The effects of low metal levels on a clonal hydroid

Abstract

A sensitive and precise bioassay has been developed, using the colonial hydroid Campanularia flexuosa, for measuring the sublethal effects of marine contaminants in terms of the inhibition of colonial growth rate. A single clone can be cultured simply in the laboratory for indefinite periods. Thresholds of sensitivity to three metals in 11-day experiments were Hg2+ 1.6-1.7μg/1, Cu2+ 10-13μg/l, Cd2+ 110-280μg/l. Observations on the development of the hydroid's response with time shows that sensitivity increases linearly at first, but during the second week the metals have a transitory stimulatory effect on colonial growth rate which is known as the Arndt-Schulz Effect. © 1976, Marine Biological Association of the United Kingdom. All rights reserved.