In the Asia-Pacific region, shrimp cultivation is the most lucrative and profitable aquaculture industry, and recent developments in India have threatened the industry's success due to microsporidian parasite, Enterocytozoon hepatopenaei (EHP) associated with retarded growth without other clinical signs, causing significant economic losses to the shrimp industry. In the present study in the nursery Mild EHP was noticed before shifting to the grow-out pond. After shifting to the grow-out pond, very poor growth was noticed in all the ponds, and also heavy size variations were noted. In V5 pond growth was stented due to EHP, and in pond V1 reverse growth was noticed due to size variation. Overall in all ponds, very poor weekly gains of .6 to .9 grams were recorded.  In the present study due to slow growth with size variation Pond V4 shrimp were harvested at 136 counts and Pond V2 was harvested at 120 counts. The remaining ponds harvested 133 and 136 counts. So the present study confirms that sometimes the EHP-infected seeds show negative results PCR lab. But after stocking to nursery or growing out EHP infection can expose the middle of the culture also. So better before shifting the seeds to the grow-out pond to confirm through microscopic analysis as well as PCR lab results as free from EHP.