Picocystis

[2] Picocystis salinarum cells under normal conditions have a spherical or oval shape.

Under conditions of nutrient depletion they appear to form a trillobe shape.

This trillobe shape gives it the nickname Mickey Mouse, due to its appearance to the famous character's head.

The pigments are composed mainly from chlorophyll a and b and the carotenoids violaxanthin, alloxanthin, monadoxanthin, neoxanthin, lutein, diatoxanthin and zeaxanthin.

[3][4] The cell wall is mainly composed of polymers of the monosaccharide arabinose, polyarabinose.

Picocystis is one of the smallest green algae. Picocystis salinarum occurs in vast numbers in Mono Lake, where it is also referred to as Mickey Mouse (see bottom left).