Dissolved histamine: a potential habitat marker promoting settlement and metamorphosis in sea urchin larvae

摘要: Many species of marine invertebrate larvae settle and metamorphose in response to chemicals produced by organisms associated with the adult habitat, histamine is a cue for sea urchin Holopneustes purpurascens. This study investigated effect on larval metamorphosis six species. Histamine induced three lecithotrophic (H. purpurascens, inflatus Heliocidaris erythrogramma) one planktotrophic (Centrostephanus rodgersii). Direct comparisons metamorphic rates assays cannot be made due different proportions being competent. (10 μM) 95% H. purpurascens after 1 h, while coralline alga Amphiroa anceps 40–50% these larvae. A. 40 80% metamorphosis, respectively, erythrogramma 24 h. Corallina sp. 30 70% C. rodgersii No any occurred seawater controls. Larvae two (Tripneustes gratilla tuberculata) did not histamine. Seagrasses, host plants inflatus, rapid species, several algae leaching from seagrasses may act as habitat marker ecologically important