MEPS 465:111-117 (2012)  -  DOI: https://doi.org/10.3354/meps09904

ABSTRACT: Competition for space is intense among sessile benthic organisms on coral reefs. Despite this, the commonly observed interaction between the sponge Mycale laevis and scleractinian corals has been considered a mutualism in which the sponge gains substratum for growth on the undersides of coral colonies, and corals receive protection from boring sponges as well as increased food supply from the exhalant water of surrounding sponge oscules. In previous studies, we demonstrated that M. laevis is chemically undefended from predators and gains a refuge from sponge-eating fishes by growing among the branches and plates of hard corals. In this study, we investigated the putative benefits of the sponge to the coral host in the presence and absence of spongivores. Specifically, we examined whether the sponge reduced infestation of the coral skeleton by boring sponges, whether corals associated with sponges had higher reproductive output reflecting enhanced food availability and whether the boundary between the 2 species was stable over time. Regardless of the presence of spongivores, association with M. laevis neither affected the frequency of colonization of Montastraea annularis by boring sponges, nor increased reproductive output of Montastraea franksi. On overfished reefs off Panama, M. laevis overgrew its coral hosts, while off the Florida coast, where sponge-eating fishes are abundant, the sponge had a semi-cryptic growth form and little impact on associated corals. Corals do not gain any benefit from M. laevis on reefs protected from overfishing, but suffer negative effects when sponge predators are removed.

KEY WORDS: Mutualism · Symbiosis · Context dependence · Conditional · Caribbean · Overgrowth · Montastraea

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Cite this article as: Loh TL, Pawlik JR (2012) Friend or foe? No evidence that association with the sponge Mycale laevis provides a benefit to corals of the genus Montastraea. Mar Ecol Prog Ser 465:111-117. https://doi.org/10.3354/meps09904 Export citation Share:    Facebook - - linkedIn