THE RATE OF WATER PROPULSION BY THE CALIFORNIA MUSSEL

Abstract

A simple and reliable method is descr. for determining the approximate average rate at which the California mussel, Mytilus californianus, propels water through its gill chambers during normal feeding, respirational and excretdry activities. The method consists of microchemical analyses at frequent intervals of the quantity of CaCO3 remaining in suspension in a given volume of continually stirred sea water containing the mussels, which filter out the suspended material as they pass the water through their gill chambers. Mathematical treatment and interpretation of the data obtained from experiments support the conclusions that (1) virtually all of the suspended matter is removed as the mussel propels the water over and through the capillary and other mucous surfaces of its gills and mantle; (2) the mussel propels the water rhythmically through its filtering system which on an average is constant, varying according to size and perhaps also according to other physiological attributes of the animals. Medium-sized animals (i.e., ranging in shell-length from 95 to 130 mm.) propelled water, at temp. close to 20[degree]C, at rates from 2.2 to 2.9 liters per hr., with an average of about 2.6 liters per hr.