Description

Abstract: A mass mortality of up to 60% per tank occurred in 28-day-old Macrobrachium reosenbergii postlarvae cultured under intensive conditions in a hatchery in Thailand. Grossly affected prawns displayed a diffuse ‘milky’ white body opacity; histologically and ultrastructurally, segmental myofibre (myofibrillar and sarcoplasmic) necrosis unassociated with any infectious agents was observed and diagnosed as idiopathic muscle necrosis. Avoidance of overstocking and increased dissolved oxygen in tank water have proved effective in preventing subsequent recurrence of the condition.