Evaluation of the resistance to the acute - hepatopancreatic necrosis disease (AHPND) of Penaeus indicus at stages PL 50-55

Abstract

A recently emerged bacterial disease in shrimp farming is the acute hepatopancreatic necrosis disease (AHPND), also known as early mortality syndrome (EMS), causing a mass mortality in shrimp post larvae in newly stocked ponds. Initial observations show that Indian white prawn (Penaeus indicus) has not been infected with AHPND. However up to date there is no scientific research investigating on the resistance to EMS/AHPND of Penaeus indicus shrimps. Hence, this study was designed to evaluate the susceptibility of Penaeus indicus to AHPND in comparison to using standardized challenge model of Penaeus vannamei. Immersion challenge tests on these two shrimp species were performed with pathogenic strain of Vibrio parahaemolyticus at the concentration of 3 x 106 CFU/ml during the period of 7 days. Statistical analysis revealed that significance in cumulative mortality rate between group treatment differences was not detected (P>0.05). However, lower cumulative mortality rate in Penaeus indicus was recorded continuously during experimental period compared to Penaeus vannamei. Based on the results, it can thus be suggested that Penaeus indicus has higher resistant ability to AHPND than Penaeus vannamei in comparison of cumulative mortality rate after challenged with pathogenic strain of Vibrio parahaemolyticus. This finding confirmed the reliability and capacity of Penaeus indicus as a good alternative species for shrimp farming to reduce adverse impacts of AHPND. Key words: Penaeus indicus Penaeus vannamei Acute Hepatopancreatic Necrosis Disease (AHPND) Vibrio parahaemolyticus Resistant ability