"dunaliella" is a biflagellate green algal and mostly marine protist that, in its vegetative motile form and depending on the species, exhibits ellipsoid, ovoid, and cylindrical shapes that sometimes taper at the posterior end. it can also exhibit more circular shapes in its vegetative non-motile cyst state. the cells are typically 7-12 μm in length, though there are few species larger or smaller than this"." "d. salina", for instance is larger in size, typically ranging from  16-24 μm. sizes of the cells vary with environmental conditions such as light, salinity, and nutrient availability .