Species and size matter: An experimental study of microhabitat use under the influence of competitive interactions in intertidal gobiids

► We examine how biotic interactions affect microhabitat use in intertidal gobies. ► We manipulate the identity and body size of paired fish in laboratory experiments. ► Microhabitat use varies with the identity/size of a paired individual. ► Diel patterns of habitat use may be different among gobiid species. ► Intertidal gobies show flexible habitat use under variable conditions.