Bioaccumulation of copper in post-larvae and juveniles of freshwater prawn Macrobrachium rosenbergii (de Man) exposed to sub-lethal levels of copper sulfate

The culture of giant freshwater prawn Macrobrachium rosenbergii (de Man) is fast expanding in Asia including India. Copper sulfate is extensively used in freshwater prawn culture ponds to control diseases and filamentous algae. In the present investigation, bioaccumulation of copper was studied in post-larvae (10 ± 1 mm; 0.008 ± 0.002 g) and juvenile (58 ± 5 mm; 1.25 ± 0.28 g) M. rosenbergii. The post-larvae and juveniles were exposed to three sub-lethal levels (0.001, 0.01, 0.1 of the 96 h LC50 value; i.e., 0.0652, 0.652, 6.52 μg l− 1 for post-larvae, 0.39, 3.9 and 39.0 μg l− 1 for juveniles) for a period of 30 and 60 days, respectively. Copper accumulation was analyzed in post-larvae (whole animal) and gill, hepatopancreas and muscle tissue of juveniles. Results revealed that accumulation of copper in both post-larvae and juveniles increased with increasing test concentration (p < 0.05). Among tissues, hepatopancreas accumulated maximum levels of copper followed by gills; while muscle tissue accumulated less copper. There were significant differences (p < 0.05) in accumulation of copper in various tissues among treatments. In the case of post-larvae, significant differences (p < 0.05) in accumulation of copper were observed in the 6.52 μg l− 1 treatment. Prawn muscle tissue accumulating copper is important from the point of human food safety as constant exposure to sub-lethal levels of copper for 6–8 months (culture period) may result in accumulation of higher levels of copper in muscle tissue.