Identification of feeding stimulants for red sea bream in the extract of marine worm Perinereis brevicirrus.

The marine worm Perinereis brevicirrus is highly evaluated as a fishing bait. In order to identify the feeding stimulant for fish in this worm, various kinds of synthetic extracts simulating the composition of the worm extract were prepared and the responses of red sea bream to them were examined. The complete synthetic extract containing all 6 groups of components (amino acids, guanidino compounds, organic bases, nucleotides, organic acids, and sugars) evoked very active feeding behavior in the fish. When amino acids were omitted from the complete synthetic extract, the activity decreased remarkably. However, the synthetic extracts lacking any one of the other 5 groups still exhibited very strong containing one of the 6 groups, only the extract containing. Although the extract containing guanidine compounds showed a weak activity, glycocyamine and creatine were inactive when tested individually.