[4][5] There is evidence that brownification of lakes in these areas, decreasing pH and higher water temperature initiated the spreading of this species.

[8] Like other heterokont algae, the planktonic cells of G. semen possess two differently shaped flagella,[9] which enable them to actively swim around in the water column.

Under physical stress, small organelles that sit under the cell membrane and are called trichocysts, explode and release slimy threads.

[12] Additionally, this species can grow in a wide range of pH and light conditions[13] allowing the frequent formation of blooms in summer.

Lack of efficient grazers in several lakes[10][14] and the ability to feed on dissolved organic matter[15] might further help G. semen to thrive in many different habitats.