鱼类鳃病及其防治技术

鱼类鳃病,按其致病病原体可分为细菌性烂鳃病、真菌性烂鳃病(又称鳃霉病)、寄生虫性鳃病。 细菌性烂鳃病是常见的传染性鱼病,常与细菌性肠炎病、赤皮病并发,严重危害草鱼鱼种、成鱼,一旦暴发,草鱼死亡率高达60％以上,同时也严重威胁青鱼、鲢鱼和鳙鱼。近年来随着高密度、集约化养殖方式的迅     

浅谈养殖鱼类烂鳃病的防治

池塘高密度集约化养鱼高产、高效,这是不争的事实。但由于苗种投放密度大,喂料多,水质难控制,也极易发生鱼病。在我县地塘养鱼中,养殖鱼烂鳃病较多,其中尤以鲤鱼的发病率最高,而且死亡率也最高,造成的经济损失最为严重。经过连续观察,发现患病的不单纯是细菌性烂鳃,多数伴有指环虫、车轮虫和孢子虫等寄生虫的侵袭。因此,在烂鳃病的防治上就不能只使用传统的漂白粉、富氯等药物,还应适当搭配杀虫药物进行防治。经过多年的探索和实践,我们积累了一些具体的经验和方法,现介绍如下:     

鱼类鳃病防治方法

鱼的鳃病种类很多。不少养鱼户盲目用药，这样不仅贻误治疗时机，还造成药害。因此，在防治鱼类鳃病时．应查颜观鳃，准确诊断，及时治疗。     

精养池塘鱼类常见鳃病的防治方法

鱼生活在水中,靠鳃吸入水中的溶解氧,水中存在的大量病原体生物很容易感染到鳃上。鳃的发病率很高,因此有“养鱼先养水,治病先治鳃”之说。鱼的鳃病种类很多,为了准确诊断、合理用药,笔者凭着多年从事水产工作的经验,将鳃病分为以下6大类,以期为水产业同行提供借鉴和参考。1　营养性鳃病1 1　症状鳃丝弯曲,鳃小片曲屈、萎缩,排列不整齐。1 2　病因由于饲料中缺乏泛酸或其它营养不平衡引起,使鱼体免疫能力下降,易引起细菌感染,寄生虫侵入。1 3　防治方法合理调配精饲料,做到氨基酸、不饱和脂肪酸、钙、磷、维生素和微量元素及多项营养指…     

鱼类鳃病的病因与防治

鳃是鱼类的重要呼吸器官，鱼体与外环境的气体交换主要由鳃来完成。鳃发生病变鱼类呼吸不畅。必然影响鱼类的正常代谢和生长。当鱼的鳃患病影响了鱼类的正常呼吸，鱼体会通过自身调节提高呼吸运动节律来弥补病鳃气体交换的不足，当鳃的气体交换量降低到不能维持最低生命活动需要时，鱼类就会发生窒息死亡。因此，防治鱼类鳃器官的常见病、多发病，十分重要。下面将引起鳃发生病变的主要原因和防治方法分述如下。     

浅谈鱼类鳃病及其防治措施

近年来随着水产养殖业的迅速发展，养殖逐渐向高密度、集约化方式发展。养殖中各种病害危及到水产业的生产，影响产量和经济收入。鳃病是常见的鱼病。常与细菌性肠炎病，赤皮病并发。发病严重的鱼类往往死亡率高达40％（草鱼达60％以上），严重影响集约化、高密度水产养殖的进一步发展。现就几年鱼类鳃病在我县内发生流行情况和防治措施总结如下：     

鱼类的白头白嘴病、烂鳃病及其防治方法

白头白嘴病、烂鳃病都是食用鱼类和观赏鱼类的常见病、多发病。每年流行季节长，如不及时采取有效防病措施，往往引起幼鱼和成鱼大批死亡，不但造成经济上的损失，影响观赏鱼类品种的选育，而且还严重影响金鱼出口创汇任务的完成。现将中国科学院水生生物研究所鱼病室的硒究成果，以及笔者在各地推广应用所取得的经验，简要介绍，供各地参考、     

鱼类鳃病的综合防治

鳃病是鱼病中最常见的一种疾病，其病因是：病菌、霉菌、原虫、吸虫、化学物质污染、缺乏某些营养物质等造成的。要防治鱼的鳃病，必须根据病因采取综合性防治措施。     

鱼类鳃病及防治

笔者结合近几年在鱼类鳃病防治方面的一些见解与经验,对各种鳃病的防治做一介绍。一、细菌性烂鳃一般我们说的烂鳃病就足指细菌性烂鳃病,又称“乌头瘟”。本病是草鱼最重要的常见病害之一,且常与肠炎、赤皮病并发,使病情复杂化,成为通常所说的“草鱼三病”。其主要症状有三个：开天窗、头发黑、鳃上有淤泥。病鱼行动缓慢,反应迟钝,常离群独游。     

鱼类大红鳃病的危害及其防治

大红鳃鱼病是当地群众俗称.从2010年以来,该病从海南、广东、江苏、浙江等局部精养鱼区暴发扩散,其来势凶猛,流行甚速.加之并发水污染,特别是有机物污染,带来病菌、霉菌、病毒及有机毒害物质的严重侵袭,遭至鱼类死亡率达60％左右,有的几乎全军覆灭,对淡水养鱼业带来严重的威胁,如2011年海南和广东罗非鱼病死事故以及2012年以来江苏省大丰、射阳、兴化等集约化养鲫损失惨重.     

养殖鱼类寄生虫病防治新途径探讨

总结了近年来养殖鱼类寄生虫病防治处方用药情况,包括内服吡喹酮、联合用药和生态调控等方法,在预防治疗养殖鱼类寄生虫病上获得较好效果。并指出现行防治方法存在的问题,提出了外虫内治、联合用药和依靠生态调控等手段的寄生虫病防治新途径。     

高铁酸盐复合剂在水质净化和鱼病防治上的应用

高铁酸盐是近年来国际上流行的环保型消毒杀菌剂，己被广泛应用于工业工程水处理，饮用水，农牧渔业上杀菌、除藻、防腐、保鲜等方面。作者将高铁酸锶复合剂应用于虾、蟹、鳗、鳜、鲈等饲养，在大面积推广中取得了良好的效果。本文着重介绍该合剂的作用原理，以期在渔业上得到更好的应用。     

Gill morphometry of the red drum,Sciaenops ocellatus

The structure and morphometry of the gills of the marine teleost, red drum, have been studied. The present analysis of gas exchange area of fish gills is one of the most intensive and the results are compared to less intense averaging methods. Based on the gill area estimates, red drum falls into the category of a fish of intermediate activity. Its gill clearly has an exchange area less than that of the tunas, but is slightly greater than that of trout or bass. The three components that contribute to total exchange area (filament length, lamellar density, and area of individual lamellae) are not all greater in species with a greater total exchange area. The best correlate is total filament length.     

扁玉螺鳃的形态学研究

用光镜和扫描电镜观察了扁玉螺鳃的组织学和表面结构,鳃叶上皮由５个区带的细胞组成,即前纤毛柱状细胞,立方细胞,侧纤毛柱状细胞,后纤毛柱状细胞及呼吸上皮。侧纤毛是产生呼吸水流的动力来源,呼吸上皮细胞表面凹凸不平,其组织学和表面结构有助于进行气体交换。     

Gill disease of marine fish caused by infection with Neoparamoeba pemaquidensis

Amoebic gill disease (AGD) of maricultured salmonids, turbot, Scophthalmus maximus (L.), European seabass, Dicentrarchus labrax (L.), and sharpsnout seabream, Diplodus puntazzo (Cetti), caused by Neoparamoeba pemaquidensis has been reported from Australia (Tasmania), Ireland, France, Chile, North America (Washington State and California) and Spain. Of the salmonids, Atlantic salmon, Salmo salar L., appears to be the most susceptible with rainbow trout, Oncorhynchus mykiss (Walbaum), also suffering significant disease. Only minor outbreaks have been reported in coho, O. kisutch (Walbaum), and chinook salmon, O. tshawytscha (Walbaum). The disease now accounts for 10–20% of production costs of Atlantic salmon in Tasmania and has lead to temporary abandonment of culture of this species in parts of Spain. It is of lesser, but still significant, importance in other countries. Much is known about the pathology of AGD but the pathophysiology of the disease is poorly understood. There is evidence that non-specific immunity is involved in fish acquiring resistance to AGD, but no unequivocal evidence exists for protection as a result of specific immune responses. To date, for salmonids, the only effective treatment for AGD is a freshwater bath. Control procedures based on modification of management strategies have been minimal and virtually unresearched.     

鲤鱼鳃组织结构及鳃对重金属离子的耐受性

采用不同浓度的重金属对鲤鱼进行不同时间的中毒试验，构成了鳃组织的耐量试验。试验表明，当超过鳃的耐受量时，鳃发生了不同阶段的病变。在低浓度短时间作用下，鳃组织分泌的粘液增多。随着浓度的增加和时间的延长，鳃组织出现鳃血管扩充、充血，呼吸上皮肿胀，鳃小片呈棍棒状，相邻几条鳃丝发生融合，形成一片细胞板。有些鳃细胞脱离。病状严重时造成鳃小片坏死、解体导致鳃功能的损害和破坏。     

菲律宾蛤仔鳃组织的原代培养

以菲律宾蛤仔的鳃组织为材料,经除菌、剪碎后,将组织块接种到培养瓶中,分别用E-MEM和M199培养基进行了原代培养。结果表明,两种培养基均可满足菲律宾蛤仔鳃组织培养的要求,在M199培养基中添加0 5%的水解乳蛋白、10%的小牛血清、0 35%的NaCl和青-链霉素双抗液,可获得更好的培养效果,鳃细胞能正常迁出和增殖。     

缢蛏鳃的光镜与扫描电镜研究

用光镜和扫描电镜观察了缢蛏鳃的组织学和表面结构。鳃丝有主鳃丝和普通鳃丝之分,鳃丝表面有前纤毛和侧纤毛,分别与食物的运送和呼吸水流的产生有关。普通鳃丝的扁平细胞为呼吸上皮。相邻鳃丝通过含有血管的丝间连接连系,相邻的鳃小瓣通过隔膜状的瓣间连接连系。两根主鳃丝之间的12~22根鳃丝由簇内连接连接成簇。     

壬基酚对1月龄泥鳅的急性毒性及鳃、肝脏组织学损伤研究

为了研究壬基酚(Nonylphenol,NP)对淡水鱼类幼鱼的急性毒性及相关组织的损伤效应,选取平均体质量6.0 g、平均体长9.2 cm的1月龄泥鳅(Misgurnus anguillicaudatus)为受试材料,检测壬基酚对幼鱼的急性毒性效应,按等对数间距法,将NP设置为1.69、1.95、2.25、2.60、3.00 mg/L共计5个浓度处理组进行急性毒性实验,同时设置空白对照组,每组设3个平行样,每个样投放10条泥鳅,观察NP对泥鳅鳃、肝脏组织结构的损伤变化,并统计半致死浓度和安全浓度。结果表明,壬基酚对1月龄泥鳅24、48、72、96 h的半致死质量浓度分别为3.722、2.939、2.466、2.175 mg/L,安全浓度为0.550 mg/L。组织学切片观察显示,壬基酚高浓度处理使泥鳅鳃小片细胞脱落严重,鳃小片变细;泥鳅肝脏细胞出现空泡、肿大、核脱落等现象,细胞间隙变大,边界模糊。实验表明,壬基酚属于高毒性酚类污染物,对1月龄泥鳅的毒性作用随着暴露浓度增加、作用时间的延长而增强,在高剂量暴露下可造成泥鳅鳃和肝脏组织的严重损伤。     

Investigation of co‐infections with pathogens associated with gill disease in Atlantic salmon during an amoebic gill disease outbreak

Gill diseases are a complex and multifactorial challenge for marine farmed Atlantic salmon. Co‐infections with putative pathogens are common on farms; however, there is a lack of knowledge in relation to the potential effect co‐infections may have on pathology. The objective of this study was to determine the prevalence and potential effects of Neoparamoeba perurans, Desmozoon lepeophtherii, Candidatus Branchiomonas cysticola, Tenacibaculum maritimum and salmon gill poxvirus (SGPV) during a longitudinal study on a marine Atlantic salmon farm. Real‐time PCR was used to determine the presence and sequential infection patterns of these pathogens on gill samples collected from stocking until harvest. A number of multilevel models were used to determine the effect of these putative pathogens on gill health (measured as gill histopathology score), while adjusting for the effect of water temperature and time since the last freshwater treatment. Results indicate that between 12 and 16 weeks post‐seawater transfer (wpst), colonization of the gills by all pathogens had commenced and by week 16 of marine production each of the pathogens had been detected. D. lepeophtherii and Candidatus B. cysticola were by far the most prevalent of the potential pathogens detected during this study. Detections of T. maritimum were found to be significantly correlated with temperature showing distinct seasonality. Salmon gill poxvirus was found to be highly sporadic and detected in the first sampling point, suggesting a carryover from the freshwater stage of production. Finally, the model results indicated no clear effect between any of the pathogens. Additionally, the models showed that the only variable which had a consistent effect on the histology score was N. perurans.