Cryptomonadida

(biology) An order of the class Phytamastigophorea considered to be protozoans by biologists and algae by botanists.

An order of the class Phytamastigophorea, also known as the Cryptomonadina. Cryptomonads are considered to be protozoans by zoologists and algae by botanists. Most species occur in fresh water. They are olivegreen, blue, red, brown, or colorless. All flagellated members have two subequal flagella inserted in a gullet opening through an obliquely truncate anterior end (see illustration). Although few in genera and species, Cryptomonadida form extensive marine and fresh-water blooms. See also Protozoa.

Examples of cryptomonads. (a) Chilomonas paramecium. (b) Cryptomonas erosa.