Editor: Patricia Sobecky
Lack of endosymbiont release by two Lucinidae (Bivalvia) of the genus Codakia: consequences for symbiotic relationships
Article first published online: 16 DEC 2008
Journal compilation © 2008 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. No claim to original French government works
FEMS Microbiology Ecology
Volume 67, Issue 2, pages 261–267, February 2009
How to Cite
Brissac, T., Gros, O. and Merçot, H. (2009), Lack of endosymbiont release by two Lucinidae (Bivalvia) of the genus Codakia: consequences for symbiotic relationships. FEMS Microbiology Ecology, 67: 261–267. doi: 10.1111/j.1574-6941.2008.00626.x
- Issue published online: 22 DEC 2008
- Article first published online: 16 DEC 2008
- Received 26 June 2008; revised 26 September 2008; accepted 27 October 2008.First published online 16 December 2008.
- sulfur-oxidizing gill endosymbiont;
- transmission mode
Associations between marine invertebrates and chemoautotrophic bacteria constitute a wide field for the study of symbiotic associations. In these interactions, symbiont transmission must represent the cornerstone allowing the persistence of the association throughout generations. Within Bivalvia, in families such as Solemyidae or Vesicomyidae, symbiont transmission is undoubtedly vertical. However, in Lucinidae, symbiont transmission is described in the literature as ‘environmental’, symbionts being acquired from the environment by the new host generations. Hence, if there is transmission, symbionts should be transmitted from adults to juveniles via the environment. Consequently, we should observe a release of the symbiont by adults. We attempted to detect such a release within two Lucinidae species of the genus Codakia. We sampled 10 Codakia orbicularis and 20 Codakia orbiculata distributed in 10 crystallizing dishes containing filtered seawater. During 1 month of investigation, we analyzed water of the dishes in order to detect any release of a symbiont using catalyzed report deposition-FISH techniques. For 140 observations realized during this period, we did not observe any release of symbionts. This suggests that the idea of host-to-host passage in Lucinidae is inaccurate. We could therefore consider that the transmission mode from generation to generation does not occur within Lucinidae, symbiosis appearing to be advantageous in this case only for the host, and constitutes an evolutionary dead-end for the bacteria.