THE COPPER CONTENT AND COPPER TOLERANCE OF SOME SPECIES OF MOLLUSKS OF THE SOUTHERN CALIFORNIA COAST

¹ From the Scripps Institution of Oceanography, University of California, La Jolla, California

The copper content and concentration of several Species of mollusks has been determined with particular reference to variation with age or size. In the snail, Helix aspersa, the amount of copper per unit weight of tissue increases with increase in size, whereas it decreases in the California sea mussel. In the octopus, Polypus bimaculatus, it remains constant. Samples of sea water of the Pacific were found to contain 0.001 mg. of copper per kilogram. The upper limits of copper tolerance of a few species of marine mollusks, when kept in the laboratory under given conditions, lies in the range from 0.10 to 0.20 mg. of added copper per kilogram of sea water. The clam, Paphia staminea var. laciniata, can tolerate a much higher concentration than the above.