Abstract
Acquired resistance to erythrocytic inclusion body syndrome (EIBS) was investigated in coho salmon (Oncorhynchus kisutch).
Fish which were experimentally infected with EIBS and maintained at 15°C for 242 days were challenged by EIBS virus and kept at 8°C. The fish survived the challenge, though they showed a slight decrease in Ht values which recovered presently. This result indicates that acquired resistance to EISB continues at least as 242 days. Follow-up examination of coho salmon which survived EIBS in freshwater farm ponds revealed that they maintained acquired resistance after being transferred to marine farms.
