Growth Rates of the Sea Urchin Strongylocentrotus Purpuratus Related to Food Availability and Spine Abrasion

Abstract

A population of the purple sea urchin Strongylocentrotus purpuratus Stimpson was studied at Sunset Bay, Oregon. Three sub—populations had different size—frequency distributions. Such differences in size resulted from differences in growth rate and ultimate size. Two environmental components were examined as possibly causing the different rates of growth: a component of "weather" which broke spines, and food availability and consumption. These two components are important in determining growth rate and ultimate size of these animals.