1Fukui Prefectural Inlandwater General Center, Fukui, Fukui 910-0816, 2Ocean Research Institute, University of Tokyo, Nakano, Tokyo 164-8639, Japan
In this study, we reared 0+- and 1+-year-old four-spine sculpin, Cottus kazika, in artificial seawater (SW), 1/3 SW and freshwater (FW) and the survival rate and growth were compared. When 0+ fish were reared in SW and FW, the survival rate of the SW group decreased to approximately 60% within the first 50 days, then became stable thereafter. The survival rate of the FW group gradually decreased to almost the same level after 110 days while 0+ fish reared in 1/3 SW revealed a higher survival rate than those in SW. The survival rates of 1+ fish reared in SW and FW were not different. The growth was greater in SW-reared fish than in FW-reared ones in both 0+ and 1+ fish. The growth of 0+ fish reared in SW and that of those reared in 1/3 SW were not different. These results suggest that rearing in SW or diluted SW would increase the efficiency of culture in this species.