MECHANICAL AND MORPHOLOGICAL PROPERTIES OF THE SHELL OF SCROBICULARIA PLANA (DA COSTA) UNDER NORMAL AND STRESS CONDITIONS

Scrobicularia plana reacts to salinity stress by closing itsvalves and respiring anaerobically. The acidic products of respirationare buffered by calcium carbonate removed from the shell. Shellmass decreases by 15% over a period of three weeks, and thereis a similar reduction in shell strength. Erosion of the shell surface, indicating buffering, takes placequickly, pits can be seen in the valves of shells at the endof six hours of normal intertidal emersion. (Received 10 February 1982;