共查询到20条相似文献,搜索用时 59 毫秒
1.
春季水温开始上升,过了冬的鱼类逐渐开始摄食,活动力增强。但是,一些淡水鱼类寄生虫也开始大量繁殖,其中,斜管虫就是其中一种。近来,一些常见淡水鱼类例如:桂花鱼、草鱼和淡水白鲳等经常出现斜管虫病,该病发展很快,死亡率很高,如不及时控制死亡率超过百分之八十。由于在冬季鱼类活动力差,斜管虫在鱼鳃部缓慢繁殖,虫体活力也不强,并不表现出症状,但水温一上升,病鱼就开始出现体表粘液增多,鳃部有一些泥巴粘物的症状,在池塘边慢游,解剖鳃部镜检,能看到大量斜管虫活体,即可诊断为斜管虫病。 相似文献
2.
3.
低温季节是斜管虫病的高发季节,淡水鱼类斜管虫的病原体有鲤斜管虫和十六线斜管虫两种,常见的为鲤斜管虫,现结合专著及各文献资料对斜管虫病的症状及防治方法做一综述。1流行情况与生活方式斜管虫病为低温性寄生虫病,大多文献资料认为此病多发生在春秋季,每年3~5月份和10~12月份是此病的流行季节。 相似文献
4.
5.
1996年11月中旬和12月下旬,在广西柳州市沙塘园艺场水产公司淡水白鲳鱼种越冬池内先后发生过小瓜虫病和斜管虫病,由于发现得早及治疗措施得当,没有造成大的损失,只有在发生斜管虫病时死了几尾鱼种,过程如下:一、小瓜虫病症状及治疗1.症状:11月13日上午在喂鱼时发现白鲳鱼种不摄食,而前两天鲳鱼种都抢食较狠,经观察,发现鱼种成堆在池角集中,鱼不时跳出水面,鱼体不断地和增氧机缆绳磨来擦去。捞出两条鱼种,刮取体表粘液和鳃上粘液在10×4倍的显微镜下观察,发现两鱼的鳃上和体表都带有不同数量的有明显香肠形大核的小瓜虫。2.… 相似文献
6.
7.
欧鳗斜管虫病的防治 总被引:1,自引:0,他引:1
今年 ,我省几家养鳗场新投放的欧鳗苗种 ,先后遭受斜管虫的侵袭。由于斜管虫寄生于欧鳗体上 ,未曾报道过 ,养殖户对该寄生虫病的症状及防治方法不甚了解 ,造成很大损失。在此将斜管虫的发生情况及防治方法介绍如下 :1 病原体为鲤斜管虫。属纤毛纲 ,全毛目管口科。虫体侧面观为背面隆起 ,腹面平坦 ;腹面观呈卵形 ,左右两边不对称 ,活体在后端往往稍凹入。腹面两边各有几条长短不一的纤毛线 ,腹面前中部有一个喇叭状的口管。大核近园形。虫体大小 4 0× 2 5~ 6 0×4 7μm。虫体的传播靠直接接触或胞囊。2 危害及症状主要危害欧鳗的白苗。… 相似文献
8.
在实际养殖过程中,由于周围环境条件限制和高密度精养,养殖水体水质恶化,鱼体抗病能力下降,容易突发疾病。近年来淡水养殖鱼类特别是罗非鱼,经常出现斜管虫病,该病发展快,一旦发生,如不及时控制,死亡率超过80%以上。一、病原斜管虫病病原体为鲤科斜管虫,属管口目、斜管 相似文献
9.
随着草鱼苗种和成鱼集约化养殖的发展,草鱼病害日趋增多。江苏省涟水县水产工作站在近几年的渔业科技人户工程中,发现斜管虫的危害程度逐步加剧。许多草鱼苗种塘或个别成鱼塘大规模暴发斜管虫病,给养殖户带来很大损失。 相似文献
10.
11.
12.
13.
为了解淡水鱼类寄生虫的研究现状及前沿热点,为该领域研究工作的开展提供科学量化的参考依据,以Web of Science(WOS)核心合集数据库收录的1980—2020年共1 088篇相关文献为数据样本,运用VOSviewer和CiteSpace可视化软件绘制了淡水鱼类寄生虫研究的发文量、发文地区、发文作者、发文机构、关键词频次和突现状况等知识图谱,并对发文趋势和研究热点进行了分析。结果表明,淡水鱼类寄生虫研究领域的发文量总体呈上升趋势,2009年后上升趋势明显;淡水鱼类寄生虫的研究受到广泛关注,巴西、捷克和美国是淡水鱼类寄生虫领域的研究中心;捷克共和国科学院、墨西哥国立自治大学和新西兰奥塔哥大学等3个机构是淡水鱼类寄生虫领域的高产研究机构;Poulin R、Scholz T和Salgado-Maldonado G等3位研究人员是淡水鱼类寄生虫研究的核心力量;发文国家间和机构间形成了良好且稳定的合作关系,但研究者间合作关系较为分散,缺少跨团队合作;International Journal for Parasitology、Parasitology Research、Parasitolo... 相似文献
14.
P. A. Larkin 《Ecology of Freshwater Fish》1992,1(1):1-4
Abstract– Projected world population increases imply demand for an increase of 60 million tonnes on the present world fish production of 100 million tonnes. Capture fisheries are unlikely to yield more because many stocks are already overexploited, there are few remaining unexploited and management shows few signs of redressing problems. Aquaculture is a possible source of the required production, given maintenance of current rates of increase. If this potential is to be realized, the importance of maintaining the quality of freshwater, brackish and coastal marine environments can scarcely be overstated. In a world of rapid change, there is an urgent need for research at all levels of biological and social organization that relate to the ecology of freshwater fish. At the organismic level, genetics, migratory behaviour and physiological ecology will be emphasized. Population genetics research is needed to enlighten controversies concerning the impact of cultural practices and the effects of harvesting natural populations. Greater attention will be given to interactions between species, including fish and their parasites, and the dynamics of multispecies interactions in pond culture and in capture fisheries. Issues of multiple uses of water resources will force research on freshwater fish ecology into broader contexts. The march of discovery in all branches of science will have major implications for freshwater fisheries research. The next few decades will be demanding of the creative energies of young researchers. 相似文献
15.
16.
17.
18.
19.
Current status of parasitic ciliates Chilodonella spp. (Phyllopharyngea: Chilodonellidae) in freshwater fish aquaculture 下载免费PDF全文
《Journal of fish diseases》2017,40(5):703-715
Freshwater fish farming contributes to more than two‐thirds of global aquaculture production. Parasitic ciliates are one of the largest causes of production loss in freshwater farmed fishes, with species from the genus Chilodonella being particularly problematic. While Chilodonella spp. include ‘free‐living’ fauna, some species are involved in mortality events of fish, particularly in high‐density aquaculture. Indeed, chilodonellosis causes major productivity losses in over 16 species of farmed freshwater fishes in more than 14 countries. Traditionally, Chilodonella species are identified based on morphological features; however, the genus comprises yet uncharacterized cryptic species, which indicates the necessity for molecular diagnostic methods. This review synthesizes current knowledge on the biology, ecology and geographic distribution of harmful Chilodonella spp. and examines pathological signs, diagnostic methods and treatments. Recent advances in molecular diagnostics and the ability to culture Chilodonella spp. in vitro will enable the development of preventative management practices and sustained freshwater fish aquaculture production. 相似文献
20.