Fish can detect the stimulatory proline in squid, lactic acid and adenosine in various fish deals and the ocean mackerel herring meal for example. They can easily sense the lysine in krill and tiger nuts, tryptophan in oyster, crab and clams, methionine in oyster, methionine in krill and crab, the vitamins, minerals, fatty acids and fish ingredients falling in the later stages of breaking down in water. Proper digested fish meal and liver are both very high in arginine which is one of the best gustatory feeding stimulants for many fish, including carp and many catfish species. Fish meals in general are especially high in leucine, glycine, proline, aspartic acid and glutamic acid among others. In terms carp based on the true feeding triggers crab contains.