Abstract

For many marine invertebrates, larval settlement is a key developmental transition. This process is strongly linked to the environment in that larvae must detect specific cues to determine the time and place of settlement. How environmental cues are detected and activate internal hormone signalling to regulate larval settlement is not yet clear. To better understand this, we are investigating larval settlement in the nereid polychaete Platynereis dumerilii. Behavioural assays show that Platynereis larvae have a species-specific response to biofilms composed of benthic microalgal diatoms. Platynereis larval settlement is internally regulated by the neuropeptide myoinhibitory peptide (MIP), an ortholog of insect allatostatin B neuropeptide. I will discuss recent advances in understanding the function and signalling mechanisms of MIP and assessing its link to environmental cue detection in Platynereis. Understanding how external and internal signals combine to guide the developmental transition of marine invertebrate settlement will inform our understanding of animal-microalgae interactions and the evolution of environmentally-guided animal development.