江苏启东文蛤大面积死亡原因调查

The Cause of Massive Mortality of Clam Meretrix meretrix Linnaeus in Qidong City,Jiangsu Province

采集启东文蛤发病地区的养殖海水样品进行水质分析，并对感染文蛤做了细菌分离和电子显微镜超薄切片。结果表明，此次文蛤大面积死亡非化学污染和细菌感染所致；发病文蛤外套膜电镜超薄切片中发现了病毒包涵体和散在病毒颗粒，病毒颗粒呈球形，直径约60～80nm。无囊膜。其他感染组织也有明显的病理变化，如核固缩、线粒体溶解、微绒毛脱落、细胞器空泡化。

Seawater samples were collected from the area where the high mortality of clam Meretrix meretrix occurred in Qidong city, Jiangsu province, and the tissues and organs in the infected clam such as mantle, branchia, foot and digestive deverticula were analyzed by chemical method, bacteria isolation and ultrathin sections. The results indicated that the chemical pollution and bacteria were not the cause of the high mortality; the ultrathin sections observed with transmission electron microscope showed that there were some inclusion bodies with viruses and other dispersed viruses in the mantle. These spherical viruses with the sizes of 60-80 nm in diameter and lack of capsula. Also, severe cytopathological changes including condensing of nuclei, dissolving of mitochondria,desquarnation of microvilli and vesicling of other organells were observed obviously in other infected tissues.