This project aims to examine genetic characteristics of P. astreoides planulae and adults from shallow (10 m) and mesophotic (45 m) reefs, to assess the vertical genetic connectivity and elucidate the mechanisms underlying the plasticity of P. astreoides across life stages that enable them to survive across broad depth gradients. Exploring such plasticity will ultimately advance our understanding of these ecosystems and the potential for mesophotic reefs to serve as refugia.