Cryptophyta

Cryptophyta, also known as cryptomonads, are a group of small, biflagellate algae found in both freshwater and saltwater environments. They are notable for possessing pigments similar to those found in red algae and cyanobacteria. Some cryptomonads live symbiotically within other organisms.1

Their classification is debated due to possessing both plant-like and animal-like characteristics, with some scientists considering them protozoans rather than algae. A typical genus, Cryptomonas, has two unequal flagella and can form water blooms, though they are not known to be toxic. Another genus, Chilomonas, lacks pigment and obtains nutrients by ingesting organic matter. Cryptomonads have no fossil record, making their evolutionary history difficult to trace.12