I was co-advised by Drs Deborah Robertson (Clark University) & Gretchen Goodbody-Gringley (Bermuda Institute of Ocean Sciences). My masters research explored the symbiotic partnerships between the mustard hill coral, Porites astreoides and microalgae (dinoflagellate family Symbiodiniaceae) during early life stages. P. astreoides is a great lab rat because of its weedy life history (grows well in harsh environments, high fecundity & settlement rates). The coral reefs of Bermuda are an ideal study system because of the high connectivity levels between P. astreoides between P. astreoides from reef sites that differ in environmental conditions (e.g. shallow lagoonal reef flat, shallow fringing reef, mesophotic “deep” reefs). The fidelity between P. astreoides maintained and its dominant symbiont (Symbiodinium A4) remained steadfast in different reef environments and life stages (planulae, juvenile, adult). However, in situ (reef) reared juveniles demonstrated faster growth rates and were more likely to harbor background Symbiodiniaceae from additional genera (Breviolum, Cladocopium) compared to laboratory reared juveniles. Ultimately, these results emphasize the paradox between the long-term, intergenerational specificity of cnidarians and their dinoflagellate partners in addition to their ability to obtain low-levels of background diversity.