December 1998
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63 Reads
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33 Citations
Journal of Shellfish Research
Since first observed in the summer of 1993, a serious pustule disease has spread among several abalone hatcheries in the Dalian area. It affects different growth stages of the abalone. Mortality has been as high as 50-60%. Three strains of bacteria (D, T, and N) were obtained, isolated, and purified from the Aquacultural Company of Dalian (D), the Aquacultural Company of Precious Sea Food of the Pacific Ocean (T), and the Dalian New Harbor Aquacultural Company (N). Observation by electron microscopy showed that the three strains were all short rod bacteria with a single polar flagellum. They all grew in 1% tryptone water in the ranges, 15-42°C; salinity, 0-70‰; and pH, 5.5-11. Physiological and biochemical analyses gave the same result as in an earlier study by the authors. The bacteriophage of the D strain, which was isolated by the authors (reported elsewhere) could propagate and replicate on the N and T strains. Thus, the three strains are concluded to belong to the same species of bacteria, one earlier identified as Vibrio fluvialis-II. Results of experimental trials indicated that the pustule disease is transmitted through lesions in the foot. Infection quickly followed intramuscular injection. Infection did not result when bacteria were included in the food or when present in the surrounding seawater.