THE USE OF MOLLUSCAN SHELL GROWTH PATTERNS IN ECOLOGY AND PALEOECOLOGY

The influence of substratum, depth of water, turbidity, and temperature on daily growth patterns has been studied by transplanting juvenile Mercenaria mercenaria (Linnaeus) from the laboratory to intertidal and subtidal environments. The study of seasonal growth variations in a population of Gemma gemma Totten from Long Island Sound shows that shell growth patterns may be used to determine the season of death and age of dead shells. Deep-water species (e.g. Nucula cancellata Jeffreys, Malletia sp., and Calyptogena ponderosa Boss) exhibit growth increments that are more uniform in thickness and less sharply defined than those in shallow-water species.