FISHERIES RESEARCH INSTITUTE,MOA,TAIWAN

A measurement of labile copper was conducted by differential pulse anodic stripping voltammetry (DPASV). The bear prawn, Penaeus semisulcatus, larvae were raised at different water temperature (27±1℃, 30±1℃, 33±1℃ and 36±1℃). The copper complexing capacity in the tank water was measured from the sixth to the tenth day, after larvae were stocked. The result showed that the water in the 33℃ treatment almost had the highest copper complexing capacity (1.3-15.9 μg/l) after the mysis stage. The survival rate (84%) of prawn larvae was the highest in the 30℃ treatment. Before the mysis stage, the copper complexing capacity (27.5 μg/l) in the 30℃ treatment was the highest. However, the copper complexing capacity in the 30℃ treatment water after Mysis stage ranged between 2.8 and 11.9 μg/l. In the 27℃ treatment, the survival rate of the larvae was 77% and the copper complexing capacity of culture water after the mysis stage ranged between 2.8 and 14.9 μg/l. The survival rate of prawn larvae in the 36℃ treatment were the lowest (7%), and the copper complexing capacity of culture water was unstable. Most of the complexes belonged to strong stable nonlabile complexes and weak stable nonlabile complexes.
Key words: Penaeus semisulcatus larvae, Larvae rearing water, Copper, Complexing capacity.