Nitrogen fixation and symbionts associated with Hydrocoral millepora
- Autor(in)
- Seitenbereich
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197 - 203
- Zusammenfsg.
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The highest rate of nitrogen fixation (up to 160 ng N fresh wt.-1 h-1 ocurred in bladed and boxwork forms of the hydrocoral Millepora (Milleporina, Coelenterata) from the Indian Ocean and the South China Sea. No substantial nitrogen fixation occurred in branched forms. The level of nitrogenase activity was correlated with the amount of multicellular green microalgae in the hydrocoral skeleton. Not only zooxanthellae (Gymnodinium sp.) but also unicellular green algae (22 μ diameter), microalgae similar to Prochloron (Chloroxybacteria), and bacteria occur in the skeletons of living Millepora. The possible role of separate components of this symbiotic association in nitrogen fixation is discussed.