Research Article
Hui Shen, Ge Jiang, Xihe Wa
Abstract
In recent years, several pathogens have emerged and caused heavy mortality in Asia. In this study, we investigated the prevalence of pathogens in specimens of whiteleg shrimp (Penaeus vannamei) collected from greenhouse ponds. In total, six pathogens were tested in these shrimp, three of which, including Enterocytozoon hepatopenaei (EHP), acute hepatopancreatic necrosis disease (AHPND)-causing Vibrio parahaemolyticus and infectious hypodermal and haematopoietic necrosis virus (IHHNV), were detected in shrimp aquaculture, with EHP being the most prevalent; Taura syndrome virus (TSV), White spot syndrome virus (WSSV) and yellow head virus (YHV) were not detected in these samples. Ultrastructure examination revealed the presence of a large number of EHP spores infecting hepatopancreatic epithelial cells of shrimp. Body weight (BW), body length (BL) and BW/BL ratio, revealed growth retardation among EHP-infected shrimp, as indicated by the significantly lower values of BW, BL and BW/BL ratio in these shrimps than those in EHP-uninfected shrimp (P<0.05). Together, these data indicated that EHP causes severe growth retardation of shrimp and is a major pathogen of aquacultured shrimp culturing in greenhouse ponds in Jiangsu Province; effective measures should be undertaken to control its spread.