Settlement and early post-settlement survival in the recruitment of Mulinia lateralis (Bivalvia)

Recruitment of benthic invertebrates involves settlement and early post-larval survival.In soft-sediment habitats these 2 events generally have not been distinguished despite the fact that they may lead to different interpretations of the processes affecting recruitment.Settlement and early postlarval survival of the bivalve Mulinla lateralis (Say) i n a natural infaunal community were recorded and the 2 phenomena distinguished.M. lateralls settled in large numbers (514 0.01 m-') into a n intertidal infaunal community characterized by high but variable densities of the tubicolous polychaete Diopatra cuprea (Bosc).Settlement density was variable but did not differ between sites with and without D. cuprea tubes.Early post-larval (within 1 mo) survival/persistence was lower in sites with high densities of D. cuprea and in sites which were bounded by high densit~es of D. cuprea than in sites without D. cuprea.Rapid changes in M. lateralis abundance after settlement and differential survival between microhabitats led to distribution patterns which after 1 mo differed substantially from initial settlement patterns.Attempts to evaluate processes which lead to observed recruitment patterns must first distinguish between these 2 events.