Control of the Parasitic Copepod Caligus elongatus on Pond-Reared Red Drum

Abstract

Red drums Sciaenops ocellatus that became infested with the copepod Caligus elongatus during rearing in seawater ponds were successfully treated with a 20-min freshwater dip after harvest and before being stocked in the wild. This treatment killed all copepods. Short-term (30min) and long-term (18-h) treatments with Copper Control, trichlorfon, and formalin were less effective than fresh water.     

圈养珍稀野生动物肠道寄生虫感染情况及其形态观察

对陕西省野生动物驯养繁育技术中心的3种圈养珍稀野生动物进行了肠道寄生虫感染情况、种类及形态的调查。采用生理盐水涂片及碘液染色法,对3种52只(头)野生动物的粪便进行检查,并对检出的寄生虫进行数码显微摄片,结果共检出肠道寄生虫17种。红腹锦鸡(Chrysolophus pictus)、孔雀(Pavo muticus)、野猪(Sus scrofa)寄生虫总感染率分别为84.2%、77.8%、80%,以芽囊原虫(Blastocystis sp.)、赖利绦虫(Raillietina sp.)、蛔虫(Ascaridia sp.)、艾美耳属球虫(Eimeriasp.)感染较为突出。     

Lesions Associated with Attachment of the Parasitic Copepod Phyllothyreus cornutus (Pandaridae: Siphonostomatoida) to Interbranchial Septa of Blue Sharks

Abstract

Lesions associated with the parasitic copepod Phyllothyreus cornutus on the interbranchial septa of blue sharks Prionace glauca were observed in detail. Female copepods were associated with grossly visible, soft, papillomatous lesions on the interbranchial septum in which their second antennae were embedded. Attached male copepods were either not associated with any appreciable lesions or were attached within shallow ulcerations. Histologically, the papillomatous lesions were marked by epithelial hyperplasia over a lamina propria replaced by granulation tissue or fibrosis with lymphoid nodules. Lesions associated with male copepods consisted of epithelial ulceration and subacute, necrotizing, heterophilic branchitis. Lesions associated with female copepods appeared suggestive of long-term local attachment whereas those associated with males were suggestive of more ephemeral associations with the fish. The observed lesions did not appear capable of impairing respiration; however, the overall impact of Phyllothyreus cornutus infections on the well-being of the blue shark remains unknown.     

Demonstration of the Specificity of the Salmonid Hurnoral Response to Renibacterium salmoninarum with a Monoclonal Antibody against Salmonid Immunoglobulin

Abstract

The specificity of the antibody response of salmonids to Renibacterium salmoninarum antigens was demonstrated by western blotting techniques that utilized a monoclonal antibody against salmonid immunoglobulin. In this study, the specificity of the response in immunized chinook salmon Oncorhynchus tshawytscha was compared with the response in naturally infected chinook salmon and coho salmon O. kisutch, and immunized rabbits. The antibody response in immunized salmon and rabbits and the naturally infected fish was primarily against the 57–58kilodalton protein complex. In addition to recognizing these proteins in the extracellular fraction and whole-cell preparations, antibody from the immunized salmon and rabbits detected four proteins with lower molecular masses. Western blotting techniques allow identification of the specific antigens recognized and are a useful tool for comparing the immunogenicity of different R. salmoninarum preparations. Immunofluorescent techniques with whole bacteria were less sensitive than western blotting in detecting salmonid anti-R. salmoninarum antibody.     

鲑甲病毒的传入风险评估

目前我国尚未有发现鲑甲病毒(SAV)感染的相关报道。如果SAV随进口贸易的鱼类进入我国,会给我国的水产养殖业造成很大的损失。为了保障我国水产养殖业的健康发展,针对进境水生动物种类开展了SAV跨境传播的风险评估,并提出了科学的风险管理措施。综合风险分析认为,我国传入SAV的主要威胁是来自疫区的活的大西洋鲑、褐鳟鱼和虹鳟,其次是冰冻和冰鲜的大西洋鲑、褐鳟鱼和虹鳟。建议对活的、冰冻和冰鲜的易感鱼类以及用做鲜活饵料的鱼类,禁止从疫区进口;鱼肉、加工后的制品以及其它非易感鱼类是低风险的,可以自由贸易;对运输活鱼的水、包装等要进行强制常规消毒,无需检测。     

The Control of Parasitic Nematodes in Commercial Piggeries in Kenya as Reflected by a Questionnaire Survey on Management Practices

Tropical Animal Health and Production -     

Prevalence of Infectious Pancreatic Necrosis Virus on Salmonid Fish Farms in Spain

Abstract

In Spain, salmonid fish farming was commercially developed in the 1960s, and now there are 140 private farms that depend heavily on imported embryonate eggs. Infectious pancreatic necrosis was first clinically diagnosed in Spain in 1970, but the virus (IPNV) was not isolated and identified until 1980. Since that time, researchers have isolated IPNV from other samples in Spain. A diagnostic survey was conducted to determine how prevalent IPNV is on fish farms in Spain and whether the virus has been responsible for some of the major financial losses occurring every year on these farms. In total, 236 samplings of rainbow trout Oncorhynchus mykiss from 31 farms in eight hydrographic areas were done over a 3-year period. Infectious pancreatic necrosis virus was isolated in 94 cases, and serotyping of the viral strains revealed that 81% of these isolates were strain Sp and 19% were strain Ab. Neither IPNV strain VR-299 nor rhabdovirus (as infectious hematopoietic necrosis virus or viral hemorrhagic septicemia virus) was detected in any of the samples.     

Effect of Pollution on Fish Diseases: Potential Impacts on Salmonid Populations

Abstract

Anthropogenic factors have contributed to the precipitous decline of wild Pacific salmon stocks, although the mechanisms and processes at work are largely unknown. Pollution may be one of these factors. Sediments in estuaries are known to act as repositories for contaminants, and estuaries are important habitats for ocean- and river-migrating salmon. We have shown that juvenile salmon Oncorhynchus spp. and their prey bioaccumulate chlorinated hydrocarbons and aromatic hydrocarbons—important classes of toxic xenobiotics. Furthermore, we have shown that exposure to these pollutants can lead to immunosuppression and increased disease susceptibility in juvenile salmon. Whether pollution influences natural disease outbreaks in host populations, including salmon, is currently unknown. It is postulated that the occurrence of disease depends on the interaction of the host, the environment, and the pathogen. Absence of pathogens would reduce the potential for adverse environments to influence disease outbreaks. However, a recent reconnaissance survey of juvenile chinook salmon Oncorhynchus tshawytscha from Oregon coastal rivers revealed that pathogens were an integral component in all systems studied, although the prevalence of the pathogens varied. Furthermore, recent studies of natural fish populations have demonstrated that infectious-disease-induced mortality can significantly reduce the size of the host population. By creating adverse environments (e.g., polluted estuaries) which alter the susceptibility of the host to pathogens that are integral and ubiquitous components of the habitat, pollution increases the probability of disease-related impacts on fish populations.     

动物寄生虫病的综合防治研究进展

动物寄生虫病是由寄生于动物体的各种病原性寄生虫引发的疾病,由于寄生虫常以一种极为隐蔽的方式对动物进行慢性消耗,因而严重影响畜牧业的快速发展。因为单一防治措施对寄生虫病的控制和消灭很难凑效,所以综合防治措施的发展愈来愈重要。本文就动物寄生虫病对动物的危害、抗动物寄生虫药物的新剂型和综合防治措施等方面进行了综述。     

Parasitic disease of the bovine nervous system

Parasitic disease of the nervous system of cattle is mainly caused by migrating nematodes, expanding cestode cysts, or by rickettsiae and protozoa in the central nervous system. Common parasitic causes of neurologic diseases in cattle in the United States are Hypoderma larvae, toxins produced by Dermacentor ticks, and metabolic changes associated with intestinal coccidiosis.     

桑天牛卵啮小蜂Aprostocetus prolixus的寄生生物学研究

桑天牛卵啮小蜂 (Aprostocetusprolixus)是一个新种 ,对桑天牛有较高的寄生率。观察发现该寄生蜂 1年 2～ 3代 ,老熟幼虫以休眠状态越冬。 6月下旬越冬代的成虫开始羽化 ;第 1代成虫 7月下旬开始羽化 ,8月上中旬为盛期 ;第 2代幼虫一部分以老熟幼虫直接越冬 ;第 2代成虫 8月下旬至 9月中旬羽化 ,8月底与 9月初为盛期 ,所产小蜂幼虫从 9月中下旬开始陆续以老熟幼虫在寄主体内越冬。探明了该寄生蜂的羽化时间、交配、产卵、寄生等行为习性。     

寄生原虫DNA解旋酶家族研究进展

寄生原虫是一类单细胞真核生物,是人和动物疾病的重要病原之一,给人类健康和畜牧业发展造成了严重的危害。DNA解旋酶是一类参与几乎所有生物DNA代谢的重要解旋酶,目前原虫DNA解旋酶的研究主要集中在恶性疟原虫,且被报道的DNA解旋酶多为人类或酵母的同源物,其保守基序与人类、酵母等都存在差异,是研究抗原虫药物的重要潜在靶标。笔者主要综述了经典解旋酶的保守结构域及其功能特点,介绍了各个解旋酶的极性与偏好底物等生化特性,汇总了已报道原虫DNA解旋酶的种类。目前报道的DNA解旋酶大多集中在恶性疟原虫,其中疟原虫含18种,利士曼原虫含3种,布氏锥虫和兔脑原虫均含2种,弓形虫含1种。同时介绍了目前原虫中较为引人关注DNA解旋酶：RecQ家族、DEAD-box家族、UvrD解旋酶家族和RuvB家族的功能研究进展,其中DEAD-box家族中有3种疟原虫特异性解旋酶PfPSH1/H2/H3并未在宿主人类中发现相似物,另一种解旋酶UvrD则与人类、小鼠、秀丽隐杆线虫等无同源性,而与细菌、真菌等同源性较高。笔者对原虫DNA解旋酶的基本特性和功能进行综述,阐述了目前原虫DNA解旋酶的研究进展及其作为药物靶标的可能...     

《动物寄生虫病防治》实验学习现状分析

通过对动物医学专业学生的问卷调查,从学生对《动物寄生虫病防治》实验的学习兴趣、学习目的、实验准备情况、实验操作及实验报告完成情况5个方面分析了学生对该课程的实验学习现状,并对教学中存在的问题提出了改进措施和意见。     

Predicted Redistribution of Ceratomyxa shasta Genotypes with Salmonid Passage in the Deschutes River,Oregon

Abstract

A series of dams on the Deschutes River, Oregon, act as migration barriers that segregate the river system into upper and lower basins. Proposed fish passage between basins would reunite populations of native potamodromous fish and allow anadromous fish of Deschutes River origin access to the upper basin. We assessed the potential redistribution of host-species-specific genotypes (O, I, II, III) of the myxozoan parasite Ceratomyxa shasta that could occur with fish passage and examined the influence of nonnative fish on genotype composition. To determine the present distribution of the parasite genotypes, we exposed eight salmonid species—three native and five stocked for sport fishing—in present and predicted anadromous salmonid habitats. We monitored fish for infection by C. shasta and sequenced a section of the parasite ribosomal DNA gene from fish and water samples to determine parasite genotype. Genotype O was present in both upper and lower basins and detected only in steelhead Oncorhynchus mykiss. Genotype I was spatially limited to the lower basin, isolated predominately from Chinook salmon O. tshawytscha, and lethal for this species only. Genotype II was detected in both basins and in multiple species, but only as a minor component of the infection. Genotype III was also present in both basins, had a wide host range, and caused mortality in native steelhead and multiple nonnative species. Atlantic salmon Salmo salar and kokanee O. nerka were the least susceptible to infection by any genotype of C. shasta. Our findings confirmed the host-specific patterns of C. shasta infections and indicated that passage of Chinook salmon would probably spread genotype I into the upper Deschutes River basin, but with little risk to native salmonid populations.

Received April 20, 2012; accepted July 19, 2012