There is no jacket of sterile cells protecting the gametes. Release of algal sperm cells from a single cell Moss egg cell surrounded by sterile cells Being aquatic, algae are marine freshwater terrestrial Terrestrial algae are effectively surviving in an aquatic environment on land. Soil algae survive in a film of soil water. The other major group of terrestrial algae are those in lichen symbioses. Lichens comprise algae and fungi in partnership.
Lichens are very good sensors of environmental pollution .
Crustose lichen on rock Fruticose lichen As terrestrial plants the algae have a unique role as pioneer plants. They grow on bare rock, providing there is moisture. The rock weathers and crumbles. The algae die. The mineral contribution of the rock and the organic remains of the algae lead to formation of soil.