Last week on a dive, we came across a cowrie nestled in a coral. The DM got us to stop and watch while she gently stroked the top of the shell with her finger. Almost immediately, the mantle started to appear, and within a very short time, completely covered the entire shell. Can anybody enlighten me as to what this was a reaction to? From the way the mantle was completely protruding, you'd like to thnk that the it was a pleasurable experience for the cowrie, and not a stressful response.