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Hole drilling in crab and gastropod shells by Eledone cirrhosa (Lamarck, 1798)
N.W. Runham, C.J. Bailey, M. Carr, C.A. Evans and S. Malham

Eledone cirrhosa readily feeds on crabs (e.g. Carcinus maenas) and gastropods (e.g. Nucella lapillus and Littorina littorea) in the laboratory. Penetration of the shells of these prey can be readily followed, with little or no disturbance, by suspending a microphone in the water and recording the sounds. The characteristic sound consists of a series of short bursts, resembling the noise of rasping, separated by quieter periods. A bore hole is formed through the shell of the prey with a morphology typical of the type of shell. In the gastropod this is located in a small area near the top of the shell, while in the crab nearly 60% were located in the carapace with 80% of these occuring in the lower left quadrant. Bore holes not in the carapace were located in the eyestalk or in the cuticle of the eye socket, in these cases the duration of the feeding sound was significantly shorter. The duration of the quiet periods are shortest at the initiation and at the completion of the bore hole. The central radula tooth can fit into the hole made in the shell of the crab and the characteristic pattern of wear indicates that it is subject to considerable abrasion when used. Chemical etching of the shell is involved in the formation of the bore hole. It is concluded that there is an alternation of periods of rasping by the radula and chemical etching during the making of the borehole.

Contents of this volume Sci. Mar. 61(Suppl.2) : 67-76 Back PDF
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