Abstract
Asteromonas gracilisArtari remains motile throughout cell division. Basal bodies separate and replicate at prophase. They are located lateral to the poles of the closed metaphase spindle. Kinetochores appear at late metaphase. Chromosomes move to the poles and extensions of the nuclear envelope develop into the pyrenoid at anaphase. The interzonal spindle disintegrates at telophase and a diffuse phycoplast is present. Cytokinesis proceeds rapidly from the anterior region of the cell. Newly formed daughter cells have four narrow‐banded rootlets and both distal and proximal fibers connect the basal bodies. Features of cell division inAsteromonasare compared to those in other algae, particularlyDunaliellaandChlamydomonas.