Abstract
Despite advances in understanding the ecological functions of secondary metabolites from marine organisms, there has been little focus on the influence of chemically-defended species at the community level. Several compounds have been isolated from the gorgonian octocoral Phyllogorgia dilatata, a conspicuous species that forms dense canopies on rocky reefs of northern Rio de Janeiro State, Brazil. Manipulative experiments were performed to study: (1) the effects of live colonies of P. dilatata (physical presence and chemistry) on recruitment of sympatric benthic organisms; (2) the allelopathic effects of its chemicals on competitors; and (3) chemotactic responses of the non-indigenous brittle star, Ophiothela mirabilis. Early establishment of benthic species was influenced on substrates around live P. dilatata colonies and some effects could be attributed to the gorgonian’s secondary metabolites.In addition, the gorgonian chemicals also exerted an allelopathic effect on the sympatric zoanthid Palythoa caribaeorum, and positive chemotaxis upon O. mirabilis. These results indicate multiple ecological roles of a chemically-defended gorgonian on settlement, sympatric competitors, and non-indigenous species.
Highlights
Gorgonians are benthic marine invertebrates that occur in a wide range of habitats, from Arctic (Andrews et al, 2002) to Antarctic regions (Elias-Piera et al, 2013), and from intertidal waters (Yoshioka, 2009) down to deep-sea abysses (Mortensen & Buhl-Mortensen, 2005)
At the first monitoring (T1, 16 days), there was no difference between cover of the zoanthid P. caribaeorum over diffusion chambers with and without crude extract of P. dilatata (Wilcoxon test: Z = 1.8, p = 0.074, n = 6)
Diffusion control gels retrieved from the field were re-extracted and thin layer chromatography (TLC) analysis revealed that overall chemical profiles were similar throughout the experiment
Summary
Gorgonians (octocoral sea fans) are benthic marine invertebrates that occur in a wide range of habitats, from Arctic (Andrews et al, 2002) to Antarctic regions (Elias-Piera et al, 2013), and from intertidal waters (Yoshioka, 2009) down to deep-sea abysses (Mortensen & Buhl-Mortensen, 2005). Most gorgonian species occur in tropical and sub-tropical marine waters (Alderslade, 1984). Given their diverse ecological range, many factors have been reported as being involved in the distribution of gorgonians, such as irradiance (Lasker, 2003), depth (Mortensen & Buhl-Mortensen, 2005), temperature (Ferrier-Pagés et al, 2009), substrate availability (Weinbauer & Velimirov, 1996), bottom sediment transport (Yoshioka, 2009) and topography (Tong et al, 2012).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
