Settlement specifics: Effective induction of abalone settlement and metamorphosis corresponds to biomolecular composition of natural cues.

Chemical signaling plays a major role in shaping life history processes that drive ecology and evolution in marine systems, notably including habitat selection by marine invertebrate larvae that must settle out of the plankton onto the benthos.1 For larvae, the identification of appropriate habitats in which to settle and undergo metamorphosis to the adult form relies heavily on the recognition of cues indicative of a favorable environment. By documenting settlement responses of larvae of the tropical abalone, Haliotis asinina, to a range of coralline algae species, we recently highlighted the species-specific nature of this interaction.2 Here, we demonstrate that this specificity is likely driven by chemical, rather than physical, properties of the algae. Our initial characterization of the surface cell biomarkers from three different algal species shows that inductive cue biomolecular composition correlates with variations in larval settlement response.