Abstract
The amyotrophia of Japanese black abalone Nordotis discus discus, an infectious disease caused by an unknown filterable agent, is the most serious problem in abalone hatcheries in western Japan. In the present study, it was experimentally demonstrated that the disease agent was transmitted through water to susceptible 0-year-old abalones from convalesent 2-year-old carriers which had previously been produced by immersion challenge. The agent was also transmitted via water to juvenile abalones from female adults which were caught in the sea as brood stocks and suspected to be inapparently infected. These results indicate the importance of prevention of horizontal transmission of the amyotrophia agent in abalone hatcheries.
