浮萍在观赏鱼饲料中应用的研究进展

浮萍是一种分布广泛的小型漂浮水生植物,具有生长能力旺盛,富含赖氨酸与类胡萝卜素等优点。观赏鱼的营养需求全面,且需要着重于鱼体的健康与体色的增艳增色。本文归纳分析观赏鱼对于蛋白质营养需求、体色色素沉积影响因素,浮萍的蛋白质含量、氨基酸组成以及色素含量,对浮萍作为新型观赏鱼人工配合饲料原料进行展望,为浮萍的进一步开发利用提供参考。     

天然增艳物质对池塘养殖锦鲤体色的影响研究

<正>对锦鲤而言,体色是影响其市场价格的主要因素,因此,如何提高体色的观赏价值是锦鲤研究的重点之一。目前的许多研究表明,光照、生理状况、饲料营养等多种因素都能影响到鱼的体色。而在同一品种中,饲料对体色的影响更为突出。鱼类可利用类胡萝卜素作为肌肉和皮肤的着色剂,但是鱼类自身不能合成这些色     

着色剂在水产养殖中的研究与应用

<正>随着我国水产养殖业的迅速崛起,人工养殖水产品的品质问题越来越受到人们关注,其中色泽是影响其商品价格和观赏价值的重要因素。水产动物呈现出的斑斓色彩,在很大程度上受类胡萝卜素的影响,而水产动物自身不能合成类胡萝卜素,必须从食物中摄取。水产动物日粮的主要原料含类胡萝卜素很少,而现代高密度集约化养殖条件下,人工养殖的水产品体色往往缺乏天然水产品所具有的健康色泽,从而使其商品价值大打折扣。因此,在饲料中添加着色剂,对养殖鱼类的体色进行调控,已成为现代水产养殖业的重要技术之一。     

淡水观赏鱼常见种类及养殖技术

<正>近年来,随着人们生活质量的提高,观赏鱼养殖越来越受到人们的喜爱。但是养殖观赏鱼也需要一定的科学知识和养殖经验,若养殖不当,会给养殖者带来经济损失甚至精神上的压力。本文着重介绍了家庭养殖淡水观赏鱼常见的种类和养殖技术,以及常见疾病的防治,从而解决养鱼爱好者在观赏鱼养殖中存在的误解。观赏鱼只是指那些具有观赏价值的有鲜艳色彩或奇特形状的鱼类。世界的鱼类,据说有3~5万种,其中可供观赏的包括海水鱼,淡水鱼有2~3千种,而实际普遍饲养     

鱼类着色剂及其在黄颡鱼饲料中的应用

本文浅述了鱼类体色形成机制、鱼类着色剂类胡萝卜素及其在黄颡鱼配合饲料的应用、影响鱼类着色的因素等研究进展,以期对黄颡鱼配合饲料的研发提供一定理论参考。     

水产品增色剂

水产品增色剂西南农业大学水产系林仕梅罗莉叶无土随着现代水产养殖业的发展，由于大量使用人工配合饲料，养殖周期缩短，导致某些养殖鱼类的体色变淡（如鲑鱼、鳟鱼、罗非鱼、真鲷、对虾），无法与天然捕捞的鱼虾的色泽相比，影响商品价格。此外，观赏鱼的体色也被人们所...     

“水中活宝石”——锦鲤

锦鲤在世界上享有水中活宝石的美誉。锦鲤为鲤科鱼类,它具有鲜艳似锦的色彩,变幻多姿的斑纹,是种大型观赏鱼类。锦鲤源于中国,制种改良于日本,历经多年的杂交选育目前已形成13个品系100多种,以红白,大正,昭和三色为主要代表品种。其中红白锦鲤是最具权威与尊贵的品种,被日本推为国鱼,价值上万元。     

鱼类的体色及其调控

鱼类在自然环境条件下都有其各自特定的体色.体色不仅是鱼类分类的重要特征,也是其健康状态的衡量标准,同时体色正常与否也直接影响商品鱼的价格.鱼类的体色特征由遗传因素决定,是真皮层下面的各种色素细胞互相配合、互相作用的反映.鱼类色素细胞主要包括黑色素细胞、黄色素细胞、红色素细胞和虹彩细胞.体色变化主要受神经和内分泌调控.鱼类的年龄和性别、食物组成以及生存环境的变化会引起鱼类体色的变化.在人工养殖条件下,往往由于养殖环境剧烈变化、或使用缺乏有效天然色素源的饲料等因素,导致养殖鱼类体色异常,使其失去所特有的天然颜色和光泽.文章综述鱼类体色的形成机理及其变化的影响因素.同时,试图探讨养殖生产中鱼类体色异常的调控方法.     

金鱼畅销有妙招

以色动人:金鱼是名贵的观赏鱼。金鱼的体色是人们欣赏金鱼的主要内容之一。如果所上市的金鱼色彩鲜明花团锦簇,就可以刺激消费者的购买欲望。 要使金鱼色彩明丽的方法有二:一是所饲养的金鱼要在淡绿色水中生长和发育,并投喂枝角类等活饵     

日本利用类胡萝卜素对水产动物增色的研究进展

本主要介绍了日本在利用类胡萝卜素（carotenoid)等色素源物质改善人工饲养的五条Shi、真鲷和锦鲤等养殖鱼类体色的研究结果，现有的研究结果表明，在水产动物的饲料中添加一定量的糊胡萝卜素对人工饲养水产动物具有明显地增色作用。     

Heartworm in dogs in Canada in 1984

In late December 1984, 1853 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1984 and 35% of them responded. Veterinarians reported that 97,794 dogs were blood-tested to check for microfilariae and 1417 dogs (1.45% of those tested) were found with heartworm. Another 34 dogs were amicrofilaremic, but were diagnosed as having heartworm disease, to give the total number diagnosed in 1984 as 1451 (1.48%). Heartworm was reported from all provinces except Prince Edward Island and Newfoundland but most (1310) of the cases were in Ontario. In Quebec, 126 cases were reported mostly from west of Montreal.

Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 27% of the cases were observed with clinical signs of heartworm disease and 72% had a history of not having left Canada. Southwestern Ontario continued to be the primary focus of the infection.

     

Heartworm in dogs in Canada in 1983

In late December 1983, 2 800 veterinarians across Canada were sent a questionnaire in order to assess the status of heartworm disease in Canada in 1983 and 26% of them responded. Veterinarians reported that 59 504 dogs were blood-tested to check for microfilariae and 771 dogs (1.30% of those tested) were found with Dirofilaria immitis. Heartworm disease was diagnosed in all provinces except New Brunswick and Newfoundland but most (733) of the cases were in Ontario.

Heartworm disease was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 31% of the cases were observed with clinical signs of heartworm disease and 64% had a history of not having left Canada. Southwestern Ontario continues to be the focus of the infection and most of the dogs there had not left the province previously.

     

Heartworm in dogs in Canada in 1991

In late November 1991, 1883 clinics in Canada were sent a questionnaire to assess the status of Dirofilaria immitis in dogs in 1991 and there was a 60.0% response. There were 344,031 dogs tested for heart-worm (HW), 627 were found infected and the prevalence of HW infection was 0.18%. There were 417 dogs with HW in Ontario, 116 in Manitoba, 38 in Quebec, 53 in British Columbia, three in Alberta, and one in Nova Scotia. In British Columbia, all of the infected dogs but one were from the Okanagan valley which, as from 1991, is a new focus of infection in Canada. Most dogs with HW had not been on preventive medication in 1990, and the prevalence among dogs tested and unprotected was 0.59%. That prevalence was considerably higher in endemic areas. Companion dogs, over three years of age and maintained primarily outdoors in rural areas, were most frequently infected. One cat was diagnosed with D. immitis and 33 dogs had Dipetalonema reconditium.     

Heartworm in dogs in Canada in 1985

In late December 1985, 1485 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1985 and 44% of them responded. Veterinarians reported that 137,300 dogs were blood-tested to check for microfilariae and 1210 dogs were found with heartworm. Another 36 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number diagnosed in 1985 as 1247 (0.91%).

Heartworm was reported from all provinces except Prince Edward Island, Newfoundland and Saskatchewan but most (1126) of the cases were in Ontario. Southwestern Ontario continued to be the primary focus of the infection in Canada. From Quebec, 91 cases were reported mostly from and around Montreal. From Manitoba, 19 cases were reported from Winnipeg and surrounding areas. Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 28% of the cases were observed with clinical signs of heartworm disease and 78% had a history of not having left Canada.

     

Heartworm in dogs in Canada in 1988

In late November 1988, 1581 small and mixed animal clinics and institutional veterinarians across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1988, and 46% of them responded. Veterinarians reported that 181,577 dogs were blood-tested for heartworm disease and 367 dogs were found with D. immitis microfilariae. Another 60 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number of cases diagnosed in 1988 as 441 (0.24%).     

Heartworm in dogs in Canada in 1989

In late November 1989, 1732 clinics and institutional veterinarians were sent a questionnaire to assess the status of Dirofilaria immitis, and 51.7% responded. Of 247,716 dogs tested, 394 had D. immitis microfilariae and 51 were amicrofilaremic for a total of 445 cases and heartworm prevalence of 0.17%. Most (408) of these dogs had no preventive medication and the prevalence among dogs tested and unprotected was 1.01%. That prevalence was considerably higher in endemic areas. Thirty-seven dogs with heartworm had preventive medication. Heartworm was most frequent in companion dogs over three years of age maintained outdoors in rural areas. About 75% of the cases had never left Canada, 26% had clinical signs and 125 were not treated.

Heartworm was reported from British Columbia, Manitoba, Ontario, Quebec, Nova Scotia and Newfoundland, but 383 cases were in Ontario. South-western Ontario was the primary focus of infection. There were 33 cases in Quebec and 24 in Manitoba, mainly found in and around Metropolitan Montreal and Winnipeg respectively.

     

Heartworm in dogs in Canada in 1987

In late November 1987, 1246 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1987, and 50% of them responded. Veterinarians reported that 165,428 dogs were blood tested for heartworm disease and 511 dogs were found with D. immitis microfilariae. Another 78 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number of cases diagnosed in 1987 as 589 (0.35%).     

Heartworm in dogs in Canada in 1986

In late December 1986, 1224 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1986; 46% of them responded. Veterinarians reported that 150,989 dogs were blood-tested for microfilariae and 869 dogs were found with heartworm. Another 65 dogs were amicrofilaremic but diagnosed with heartworm disease and one was found with heartworm at necropsy to give the total number diagnosed in 1986 as 935 (0.62%).

Heartworm was reported from Manitoba, New Brunswick, Ontario and Quebec, but most (810) of the cases were from Ontario. South-western Ontario continued to be the primary focus of the infection in Canada. There were 103 cases reported from Quebec, mostly from and around Montreal, and 21 cases from Manitoba, from Winnipeg and surrounding areas. Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 33% of the cases were observed with clinical signs of heartworm disease and 81% had a history of not having left Canada.