The chlorarachniophytes are a small group of exclusively marine algae widely distributed in tropical and temperate waters.
[5] They are surrounded by four membranes, the outermost of which is continuous with the endoplasmic reticulum, and contain a small nucleomorph between the middle two, which is a remnant of the alga's nucleus.
The origin of the chloroplasts from green algae is supported by their pigmentation, which includes chlorophylls a and b, and by genetic similarities.
The chlorarachniophytes only include five genera, which show some variation in their life-cycles and may lack one or two of the stages described above.
Genetic studies place them among the Cercozoa, a diverse group of amoeboid and amoeboid-like[clarification needed] protozoa.