a comparison of nutritional value and a survey of nutritional and financial proportion of various sizes of silver carp (hypophthalmichthys molitrix) in spring season

silver carp is the major specimen in warm water fish culture system in iran which is presented in various size and different price. the present study was aimed to compare nutritional value and to investigate proportion of nutritional value and financial of various weight groups of silver carp in spring season. for this purpose silver carp was prepared in market sizes and their dry matter, fat, protein and ash content and fillet yield were determined and the indices of proportion of nutritional value and financial (np) and justified price difference based on dry matter content (pddm) were calculate for weight groups. according to obtained results, the more heavy weights of silver carp contain lower moisture but higher fat and energy (p 0.05). light weight group has a higher (p 0.05), except fat (p<0.05). with regarded to these results, light weight has a better nutritional proportion than medium and heavy weights and the light weight is advised fir buying until that the price difference between light weight and two other one be more than calculated pddm indices for them. but when the choosing be between medium and heavy groups, both of them have a nutritional value proportionate with their prices.