[en] Analyses of the natural abundance of carbon and nitrogen stable isotopes were performed to investigate the feeding habits of two ophiuroids, Ophiomastix venose 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 0. 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.
Disciplines :
Zoology
Author, co-author :
Fourgon, D.
Lepoint, G.
Eeckhaut, Igor ; Université de Mons > Faculté des Sciences > Biologie des Organismes Marins et Biomimétisme
Language :
English
Title :
Assessment of trophic relationships between symbiotic tropical ophiuroids using C and N stable isotope analysis
Publication date :
01 January 2006
Journal title :
Journal of the Marine Biological Association of the United Kingdom
ISSN :
0025-3154
Publisher :
Cambridge University Press, United Kingdom
Volume :
86
Issue :
6
Pages :
1443-1447
Peer reviewed :
Peer Reviewed verified by ORBi
Research unit :
S864 - Biologie des Organismes Marins et Biomimétisme
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