effect of adding microalgae chlorella sp. on some biological parameters and proximate analysis of common carp cyprinus carpio l.

Background: chlorella is commonly used as a dietary supplement. various studies and researches have been done regarding the intervention of microalgae as foods for a long time. and, it is found that chlorella have potential health benefits, in terms of their protein and antioxidant content. thus, with the objective of formulating nutritional supplements, this algae is being harvested in artificial ponds on a large scale and could be used in different ways such as feed supplement or a replacement with a source of protein. objectives: evaluate the effect of feed containing various ratios of chlorella on some biological parameters in common carp. methods: the experiment was conducted for 105 days and for this purpose 200 common carp fingerlings (c. carpio l.) were brought from a local fish aquarium in iraq. mean initial weight was 35.7g. the fish were acclimated to laboratory conditions and fed with control pellets (29% protein) prior to the feeding trials for 21 days in fish laboratory/dept. of animal sciences/ college of agricultural sciences/university of sulaimani. in t1 fish were fed a diet with 0 chlorella gm/kg ,while in t2, fish were fed a diet with 2.5 chlorella gm/kg, t3 represents the third treatment, in which fish were fed a diet with 5 chlorella gm/kg, and in t4 fish were fed a diet with 7.5 chlorella gm/kg. results: the present study clearly showed that feeding algae as a feed additive to fish remarkably changed the studied biological parameters, in hepatosomatic index all treatments were significantly different from the control, spleenosomatic index of the control and t4 were significantly higher than others, in gonadosomatic index the t2 and t4 significantly differed, while t4 was significantly higher than other treatments in kidneysomatic index. fish weight without viscera and weight without viscera & head differ significantly among treatments with the addition of chlorella the diet. conclusions: chlorella can be used as protein rich sources to replace fishmeal or as feeding additives in the diets of common carp fingerlings with different levels. chlorella products are safe and of good quality.