The White Spot Syndrome Virus has already posed a serious threat to industrial shrimp culture for many years. We studied this disease in Penaeus vannamei. A total of 100 specimens was used to evaluate tissue tropism for WSSV. In case of infectious correlations among the tissues, Kendall’s tau-b test showed that there were significant differences () among the target tissues. The rates of frequency for infected target tissues, which should be calculated between 0 and 1, were 0.71, 0.58, 0.61 and 0.12, respectively, for haemolymph, hindgut epithelial cells, cephalothoracic epidermis, and interstitial tissue of the hepatopancreas. Results indicated that 88% of the gills, 98% of the muscles, 97% of haematopoietic nodules and 97% of the hearts were not severely infected, but these rather showed relatively mild infections. It can be suggested that epithelial cells of the gills prevent replication of the virus in the early stage of WSSV infection, whereas meanwhile epithelial cells of the cephalothorax and those of the hindgut, in contrast, boost the replication of WSSV. Additionally, morphological haemocytic evaluation can be applied as an appropriate infectious indicator in the early stage of WSSV disease in farmed P. vannamei.
Effectiveness of Natural Herbal Oil Formulation against White Spot Syndrome Virus in Penaeus vannamei
