In the present study was conducted to examine the effects and interactions of dietary vitamin C levels on the growth performance, antioxidant ability, muscle composition and enzyme activity in freshwater prawn Macrobrachium malcolmsonii (M. malcolmsonii). Additional, the vitamins C was dietary supplemented for freshwater prawn M. malcolmsonii. The experimental basal diets were supplemented with M. malcolmsonii at the rates of 0 (control), 25, 50, 100, 200 and 400mg/kg dry feed weight. The as-supplemented vitamin C was fed in M. malcolmsonii for a period of 90 days. In the present investigation revealed that prawns fed with diet supplemented with 25–100mg/kg of vitamins C shows enhanced (P0.05) in feed conversion ratio (FCR) were observed in prawn fed different diets. Addition, prawns fed with 25–100mg/kg of vitamins C supplemented diets achieved significant (P0.05) alterations in prawns fed with 25–100mg/kg of vitamin C supplemented diets. Therefore, the present study proposed that 100mg/kg of vitamin C could be supplemented for flexible enhanced survival; growth, antioxidant defense system and production of M. malcolmsonii

In this study, we assessed the suitable level of replacement of fishmeal with a blue green microalga, Arthrospira platensis in feed for the post larvae (PL) of the freshwater prawn, Macrobrachium rosenbergii by evaluating the growth performance, prawn proximate composition, feed utilization parameters and the activity of digestive enzymes. The prawns were fed 5 different diets: a control diet and 4 different diets containing A. platensis at various levels such as 25%, 50%, 75%, 100%. These diets were fed to the PL for 90 days in triplicates. The growth performance in terms of weight gain, specific growth rate and feed efficiency ratio were found significantly (P25>75>100% replacement of fishmeal with A. platensis. These results concluded that a partial replacement of the fishmeal with A. platensis at the level of 50% is beneficial for the growth of prawn M. rosenbergii