Microcystis flos-aquae (Cyanobacteria, Chroococcales) is a together with Microcystis aeruginosa are common in Lake Kinneret throughout the year, occasionally forming blooms with surface scums in winter or spring. The individual cells in a M. flos-aquae colony are 3-4 um in diameter, the colony is spherical or lens-shaped, with varying degree of spacing between cells within a colony. The dark spots clearly showing in the individual cells in this picture are due to the reflection of light from the gas vesicles. A bunch of choanoflagellates are attached at the upper left side of the colony.