Order Zygnemales is a term used in biology to refer to a group of freshwater algae that are known for their unique zig-zag patterns of cell walls. Other synonyms for Order Zygnemales include Conjugales and Desmidiaceae. Desmids are small, single-celled organisms that are often used in studies of ecology and evolution because of their unique morphology and behavior. Some other synonyms that are sometimes used to refer to this group of organisms include Zygnematales, Mesotaeniaceae, and Spirogyrales. Despite the different names that are used to refer to these algae, they all share many common characteristics and are important components of freshwater ecosystems around the world.