Abstract
Observations were made on the succession and growth rates of crustose coralline algae growing in situ on artificial substrata in a shallow fore-reef environment on Ishigaki Island, Ryukyu Islands. Succession in well-illuminated environments manifests itself as a gradual replacement of species having very thin thalli by those having larger and thicker thalli. The species Porolithon onkodes, Paragoniolithon conicum and Lithophyllum insipidum achieved dominance by competitive interactions of overgrowing margins. The thicker species recruit quickly (within the first few months), but because of their slow growth rate do not displace the pioneer species that have very thin thalli until after the latter begin to die. Regardless of seasonal temperature fluctuations, which exceed 10 °C, the coralline algal succession is the same for each season. The maximum lateral growth rates of the major species range between 2.9 and 3.9 mm/month. Vertical growth rates of Porolithon onkodes, the thickest species, are the most rapid (more than 2 mm/year at maximum) relative to those of other species. Accretion rates of entire coralline algal cover on ungrazed substrata range from 1.0 to 1.2 mm/year (not allowing any lag time for recruitment), whereas those of grazed substrata are lower. These results are consistent with species which are ecological equivalents and live in similar environments on Caribbean reefs.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.