Freshwater green algae Chlorella sp. and Scenedesmus obliquus enriched with B group of vitamins can enhance fecundity of Daphnia magna

One of the most important aims of aquatic hatcheries is availability to mass produce of Daphnia magna as a live food with high nutritional value in the shortest time. In the present study, D. magna fed with two freshwater green algae species, Chlorella sp. and Scenedesmus obliquus, enriched with different dosages of a mixture B group vitamins (0, 0.5, 1 and 2 ml.l) were compared at two stages (at the beginning of the culture and at the end of logarithmic growth phase). The results showed that increases in the B group vitamin levels in both enriched algae performed, increasing the fecundity and population growth rate in D. magna at the two compared stages, but significantly only with the control group (P<0.05). The highest fecundity and population growth rate obtained in D. magna was when they were fed algae enriched with 2 ml.l , but not significantly with 0.5 and 1 ml.l (P>0.05).