Which is a better chelating agent in beluga, Huso huso (L.), coriander, Coriandrum sativum, or active charcoal?

To compare the chelating effect of coriander, Coriandrum sativum, and active charcoal on beluga, Huso huso, a total of 270 beluga (260±2 g) were initially fed with a diet containing 0, 5, 10, 15 and 20 g of coriander and charcoal per kg of diet for 60 days. The fish were then subjected to 1 mg/L of heavy metals (lead, cadmium, and copper) for seven days. The best growth and feeding performances before and after challenging with heavy metals were observed in fish fed with 15 g/kg active charcoal. Also, the best growth performance before challenging with heavy metals was observed in fish fed with 5 and 10 g/kg coriander followed by fish fed with 10 and 15 g/kg coriander after the challenging stage. The growth and nutritional efficiency were better in coriander than the charcoal treatments, especially in the pre-challenge stage. No mortalities were observed in charcoal treatments at all. While mortality occurred only in fish fed with 20 g/kg coriander in the first stage, a 100% survival rate was observed only in the second stage of fish fed with 10 g/kg coriander. In both stages of the experiment, the highest percentages of carcass protein and lipid were obtained in fish fed with 10 g/kg coriander and 15 g/kg of charcoal. Also, the lowest ash and the highest moisture were related to the control group. The amounts of protein and ash were higher in carbon treatments while the amounts of lipid and moisture were higher in coriander treatments. Minimum amounts of cadmium, copper, and lead were obtained in fish fed with 15 and 20 g/kg charcoal and coriander. The concentration of the heavy metals was significantly lower in fish fed with carbon (P<0.05). Therefore, 5-10 g/kg coriander is a better additive in low heavy metal concentration. But in an environment with a higher concentration of heavy metals, adding 15 g/kg active charcoal to beluga diet is recommended.