Effects of tropical solar radiation on the motility of filamentous cyanobacteria

Abstract The effects of tropical solar radiation on the motility of the cyanobacteria Anabaena variabilis, Oscillatoria tenuis and two strains of Phormidium uncinatum were studied in Ghana (4.30°N). The percentages of motile filaments were drastically reduced by unfiltered solar radiation. Covering the organisms with various long pass or band pass filters (WG320, GG395 or UG5) revealed that the UV‐B, UV‐A and visible light components of the solar spectrum were all effective in impairing motility in these organisms. Only partial recovery was observed and only after short exposure times. Copyright © 1993, Wiley Blackwell. All rights reserved