Buoyancy regulation and chromatic adaptation in planktonic Oscillatoria species: alternative strategies for optimising light absorption in stratified lakes
Utkilen, Hans Chr.; Skulberg, Olav M.; Walsby, A. E.
Archiv für Hydrobiologie Volume 104 Number 3 (1985), p. 407 - 417
31 references
published: Sep 12, 1985
DOI: 10.1127/archiv-hydrobiol/104/1985/407
ArtNo. ESP141010403007, Price: 29.00 €
Abstract
On the basis of investigations into ten planktonic strains of Oscillatoria we propose that they may employ three distinct strategies for optimising their use of the natural light field. Green-coloured strains may exploit the higher light intensities of the epilimnion of lakes; they have weak gas vesicles that may be regulated by turgor pressure to provide a means of controlling buoyancy in shallow waters. Red-coloured strains may be adapted to absorbing the green light reaching the deeper metalimnion where these forms may stratify; their buoyancy is provided by stronger gas vesicles that can withstand the greater hydrostatic pressures in deeper lakes. A third type of Oscillatoria strain, which lacks gas vesicles and would be unable to regulate its buoyancy, exhibits chromatic adaptation and should be able to adjust its light absorption according to the incident light field at different depths. These different strategies would permit the different species to occupy different limnetic niches.
Keywords
plankton • Oscillatoria • lake