APPEARANCE OF INFECTIOUS HEMATOPOIETIC NECROSIS VIRUS (IHNV) AND NEUTRALIZING ANTIBODIES IN SOCKEYE-SALMON ONCHORYNCHUS NERKA DURING THEIR MIGRATION AND MATURATION PERIOD

The appearance of infectious hematopoietic necrosis (IHN) virus and th e presence of neutralizing antibodies were determined in a population of adult sockeye Oncorhynchus nerka salmon during their spawning migra tion. Both IHN virus and neutralizing antibodies were detected in sock eye salmon while still in sea water. This is the first reported findin g of the virus in wild salmonids in the marine environment and suggest s the possibility of a marine host or reservoir. The possibility of ve rtical or egg-associated transmission was investigated by crossing adu lts with different titers of IHN virus and also by exposing these game tes to the virus to increase the chances of infecting progeny. Vertica l transmission of IHN virus was not observed in eggs or fry from the c rosses of IHN infected broodfish, even when eggs were water-hardened i n the presence of the virus.