[en] Analyses of the natural abundance of carbon and nitrogen stable isotopes were performed to investigate the feeding habits of two ophiurolds, 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 ophiurolds. 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 PC values between both adult species. The high proportion of C-13 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 front their associated host, O. scolopendrina.
Research Center/Unit :
MARE - Centre Interfacultaire de Recherches en Océanologie - ULiège
Disciplines :
Aquatic sciences & oceanology
Author, co-author :
Fourgon, Didier
Lepoint, Gilles ; Université de Liège - ULiège > Département des sciences et gestion de l'environnement > Océanologie
Eeckhaut, Igor
Language :
English
Title :
Assessment of trophic relationships between symbiotic tropical ophiuroids using C and N stable isotope analysis
Publication date :
December 2006
Journal title :
Journal of the Marine Biological Association of the United Kingdom
ISSN :
0025-3154
eISSN :
1469-7769
Publisher :
Cambridge Univ Press, New York, United States - New York
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