CRYPTOMONAD

any small biflagellate organism considered both as a protozoan (order Cryptomonadida) and as an alga (class Cryptophyceae). Occurring in both fresh and salt water, cryptomonads contain pigments found only in red and blue-green algae, and sometimes they live harmlessly as zooxanthellae within other organisms. Cryptomonas, a typical photosynthetic genus, has two unequal flagella attached at one end of a flattened oval cell. Chilomonas does not have chromatophores (pigment-containing structures) and ingests organic matter; under certain conditions it may survive on minerals alone. Cryptomonads encyst in a spherical cellulose case and reproduce asexually in either the motile or inactive state. See also zooxanthella.