Utilization of Chlorella and Daphnia as natural food sources and their combination as a feed supplement compared to commercial feed for common carp (Cyprinus carpio)

This study was carried out to evaluate the effect of adding the two natural food sources, phytoplankton Chlorella spp., zooplankton Daphnia spp. and their combination as a feed supplement and compared them to commercial feed for common carp (Cyprinus carpio L.) fingerlings with different levels. The study was performed in fish laboratory of Animal Sciences Department/ College of Agricultural Sciences/ University of Sulaimani in Iraq, for 12 weeks. The size of fish were varying and the weight ranged between (25.07-37.21 g) with mean initial weight (28.58 g). The fish were acclimated to laboratory conditions and fed with control pellets ( 28.06 % protein) prior to the feeding trials for 21 days, to test the effect of two different levels of the Chlorella spp., zooplankton Daphnia spp. alone and in combination on growth performance, feed utilization, blood parameters, biological parameters, chemical composition and organoleptic (sensory) evaluation of fingerlings. The control treatment (T1) fish were fed a commercial diet without adding any amount of Chlorella and Daphnia , while in other six treatments fish fed control diet with adding Chlorella spp. powder and freeze-dried Daphnia spp. as following: (T2) with 25 g Chlorella/ kg diet, (T3) with 50 g Chlorella/ kg diet, while, in (T4) with 25 g Daphnia/ kg diet, (T5) with 50 g Daphnia/ kg diet, (T6) with 25 g Chlorella + 25 g Daphnia/ kg diet and ( T7) with 50 g Chlorella + 50 g Daphnia/ kg diet. Each treatment had three replicates in which six fingerlings common carp were stocked in each 100 L tank which feed the experimental diets twice daily. The results showed that both Chlorella spp., Daphnia spp. and their combination were very suitable feed supplements for common carp