Assessment of trophic relationships between symbiotic tropical ophiuroids using C and N stable isotope analysis
Fourgon, D.; Lepoint, G.; Eeckhaut, I. (2006). Assessment of trophic relationships between symbiotic tropical ophiuroids using C and N stable isotope analysis. J. Mar. Biol. Ass. U.K. 86(6): 1443-1447. dx.doi.org/10.1017/S0025315406014494 In: Journal of the Marine Biological Association of the United Kingdom. Cambridge University Press/Marine Biological Association of the United Kingdom: Cambridge. ISSN 0025-3154; e-ISSN 1469-7769, more |  |
| Keywords | Environments > Aquatic environment
Interspecific relationships
Interspecific relationships > Symbiosis
Echinodermata [WoRMS]
Marine/Coastal |
| Abstract | Analyses of the natural abundance of carbon and nitrogen stable isotopes were performed to investigate the feeding habits of two ophiuroids, Ophiomastix venosa and Ophiocoma scolopendrina, and to assess the potential benefit obtained by the symbiotic Ophiomastix venosa juveniles. A tracer experiment was also carried out to clarify the contribution of algae to the nitrogen uptake amongst the tested ophiuroids. Our results suggest that Ophiocoma scolopendrina adults occupy a higher position in the food web than Ophiomastix venosa and mainly feed on neuston. In contrast, O. venosa adults feed on the alga Sargassum densifolium and on organic matter associated with sediment. Free juveniles and symbiotic juveniles of O. venosa have intermediate d13C values between both adult species. The high proportion of 13C in the symbiotic juveniles compared to the one in their conspecific adults indicates that their diet slightly differs from the latter and is closer to that of Ophiocoma scolopendrina. This raises the hypothesis that symbiotic juveniles steal neuston from their associated host, O. scolopendrina. |
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