|Studies on the oyster diseases. 1. Pathogenetic investigation|
Chun, S.K. (1970). Studies on the oyster diseases. 1. Pathogenetic investigation. J. Korean Fish. Soc. 3(1): 7
In: Hangug susan haghoi ji = Journal of the Korean Fisheries Society. Hangug susan haghoi: Busan. ISSN 0374-8111, more
The present paper deals with mortality and pathogenetic investigation of the oysters Crassostrea gigas cultured by the conventional bamboo and hanging method in Kimhae and Koje-Do in 1969. The results of the investigation may be summarized as follows: 1. Mortality of the oysters by the bamboo method in Kimhae was 9.5% in June, 10.2% in July, 12.3% in August and 12.1% in September, respectively. 2. Mortality of the oysters cultured by the hanging method in Koje-Do was 2.4% in June, 2.9% in July, 30.7% in October, 37.3% in November and 30.0% in December, respectively. 3. The diseased oysters had severe inflammation, necrosis and multiple abscess in the epithelia of stomach, mid-gut, digestive tubules, blood vessels and gonads, mucous membrane and surrounding tissue. 4. From August gram negative bacteria were found in the nodules of connective tissue and multiple abscess of the diseased oysters. Particularly the connective tissue of the diseased oysters contained more bacteria than epithelia. 5. Since the bacteria are less abundant in the region of digenerated tissue, mortality of the oysters is not caused only by the infectious bacteria but seems that is also caused by other environmental factors such as extreme temperatures and salinities.