Strength of interactions between species can vary in space and time. For example, nets of vermetid gastropod, Ceraesignum maximum, cover corals and can lead to reduced coral growth and survival. However, the strength of this effect varies. We hypothesized that this variation reflected differences in the historical exposure of coral colonies to vermetids: i.e., prior exposure to vermetids induced a change in phenotype, enhancing the tolerance of corals to subsequent exposure to vermetids. We tested this hypothesis of adaptive plasticity in a reciprocal transplant study using corals from reefs naturally with vs. without vermetids.
Results/Conclusions
After five months, we found that both prior exposure and transplant locations had significant effects on calcification and tissue thickness. Corals without prior exposure to vermetids achieved only 67% of the growth of corals exposed to vermetids, but had 44% thicker tissues. Regardless of origin, coral calcification was reduced by 50%, but tissue thickness was unaffected, by transplant location. We conclude that there are differences in corals exposed to versus protected from vermetids. Additionally, results suggest that the potential fate of a coral is canalized by early environmental conditions and may not be malleable on month-long scales even after the environment shifts. We hypothesize that the potential mechanisms underlying these growth responses are reflected in coral microbial communities, and we will further investigate the link between the response of the coral holobiont to historical and current vermetid exposure and alterations in their microbial community.