Consumer feces impact coral health in guild-specific ways

Grupstra, C. G. B.; Howe-Kerr, L. I.; van der Meulen, J. A.; Veglia, A. J.; Coy, S. R.; Correa, A.

doi:10.1101/2022.10.31.514626

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bioRxiv · 10.1101/2022.10.31.514626

Consumer feces impact coral health in guild-specific ways

Grupstra, C. G. B.·Howe-Kerr, L. I.·van der Meulen, J. A.·Veglia, A. J.·Coy, S. R.·Correa, A.

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Abstract

Microbiota from consumer feces can impact resource species in guild-specific ways. We tested the effect of fresh and heat-killed feces from corallivorous (coral-eating) and grazer/detritivorous fish on coral health and found that fresh grazer/detritivore feces, but not fresh corallivore feces, affected coral health in detrimental ways compared to heat-killed feces, suggesting that microbiota in grazer/detritivore feces were harmful. Bacterial diversity across 10 fish species suggests our experimental findings are generalizable to consumer guild: corallivore feces contained more coral-associated bacteria, and lower abundances of the coral pathogen, Vibrio coralliilyticus. These findings recontextualize the ecological roles of consumers on coral reefs: although herbivores support coral dominance through removal of algal competitors, they also disperse coral pathogens. Corallivore predation can wound corals, yet their feces contain potentially beneficial coral-associated bacteria, supporting the hypothesized role of corallivores in coral symbiont dispersal. Such consumer-mediated microbial dispersal as demonstrated here has broad implications for environmental management.

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Grupstra, C. G. B., Howe-Kerr, L. I., van der Meulen, J. A., Veglia, A. J., Coy, S. R., Correa, A.. 2022-11-02. Consumer feces impact coral health in guild-specific ways. https://doi.org/10.1101/2022.10.31.514626

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