The Performance of an Intertidal Predator Thais lapillus, in Relation to Structural Heterogeneity

Abstract

(1) The influence of substratum heterogeneity on the performance (prey selection, predation rate, protection against high temperatures, desiccation and wave action, growth rates, substratum preference) of the northern Atlantic intertidal predator, Thais (Nucella) lapillus L. was examined experimentally in the field. (2) Dogwhelks had higher growth rates on heterogeneous than on homogeneous surfaces. (3) Barnacles were of higher quality as prey and varied less in abundance on heterogeneous than on homogeneous substrata. (4) Dogwhelks were better protected against wave action on heterogeneous than on homogeneous substrata. (5) Dogwhelks strongly preferred heterogeneous over homogeneous substrata. (6) Dogwhelk performance was higher on heterogeneous than on homogeneous substrata.