LAUSR

Many life history traits relate to trade-offs among an organism’s energy investments in growth, reproduction, and maintenance, as well as to fundamental physiological processes or body size. Other traits reflect affordances, or possibilities enabled by an investment strategy. In scleractinian corals, growth and reproduction have been studied to a much greater extent than maintenance. Species traits likely to correlate or trade off with maintenance investments include those relating to colony growth, reproduction, and susceptibility to bleaching. Here, we measure tissue biomass per cm2 for 29 Caribbean reef corals and evaluate whether the more easily measured corallite diameter is a proxy for tissue biomass as is often assumed. We examine hypotheses concerning corallite size and tissue biomass on the one hand, and growth rate, reproduction, competitive ability, and bleaching susceptibility on the other. Our results indicate that biomass per unit area ranges from one to two orders of magnitude across species, that corallite size is a weak predictor of tissue biomass per cm2, and that tissue biomass is strongly correlated with growth rate and competitive ability. Relationships between biomass or module size and reproductive characteristics or bleaching susceptibility are not evident in this set of Caribbean corals. These findings expand our understanding about energy investment strategies in colonial corals and suggest that biomass may be an important metric to consider in cross-species comparisons, especially among corals from different families. Finally, this work can help inform predictions of reef response to continued threats.