Common carp from Europe have a different main diet - omnivores variety of living and dead stuff. Grass carp (GC) are herbivores and they might not have a "mud vein" aka red meat between fillet and skin. I have never cleaned a GC. Numerous fish such as tilapia and Lake Erie walleye have red meat between the fillet and skin. Red meat allows lactic acid build up for strength endurance. GC have white relatively firm meat - large flakes. However they do have extra bones compared to BG,LMB and CC. Some pond owners I know that have eaten the large ones compared the taste to walleye. Maybe? It is a matter of opinion. If you eat a GC report back with your opinions.