A parvo-like virus in cultured redclaw crayfishCherax quadricarinatus from Queensland, Australia

Diseases of Aquatic Organisms

Elizabeth C. Kulpa¹  Howard Prior¹  Andrew Fisk¹  Max Wingfield¹  Kelly M. L. Condon¹  Rachel O. Bowater¹  Angela Reid¹ 

关键词: Cherax quadricarinatus;    Virus;    Parvo-like virus;    Disease;    Aquaculture;    Crayfish;    Pathology;   

DOI  :  10.3354/dao050079

学科分类：生物科学（综合）

来源: Inter-Research

【 摘 要 】

ABSTRACT: In the summer of 1999/2000, an epizootic occurred in cultured juvenile redclaw crayfish Cherax quadricarinatus on one commercial crayfish farm in northern Queensland, Australia. Mortalities occurred over 4 wk, with up to 96% cumulativemortalities in 2 earthen ponds stocked with juveniles. The crayfish were weak, anorexic and lethargic. A transmission trial was conducted, using filtered, cell-free extract prepared from infected crayfish as inoculum. The disease was reproduced, withon-going mortalities occurring in inoculated crayfish over 55 d. Experimentally inoculated crayfish showed gross signs of malaise, anorexia and disorientation before dying. Two types of intra-nuclear inclusion bodies (INIBs) were seen in tissues ofendodermal, ectodermal and mesodermal origin by light microscopy with haematoxylin and eosin (H&E) stained sections. ŒEarly¹-stage INIBs were eosinophilic, rounded and located centrally within slightly enlarged nuclei while Œlate¹-stage INIBs werewell-rounded and deeply basophilic. The gills, cuticular epithelium and epithelial cells of the foregut, midgut and hindgut were the most heavily infected tissues. By transmission electron microscopy, virions with an average diameter of 19.5 nm were seenwithin electron-dense granular inclusion bodies within enlarged nuclei of both naturally and experimentally infected crayfish. The size of the virions and cytopathology are consistent with characteristics of viruses in the Family Parvoviridae. Thisis the first reported case of mass mortality caused by a parvo-like virus infection in C. quadricarinatus.

【 授权许可】

Unknown