Effects of temperature on hematological and histopathological changes and survival rate of juvenile Fenneropenaeus vannamei experimentally challenged to White Spot Virus

Many shrimp farmers were suffering from White Spot Disease (WSD) onset in last decades. Oscillation of environmental factors could lead mortality in susceptible hosts. Our study was aimed to investigate the effect of different temperatures on juvenile Fenneropenaeus vannamei experimentally exposed to White Spot Virus (WSV). Five hundred and forty juveniles were distributed among ۳ treatments in triplicates, ۲۲, ۲۵ and ۳۰°C and experimentally WSV were injected in the shrimps. Our results showed mortality started at ۳۶ h post inoculation (hpi) in the treatment at ۲۵°C (T۲۵), meanwhile the mean value of mortality percent at ۵۴ hpi in T۲۵ (۷۱.۱۰±۱۷.۳۵) showed the significant difference (p=.۰۴۵) with T۲۲ (۳.۳۳±۳.۳۳) and T۳۰ (Not Observed, NO.). Our results suggest that in site selection, in primary stage of farm designing, water temperature at more than ۲۹°C, should be considered as key environmental factor. This finding can lead us that why the White Spot Disease occurred with high mortality in some area when the days of shrimp culture were prolonged until mid autumn.

Keywords:

White Spot Syndrom Virus , Temperature , Fenneropenaeus vannamei , Challenge