Time-lapse videomicroscopy of cell (spore) movement in red algae

Abstract

The red algae generally are considered to have no motile stages. We have confirmed sporadic reports of motile spores in a few red algae by recording freshly released live spores with time-lapse videomicroscopy. Of the 25+ species investigated, only a few had spores that appeared to be immobile. Cells of unicellular species often displayed active movement although were otherwise indistinguishable from nearby immobile cells, and these may be equivalent to the motile spores released after differentiation in more complex multicellular species. There was considerable variation among members of the Bangiophycidae. Cells of Porphyridium often moved at around 0·66 μm s1 and had conspicuous mucilage tails. Flintiella and Rhodospora showed no cellular movement. Rhodosorus sometimes moved a little and all four strains displayed continuous cytoplasmic rotation within the wall. Glaucosphaera was inert but displayed formation and transport of vesicles from the perinuclear region to the surface where they were discharge...