A device for the collection and study of wood-boring molluscs: Application to boring rates and boring movements of the shipwormBankia gouldi

A device consisting of thin wood sheets bolted between transparent plastic plates has proved useful for the collection of wood-boring molluscs. The device makes possible measurements of rates of boring of individual animalsin situ, observations of boring movements, and simplified removal of intact animals from the wood substrate. Rates of boring of the shipwormBankia gouldi observed at intervals of a few days ranged from 0.03 to 3.85 mm per day, increasing with increasing length of the animal. Calculated growth curves indicated that growth was exponential. No significant difference in average boring rates was found between animals maintained in running sea water filtered through 5-μm mesh in the laboratory and animals maintained under field conditions. Extension of the burrow was observed to be accomplished by anterior-posterior and rotational dorsoventral movements of the valves.