LABORATORY EVIDENCE FOR DELAY OF LARVAL SETTLEMENT IN RESPONSE TO A DOMINANT COMPETITOR

Abstract

In nature, the marine bryozoan, Bugula pacifica, is consistently the ‘loser’ when competing for space with the compound ascidian, Diplosoma macdonaldi. We provide laboratory evidence to show that Bugula larvae will delay settling in either ‘Diplosoma-conditioned water’ or an alcohol Diplosoma extract. It is reasoned that the delay response is elicited by an inhibitory factor released continually from Diplosoma. This response is reversible, non-pathological, and species specific. The possible ecological significance of larval avoidance behavior in this and other communities is discussed.