INTERTIDAL ZONE-FORMATION IN POMATOLEIOS KRAUSSII (ANNELIDA: POLYCHAETA)

¹ Hawaii Institute of Marine Biology, University of Hawaii, Kaneoke, Hawaii 96744

Pomatoleios kraussii forms an intertidal zone which extends from 0.5 to 0.9 feet above datum in the sheltered areas of Kaneohe Bay. The settlement range which extends subtidally, is wider than the adult survival range which in turn is wider than the Pomatoleios zone. The settlement range moves up and down the shore corresponding to seasonal changes in the level of minimum High Water Springs. The Pomatoleios zone is limited at the top by exposure to air and predation, and at the bottom by competition for space. Habitat selection within the settlement zone is influenced by surface texture, surface angle, exposure to currents, presence of sand and algae. Competition for space with Balanus, Ostrea, and vermetids is largely eliminated by different larval settlement preferences in these species.