生化指标如皮质醇、乳酸(LD)含量,乳酸脱氢酶(LDH)、碱性磷酸酶(ALP)活性,葡萄糖、白蛋白(ALB)、总蛋白(TP)、尿素氮(BUN)、总胆固醇(TCHO)、高密度脂蛋白胆固醇(HDLC)、低密度脂蛋白胆固醇(LDLC)含量,谷草转氨酶(AST)、谷丙转氨酶(ALT)活性。结果显示:患病黄颡鱼血清皮质醇浓度和LDH、AST活性均极显著高于健康鱼,LD含量和ALT活性显著高于健康鱼。与健康鱼相比,患病黄颡鱼血清葡萄糖含量极显著降低,而HDLC、LDLC、TCHO、ALB、TP、BUN浓度和ALP活性无显著差异。健康鱼肝细胞呈近圆形,形状较规则,细胞界线清晰,细胞核多位于细胞中央,呈圆形或椭圆形,肝细胞以中央静脉为中心形成放射状排列。患病鱼肝细胞出现局部坏死、空泡化,形成坏死灶,伴有大量中性粒细胞、淋巴细胞浸润。结果表明:柱状黄杆菌感染可引起黄颡鱼鱼体显著的应激反应,并引起鱼体肝脏损伤。     

Stress in African catfish (Clarias gariepinus) following overland transportation

Of the many stressors in aquaculture, transportation of fish has remained poorly studied. The objective of this study was therefore to assess the effects of a (simulated) commercial transportation on stress physiology of market-size African catfish (Clarias gariepinus). Catfish weighing approximately 1.25 kg were returned to the farm after 3 h of truck-transportation, and stress-related parameters were measured for up to 72 h following return. Recovery from transportation was assessed through blood samples measuring plasma cortisol, glucose and non-esterified fatty acids (NEFA) and gill histology. Also, the number of skin lesions was compared before and after transport. Pre-transport handling and sorting elevated plasma cortisol levels compared to unhandled animals (before fasting). Plasma cortisol levels were further increased due to transportation. In control fish, plasma cortisol levels returned to baseline values within 6 h, whereas it took 48 h to reach baseline values in transported catfish. Plasma glucose and NEFA levels remained stable and were similar across all groups. Transported catfish did not, on average, have more skin lesions than the handling group, but the number of skin lesions had increased compared to unhandled animals. The macroscopic condition of the gills was similar in control, transported and unhandled catfish; however, light microscopy and immunohistochemistry revealed atypical morphology and chloride cell migration normally associated with adverse water conditions. From our data, we conclude that transportation may be considered a strong stressor to catfish that may add to other stressors and thus inflict upon the welfare of the fish.     

Effect of yeast polysaccharide on some hematologic parameter and gut morphology in channel catfish (Ictalurus punctatus)

A study was conducted to investigate the effect of dietary yeast polysaccharides on some hematologic parameters and intestinal morphology of channel catfish. Channel catfish were fed diets containing yeast polysaccharides at 0 (control), 0.1, 0.2, or 0.3?% for 7?weeks. Each diet was provided to 10 channel catfish specimens (5.82?±?0.13?g initial weight) replicated 3?times in individual 250?L fiberglass tanks. Some hematologic parameters, leukocyte phagocytic activity, and intestinal morphology were monitored. After 7?weeks of trial, 0.2?% yeast polysaccharides resulted in significantly higher (P?相似文献   

Reduction of transport stress of ayu by obligated schooling

We investigated stress responses of ayu Plecoglossus altivelis under the hypothesis that overcrowding during transport can be a stressor and the stress predisposes fish to disease by decline in immunocompetence. The extent of stress response was determined under different fish densities. As inferred from the serum concentration of cortisol 1 day after the treatment, the density at more than 23 kg/m³, which was within the range of normal transporting procedures, acutely evoked intense stress responses. To examine a possible way to reduce the stress response of fish under crowding conditions, we compared two fish groups established in water tanks with circulating (whirling) and turbulent currents at the same density. The cortisol levels 1 day after the treatment were 2.5-fold higher in turbulent current than in whirling current. Fish in whirling current formed a school, while those in turbulent current aggregated with each other. Schooling of fish induced by water flow may reduce their stress responses during transport. A transport system with a directional water flow should keep fish in good condition without reducing the number of fish contained.     

黄颡鱼头肾的组织发生与组织结构研究

为深入了解黄颡鱼的免疫机能,采用组织学方法,对孵化后1～48 d的黄颡鱼鱼苗头.肾的组织发生进行了观察;对5月龄幼鱼和成鱼头肾的组织结构进行了观察.结果表明,出膜后1 d,头肾仅由肾小管组成;出膜后2d,头肾小管间出现未分化的细胞团;出膜后7 d,头肾小管间出现淋巴细胞团;此后淋巴细胞及造血细胞的数量逐渐增多;出膜后26～43 d,肾小管逐渐萎缩直至完全消失,头肾完成由排泄器官向淋巴器官的转变.黄颡鱼头肾含丰富的静脉血管、血窦以及处于不同发育时期的各类免疫细胞.肾上腺组织细胞分布于头肾门静脉以及头肾组织中静脉管周边.其幼鱼头肾所含酸性颗粒细胞较成鱼头肾丰富,而成鱼头肾则具有较多的黑色素巨噬细胞,且常常在血管附近聚集形成黑色素巨噬细胞中心.     

The response of coral trout (Plectropomus leopardus) to capture, handling and transport and shallow water stress

The stress response of coral trout (Plectropomus leopardus ) to wild capture or controlled shallow water stressors was investigated. Stress associated with capture from the wild, handling and transport and shallow water evoked significant changes in circulating levels of cortisol, glucose, lactate, haemoglobin (Hb) and haematocrit (Hct) in coral trout. Plasma glucose, Hb and Hct increased over 30 to 60 min in response to the controlled stressor and then returned toward unstressed levels, even if the stressor persisted. Cortisol increased to maximum levels over the 60 min following the onset of the stressor and remained elevated for 4 h in the case of a single 30 min shallow water event or 3 d in response to the capture, handling and transport. The difference between the responses of blood glucose and cortisol suggests that cortisol does not maintain blood glucose during stress in coral trout. The concentrations of circulating thrombocytes, lymphocytes and granulocytes were also significantly affected by shallow water stress. As lymphocytes and granulocytes are important immune components, reduced concentrations of these cells may explain the increases in disease susceptibility, commonly observed in stressed fish during live transport.