Epidemiology And Prevention Of Exopalamon Carincauda Infected With White Spot Syndrome Virus Within Jiangsu

White spot syndrome virus has been highly pathogenic for Penaeus chinensis, Penaeus monodon and Penaeus vannamei, it have caused serious losses in the global shrimp aquaculture industry since 1990's. In recent years, an outbreak of shrimp disease happened frequently in coastal areas of Jiangsu, it caused mass mortality of Exopalamon carincauda.In this paper, we started with the epidemiology, cytopathology, variable region of Exopalamon carincauda in Jiangsu. The WSSV virions were observed in the disease shrimps, they were related with the outbreak of shrimp disease in coastal areas, despite no apparent white spots were found. Through artificial infection experiment, we could confirm that the WSSV was the pathogen of cultured Exopalamon carincauda in Jiangsu.A nested PCR has been used for investigating the WSSV from cultured shrimp and the environmental samples from 21 sites in the coastal areas of Jiangsu during 2010-2011, revealed the presence of WSSV. The result showed that 80% of the cultured ponds were infected with WSSV, and there were massive mortalities in some pathogenetic pond. The incidence of Exopalamon carincauda in Dafeng City was much higher than the others, the mortality increased from the serious areas to adjacent areas, and incidence and mortality in September and October were significantly higher than the other months in the research. The positive rate of crab in mixotrophic culture was high. The biological samples caught from sea water could also be detected WSSV. Observed the ultrastructure of Exopalamon carincauda infected with WSSV by electron microscopy, significant lesions were found:A sign of virus infection was enlargement of nuclei, chromatin condensation and margination, of rough endoplasmic reticulum dilated, the cristae in mitochondria were disintegrated partially, and the number of lysosomes was increased. The cells seriously infected with WSSV were damaged, nuclear fragmentation, the virions released into cytoplasm. Electron microscopic examination revealed the presence of double-envelop, non-occluded, rod-shaped virions, which were similar with WSSV, but there were no statistically significant tail-like structure, only mastoid protuberance.According to the genome of variable region of WSSV, the specific primers were designed to amplify DF1 isolated from Jiangsu. The result was compared with the other isolates, variable region sequences were significantly different, evolutionary relationship between DF1 isolate and Taiwan isolate was closer than the others. DF1 isolate is relative independent evolution with the other isolates from a common ancestor by deletion/insertion polymerphism of the genome.Through investigating the growth characteristic of Exopalamon carincauda and the culture condition of environment within Jiangsu, with considering the various factors, we propose a series of prevention and control measures to prevent the Exopalamon carincauda WSSV large-scale outbreak in Jiangsu.