Polychaetes as potential risks for shrimp Pathogen transmission

Polychaetes comprise the benthic meiofauna of the soft-bottom intertidal zone and of shrimp ponds in coastal areas. While polychaetes provide benefits to the shrimp farming industry as (i) natural food in traditional shrimp ponds, (ii) nutrient regenerators through bioturbation and removal of organic waste in the sediment through feeding, and (iii) feed supplement to enhance maturation of shrimp brooders, the conditions present in aquaculture ponds may increase the opportunity for polychaetes to transfer pathogens to shrimp through the food chainThere is growing concern that internationally traded polychaetes, which are fed to shrimp brooders, are potential vectors for the transmission of other shrimp pathogens. The detection of the aetiological agents of two newly emerging diseases of shrimp in polychaetes, Enterocytozoon hepatopenaei (EHP) and Vibrio parahaemolyticus_AHPND causing hepatopancreatic microsporidiosis (HPM) and acute hepatopancreatic necrosis disease (AHPND), respectively, suggests that these worms can be a host or/and passive carrier of these pathogens. This review discusses the benefits of polychaetes to shrimp farming, the risk of shrimp pathogen transmission by polychaetes at the pond, hatchery and global level, and calls for closer observation on shrimp pathogens in polychaetes used as shrimp feed.