MEPS 368:137-143 (2008)  -  DOI: https://doi.org/10.3354/meps07615

ABSTRACT: Fundamental theories of resource allocation for terrestrial plants predict that species investing in chemical defenses should be slow growing or less fecund, while undefended species should mitigate consumer effects by diverting energy to growth and reproduction, thereby also enhancing their ability to colonize open space. As for some plant communities, sponges on Caribbean coral reefs include chemically defended species and undefended species that tolerate consumer damage. We surveyed the sponge community on the 155 m long wreck of the USS ‘Spiegel Grove’ (~1583 m² deck surface), which was intentionally sunk 4 yr previously in 2002 as an artificial reef off Key Largo, Florida, USA, to determine the relative abundance of undefended and defended species on previously uncolonized habitat compared to an adjacent reef at a similar depth and with similar topography. As predicted by theory, chemically undefended sponge species were significantly more abundant (96.0%) and larger on the shipwreck than on adjacent coral reef (15.2%; G-test, p < 0.0001). On a subsequent survey 18 mo later, the first recruits of 6 chemically defended sponge species were discovered, suggesting that the sponge community on the wreck is in transition toward that occurring on adjacent reefs. Although more definitive replicated experiments remain to be performed, these results corroborate the resource trade-off hypothesis as applied to the evolution of chemical defenses among sponge species on Caribbean reefs.

KEY WORDS: Predation · Optimal defense · Tolerance · Coral reef