본 연구는 북방전복 (H. discus hannai) 의 겨울철 저수온으로 발생하는 폐사원인 규명을 위한 생리학적인 반응을 조사하기 위하여 수온 $12^{circ}C$를 대조구로 $7^{circ}C$ 및 $4^{circ}C$의 실험구를 설정하고 10일간에 걸쳐 생존율, 항산화효소의 활성 및 총 단백질 농도를 측정하였다. 그 결과 $7^{circ}C$ 저수온 실험구에서는 SOD 활성 및 총 단백질 농도가 대조구와 차이를 나타내지 않았으며 생존율은 90.8%를 나타내었다. 반면에 $4^{circ}C$ 저수온 실험구에서는 SOD 활성은 노출직후에 급격히 상승하여 12시간째까지 대조구보다 유의적으로 높게 나타났다. 또한 총 단백질 농도에 있어서는 24시간째부터 실험종료 시까지 대조구보다 유의적으로 높게 나타났으며, 생존율은 3일째 10마리의 폐사를 시작으로 10일째 전 개체가 페사하였다. 이상의 결과로 북방전복 (H. discus hannai) 은 $7^{circ}C$의 저수온 실험구에서는 다양한 생리적 기작을 이용하여 생존이 가능한 반면에 $4^{circ}C$의 저수온 실험구에서는 생리적 순응반응을 나타내고 있으나 방어기작의 한계를 벗어나 생존이 불가능하다고 추정된다.
This study was performed to obtain the basic data on physiological responses of low water temperature stress of the cultured Pacific abalone, Haliotis discus hannai. Abalones were exposed at low water temperatures of $7^{circ}C$ and $4^{circ}C$. We have investigated survival rate, superoxide dismutase (SOD) activity and total protein (TP) in the abalone by the exposure times (0, 3, 6, 12, 24, 72, 120, 168 and 216 hours). Survival rate of the abalone at $7^{circ}C$ experiment was 90.8%, whereas at $4^{circ}C$ experiment was 0% after exposure 10 days. SOD activity was significantly increased until 12 hours after exposure to $4^{circ}C$, and then was recovered to starting level after 24 hours. However, there was no significant difference between control ($12^{circ}C$) and $7^{circ}C$ experiments. TP was significantly increased until 216 hours after 24 hours at $4^{circ}C$ experiment, but $7^{circ}C$ experiment showed no significant differences compared to control ($12^{circ}C$) experiment. Therefore, H. discus hannai was acclimated in low water temperature stress at $7^{circ}C$, but at $4^{circ}C$, all abalone died possibly because they exceed the limits of defense ability to too low temperature.
