【作者】 曾朝辉；

【导师】 华育平； 王永林；

【作者基本信息】 东北林业大学 ， 动物学， 2003， 硕士

【摘要】 鲟鱼苗早期暴发性疾病给鲟鱼养殖业带来了巨大的损失。本论文旨在寻找导致暴发性疾病发生的原因。通过对暴发病流行状况多次细致深入的调查，在清楚了其发病规律和病理变化的基础上，制定了周密的研究方案。研究结果如下：细菌、寄生虫检查结果为阴性。取病鱼脏器制成组织液，人工感染健康鱼，没有出现死亡。肝、脾、肾、脑等组织病原生物检查没有发现病毒和真菌。用多种抗菌和抗病毒药物进行预防和治疗，没有取得明显的疗效。将健康鱼放入病鱼池中混养，最后发病死亡。说明本病具有一定的传染性。对健康鱼不投食或只喂颗粒料的饥饿实验发现，开口驯化时拒食颗粒料引起的饥饿，与暴发病有一定关系，可能起到诱发或促进的作用。对鱼场水质、生物饵料水蚯蚓和病鱼各脏器重金属含量分析测定，结果显示：水质正常，后两者Hg、Pb、Cd含量均非常高，尤其是Hg。说明蓄积于病鱼组织中的重金属来源于受污染的水蚯蚓。Hg急性毒性实验，表明Hg对鲟鱼苗的96小时LC50值为0.50145 mg╱L，95％置信区间(0.09765～0.76016)。慢性毒性实验确定了长期接触该毒物可以引起机体危害的阈剂量(0.515 mg／L)和无作用剂量(0.0515 mg╱L)。综合以上系列实验，得同以下结论：可以排除细菌、寄生虫、真菌感染的可能；病毒可能是导致暴发病发生的病原，但还需进一步的确诊；确定重金属尤其是Hg是鲟鱼苗暴发性疾病的一个重要因素。更多还原

【Abstract】 Disease outbreaks among cultured sturgeon yearlings have brought great loss to sturgeon husbandry. The thesis presented here is aim to find out the cause of the disease. After investigation we knew the morbidity and mortality, presenting signs, progression of disease and then carried out the study on the disease. The results are below. The primarily examination didn’t find out any bacteria and parasites. Sturgeon juveniles were experimentally challenged with the tissue extract from disease sturgeons. But there are no lethal disease in the result. No suspected virus or fungi was found in liver, speen, kidney and brain by tissue pathogen microbial determination. We also found that prevent and therapy with antibacterial and antiviral have no obviously effect. But the health sturgeons were infected after 9 days when they were placed with disease sturgeon. In the experiment, which healh sturgeons were only given with artifical feed or was starved, we found the starvation caused by refusing the feed maybe evoke or accelerate the disease. We concluded the heavy metal which was traced to water worms, was attributed to the disease after detecting the content of heavy metal in cultivation water, water worms and disease sturgeons tissues. The content of Hg, Pb and Cd especially Hg is very high. Exposure of Amur Sturgeon (Acipenser schrencii Brandt) to Hg for acute and chronic toxic experiment showed that the median lethal concentrations (LC50, 96h) of sturgeon is 0.50145 mg/L, and threshold dosage is about 0.515 mg/L, Inefficiency dosage is 0.0515 mg/L in the long-term exposure. In the chronic toxic experiment, we also found some diseased fish show partially similar sign to the disease outbreak. From all the experiment, we can conclude that some unknown virus agent may be the cause of the disease, and heavy metal poisoning is an important factor to the disease , and the pathogenesis can exclude bacteria, parasites, fungi. Further study on the virus opportunit need to be done.更多还原