Phylum Cryptophyta, commonly known as cryptomonads, is a group of unicellular eukaryotic algae. Some synonyms for this phylum include cryptophytes, cryptomonads, and cryptomonadales. These organisms are characterized by their two flagella, which allow them to move through the water with ease. Cryptophytes can be found in both marine and freshwater environments, and are important primary producers in aquatic ecosystems. Some notable species include Cryptomonas and Hemiselmis, both of which are commonly used in laboratory studies. Originally classified as a type of algae, recent genetic analysis has suggested that Cryptophyta may actually be more closely related to plants.