Chemical defenses against generalist fish predators and fouling organisms in two invasive ahermatypic corals in the genus Tubastraea |
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| Authors: | Bruno G Lages Beatriz G Fleury Angelo C Pinto Joel C Creed |
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| Institution: | 1. Programa de Pós‐Gradua??o em Ecologia e Evolu??o, Universidade do Estado do Rio de Janeiro – UERJ, PHLC Sala 224, Rua S?o Francisco Xavier 524, 20.559–900 Rio de Janeiro, RJ, Brazil;2. Departamento de Ecologia, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro – UERJ, PHLC Sala 220, Rua S?o Francisco Xavier 524, 20.559–900 Rio de Janeiro, RJ, Brazil;3. Departamento de Química Organica, Instituto de Química, Universidade Federal do Rio de Janeiro – UFRJ, Bloco A, CT, Avenida Athos da Silveira Ramos 149, 21.941–909 Rio de Janeiro, RJ, Brazil |
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| Abstract: | The introduction of exotic marine species has caused considerable economic and ecological damage around the world. Some of these species possess adaptations such as secondary metabolites which facilitate their successful invasion into new areas. In this study we tested two hypotheses: (i) crude extracts produced by two invasive hard corals Tubastraea coccinea and Tubastraea tagusensis, introduced to the southwest Atlantic, inhibit predation by generalist fish; (ii) substances found in the crude extracts of both species reduce or enhance the settlement of other organisms. In an in situ palatability bioassay the extract of T. tagusensis reduced predation by generalist fish. The extracts of both species of coral showed species‐specific effects on fouling organisms in in situ gel plate bioassays. Control and extract plates had similar total cover, although plates with extracts had significantly fewer Cladophora sp., and Lithophyllum sp. was only detected on control gels. In contrast, a hydrozoan was only found on plates with extracts and overall community ordination demonstrated clear differences in the fouling communities between treatments. These results demonstrate that both coral species have chemical substances which can bring about a negative interaction with potential fish predators and competitors such as algal and invertebrate foulers and the advantage gained could explain their success in invading new regions to the detriment of local fauna and flora. |
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| Keywords: | Antifouling chemical defense introduced species predation Tubastraea coccinea Tubastraea tagusensis |
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