Growth and Spawning of Crassostrea rivularis from the Southern Sea Korea

한국 남해안산 강굴, Crassostrea rivularis의 성장과 산란

Growth and spawning of Crassostrea rivularis inhabited in estuary of Gahwacheon, Sacheon, Gyeongsangnam-do, Korea were investigated from June 1995 to August 1996. The shell height of two-year oyster ranged from 56.7 ${\pm}$ 4.8 mm in October to 87.7 ${\pm}$ 24.6 mm in June, and that of three-year oyster was from 123.0 ${\pm}$ 24.7 mm to 133.2 ${\pm}$ 10.5 mm. Condition factor was in a range from 0.0409 ${\pm}$ 0.0138 (October) to 0.0732 ${\pm}$ 0.0267 (July), and it began to increase in December. It reached the maximum in July, then decreased rapidly thereafter. The spawning period was determined to be July and August on the basis of monthly changes in condition factor and relative growth of meat weight to shell weight.

사천의 가화천에 서식하는 강굴, Crassostrea rivularis 의 성장과 산란기가 조사되었다. 2년생 강굴의 각고는 10월에 56.7 ${\pm}$ 4.8 mm에서 이듬해 6월에 87.7 ${\pm}$ 24.6 mm 범위였으며, 3년생은 123.0 ${\pm}$ 24.7 mm 에서 133.2 ${\pm}$ 10.5 mm 크기였다. 비만도는 0.0409 ${\pm}$ 0.0138 (10월) 에서 0.0732 ${\pm}$ 0.0267 (7월) 범위로, 12월에 증가하기 시작하여 7월에 최고값을 보였으며 그 후 빠르게 감소하였다. 비만도와 각중에 대한 육중의 상대성장을 바탕으로 강굴의 산란기는 7, 8월로 판명되었다.