Effect of algae Padina astraulis Hauck extract on growth indices of common carp (Cyprinus carpio)

The present study was carried out to investigate the effect of Padina astraulis on some growth indices of common carp (Cyprinus carpio). Accordingly, 250 fry carp of common carp with average weight of 20 g were distributed in four treatments including: commercial diet (control), algae with 0.5 % (diet 1), algae with 1 % (treatment 2) and algae with 2% (treatment 3) for 42 days. Fish biometric data were used to study the growth indices at the beginning, the middle and the end of the experiment. Results of data analysis at the end of the period showed that the highest percentage of weight gain and specific growth rate were in type 2 however the lowest one was at control group, but there was no significant difference between treatments (P> 0.05). Also, the highest feed conversion ratio was observed in the control group and the lowest was in treatment 2 but there was no significant difference between treatments (P> 0.05). According to the results, it seems that the use of padina algae with concentrations used in this study could improve the growth indices of common carp, although this improvement was had not significantly different.