Chlamydomonas
 Chlamydomonas is a genus of green algae consisting of unicellular flagellates found in stagnant water and on damp soil in freshwater seawater and even in snow as snow algae. Chlamydomonas is used as a model organism for molecular biology especially studies of flagellar motility and chloroplast dynamics biogeneses and genetics. One of the many striking features of Chlamydomonas is that it contains ion channels (channelrhodopsins) that are directly activated by light.