Meeting Abstract
Community dynamics in benthic marine ecosystems are largely driven by larval settlement, which relies on larvae selecting suitable environments based on the integration of sensory cues. However, the sensory modalities that most affect larval settlement decisions are poorly understood in most systems. The benthic marine hydroid Ectopleura crocea has an indirect lifecycle that produces a motile larval stage called actinula. While researchers have previously investigated the biology of settlement in actinulae, no study has combined sensory behavior experiments with genomics studies. Here we examine the settlement response of actinula to different light and chemical environments in conjunction with a developmental transcriptome study investigating sensory gene expression. We hypothesize that larval settlement will be most influenced by the combination of biofilm-derived chemical cues and light cues, and that actinula will differentially express taste and chemoreceptors during stages where larvae are competent to settle. We test these hypotheses by combining RNA-seq on various stages of actinula development, from actinula through metamorphosis, with settlement experiments under different sensory conditions. Additionally, we use confocal microscopy at various developmental stages to explore the development of the neural network and its capabilities of sensory integration. Ultimately, our investigations of actinula larva at the molecular level will provide insights into the sensory modalities that influence the settlement decision.
