Chemoreception and feeding responses of red king crabs to potential bait extracts

Abstract

Laboratory experiments were conducted to study the chemosensation and feeding behavior of red king crab (Paralithodes cαmtschαticus). Five extracts of squid, herring, mussel king crab muscle, and king crab ovary were used as test solutions. Change in antennular flicking rate was employed as an index of detecting chemicals. The median effective concentration at which 50% of crabs detected the solution varied between 10-4 to 10-3 g l-1 for the five extracts. Crabs were most sensitive to conspecifc muscle, but least to mussel. Movement of maxillipeds, probing of chelipeds, movement ofwalkinglegs, and body elevation indicated the onset of feeding behavior. Among these indicators, movement of maxillipeds was the most sensitive. The median effective concentration at which 50% of crabs showed feeding responses ranged from 10-2 for ovary to 10-3 g l-1 for herring extract. Herring was the most effective natural bait for red king crabs, while little difference was detected between the sexes for chemosensation.