Predation on coral settlers by the corallivorous fireworm Hermodice carunculata

Coral predation by the fireworm Hermodice carunculata was investigated by presenting settlers (< 3-week-old) and adults of two species of Caribbean corals, Montastraea faveolata and Agaricia humilis, to three different size classes of fireworms under laboratory conditions. For both coral species, survival rates of settlers were low (< 2 % after 4 days), intermediate (42-54 %) and high (> 90 %) in the presence of small-, mid- and large-sized fireworms, respectively. In contrast, fireworms hardly preyed on adult corals, irrespective of their sizes. Our results suggest an ontogenic shift in the diet of H. carunculata and in the susceptibility of corals to predation by fireworms. H. carunculata, in particular small-sized individuals, could be an important cause for early post-settlement mortality in corals. The corallivore could reinforce recruitment bottlenecks and reduce coral recovery after disturbances.