Vent Algae
Algeara redensis is a benthic chemosynthetic Algeayan. It grows around hydrothermal vents in the deep ocean where it can obtain hydrogen sulfide for chemosynthesis. They grow in strands of cells that float near or rest at the bottom of the ocean. They collect and store dense materials that allow them to sink. A. redensis has a red pigment because it is descended from a purely photosynthetic ancestor and some accessory pigments remain that give it a red appearance. The red pigment does allow the organism to survive for brief periods if it does end up in an area away from hydrothermal vents with light exposure.
A. redensis reproduces through fragmentation of the strands. The strands are produced by cellular mitosis. In areas with little disturbances they can create thick matts on the seafloor giving the substrate a reddish appearance.