"dunaliella" cells consist of a large, cup-shaped plastid that takes up the majority of the cell. its large pyrenoid, which sits in the centre of the chloroplast, is another defining feature that is the same in all "dunaliella" species. it is covered by a starch shell with numerous starch grains and pairs of thylakoids entering but not going completely through the pyrenoid exterior into its matrix. starch grains are also scattered all throughout the chloroplast. depending on how high the light intensities and salt concentrations are, the thylakoids can form stacks with up to ten units. within the thylakoid membranes, β-carotenoids can accumulate, especially in high salinity and light intensity conditions, in oil globules. the pigments are made of neutral lipids and give the green alga its orange to red to brown colouration. the accumulation of β-carotenoids serves to protect the cells in high light intensity environments by absorbing and dissipating excess light better than chlorophyll can. in milder conditions, chlorophyll pigments make the cells look yellow to green. the chloroplast of "dunaliella" also has an eyespot that sits at an anterior peripheral position and is made of one to two rows of lipids.