Evaluation of resistance to acute hepatppancreatic necrosis disease (AHPND) of banana shrimp penaeus merguiensis postlarvae at stages of PL40-50 and PL100-110

Abstract

Acute hepatopancreatic necrosis disease (AHPND), a recently emergent disease in penaeid shrimp, is caused by specific strains of Vibrio parahaemolyticus (VPAHPND) that harbor an additional plasmid encoding a virulent toxin. Owing to its adverse impact on the global shrimp aquaculture industry, assessment of disease resistance of commonly cultivated shrimp has been of great importance. This study is a preliminary report on possible resistance of banana shrimp Penaeus merguiensis against AHPND. Immersion challenge tests were conducted for seven days on P. merguiensis at two postlarval stages with Penaeus vannamei as the reference model. The challenge doses were 106 CFU/mL and 3x106 CFU/mL for PL40-50 and PL100-110, respectively. By comparing cumulative percentage mortalities, results showed that P. merguiensis at the earlier stage (66.9 ± 19.69%) was as vulnerable as P. vannamei (63.4 ± 18.80%) (P>0.05), whereas PL100-110 was able to resist AHPND to a certain degree (P. merguiensis: 51.2 ± 21.39%, P. vannamei: 96.4 ± 5.98%; P<0.001). These pointed out that the resistant ability of P. merguiensis might be improved when growing up, suggesting future in-depth research so that the selective breeding and culturing programs of this species would be implemented for the sustainability of shrimp farming in Vietnam and in other Asian Pacific nations. Keywords: Acute hepatopancreatic necrosis disease (AHPND), Vibrio parahaemolyticus, Penaeus merguiensis, shrimp postlarvae, immersion challenge, disease resistance