Future research directions of the model marine tubeworm Hydroides elegans and synthesis of developmental staging of the complete life cycle.

Background: The biofouling marine tube worm, Hydroides elegans, is an indirect developing polychaete with significance as a model organism for questions in developmental biology and the evolution of host‐microbe interactions. However, a complete description of the life cycle from fertilization through sexual maturity remains scattered in the literature, and lacks standardization. Results and discussion: Here, we present a unified staging scheme synthesizing the major morphological changes that occur during the entire life cycle of the animal. These data represent a complete record of the life cycle, and serve as a foundation for connecting molecular changes with morphology. Conclusions: The present synthesis and associated staging scheme are especially timely as this system gains traction within research communities. Characterizing the Hydroides life cycle is essential for investigating the molecular mechanisms that drive major developmental transitions, like metamorphosis, in response to bacteria. Key Findings: We have composed a staging scheme that summarizes the entire life cycle of Hydroides elegans. This includes early development, gastrulation, larval phases, metamorphosis, and post‐settlement maturation. Coalescing these periods in development into this staging scheme will further propel Hydroides forward as an important developmental model for the investigation of bacteria‐stimulated metamorphosis, among other exciting future prospects. [ABSTRACT FROM AUTHOR]