福建省连江县养殖对虾病毒性疾病的调查研究

AN INVESTIGATION ON A DESTRUCTIVE DISEASE IN CULTURED PENAEID IN LIANJIANG COUNTY OF FUJIAN

对福建省连江县养殖对虾的虾病流行情况和发病规律及流行过程中水环境化学、浮游植物、微生物等的动态变化进行了调查，研究了对虾疾病的传染性、传播途径，以及病原与各因子的相互关系。结果表明：不同的对虾种类发病症状基本一致，典型症状为甲壳白斑，甲壳下水肿。该疾病的流行过程可分为三个阶段：发病前期（１－７ｄ）；发病中期（持续时间约１０—１５ｄ）；发病晚期（对虾暴发性死亡时间仅为２—５ｄ）。该流行病是杆状病毒引起并发细菌性传染病，可借海水和病虾尸体为媒介，通过消化道和体表面在不同种虾体间迅速传播。

During an epizootic of a destructive disease in cultured Penaeid in Lianjiang County of Fujian in 1993, the epizootic and infectivity of this disease in some culture ponds were investigated. The investigative results showed that every variety of affected cultured shrimp in Lianjiang County have the same behavioural signs. The cuticle of shrimp had white mottled appearance and there was a liquid swelling below the cuticle of shrimp.The infective course of shrimp in a culture pond can be divided into three stages, which are early stage (1-7d ), medium stage (10-15d), late stage (2-5d). A large amount of bacteria were isolated from the hepatopancreas and muscle of the affected shrimp. Artificial affecting tests demonstrated that the dead bodies of affected shrimp and sea water containing virus were highly infectious. Electron microscopy of the affected tissues of shrimp showed the presence of virus like particles with bar-morphology. These results revealed that the destructive disease of cul'tured shrimp in Lianjiang County was a bar virus disease with bacteria of secondary infection.