Combined effects of copper and temperature on Hematological constituents in the Rock fish, Sebastes schlegeli

Abstract

Copper (CuSO 4) has been widely used to control algae and pathogens in fish culture ponds. However, its toxic effects on fish depend not only on its concentration in water but also on water quality. The susceptibility of the rockfish, Sebastes schlegeli to copper was evaluated at three water-temperatures (WT; 18, 23 and 28℃) for 4 days. After the exposure of two copper concentrations (100 and 200 μg/L), a hematological effect was exerted on rockfish, by causing changes in red blood cell count and hematocrit value at 28℃. Total protein levels of the fish showed a tendency of coin crease with glucose depend on the WT, after copper exposure. However, the plasma calcium and magnesium levels were significantly increased at 200 μg/L copper, regardless of the WT. Enzymes activities including ALT and LDH in serum were also significantly increased depend upon the copper treatment only. This indicates that inorganic components and enzymes activities were sensitive indexes to stress by toxicant such as copper. The cortisol levels were significantly elevated by both WT rising and copper treatment in serum of rock fish. In conclusion, these changes can be seen as an initial response to temperature stress and as a sustaining response to copper exposure. The present findings suggest that a simultaneous stress by temperature change and copper exposure could accelerate an alteration of hematological and plasma biological parameters in the rockfish. 최근 한국 연근해 수온의 장기변동과 관련한 연 구에서 우리나라 동, 서 및 남해 해역의 표층 수온 의 지속적인 상승이 보고되었다 (Seong et al., 2010). 온도는 생물체의 성장, 번식 및 분포에 영향을 미 치는 중요한 요인으로 작용하며, 특히 어류는 수온 변화에 민감하여 대사, 삼투압 조절 및 면역 등의 생명활동에 큰 영향을 받을 뿐 아니라, 미미한 수 온변화에도 생존의 위협을 받는 것으로 알려져 있 다 (Logue et al., 1995). 국 · 내외 연구에서 수온의 급변이 어체의 생리적 변화 및 스트레스 요인으로 작용하여, 생체 내 대사와 혈액성상의 변화를 보인