Rhodophyta (Red algae)
With over 4,000 species, most from marine habitats, the red algae range in morphology from simple unicells to unbranched and branched filaments to complex multiaxial uprights and crusts. Their pigments include chlorophyll a and the phycobiliproteins, red phycoerythrin (often the dominant pigment) and blue phycocyanin, as well as carotenes, lutein, zeaxanthin. Most reds have a complex life history with three phases: tetrasporophyte, gametophyte and carposporophyte. In fact, the post-fertilization development of the carposporophyte is the best part of each species' story. Red algae have no flagellated stages; their non-swimming sperm are called "spermatia." What are the odds of their success?