Oospore
The zygotes (fertilized oogonia ) in algae and certain fungi are outdated as oospores (from the Greek oo = egg and spora = seeds) .
An oospore occurs when a female egg is fertilized by a male spermatozoid within the gametangium . The result is a zygote that significantly thickens its cell wall.
Oospores are not very sensitive to environmental fluctuations. They tolerate large temperature fluctuations and dehydration and are still capable of germination even after many years. The oospores of the algae sink to the bottom of the water or are drifted away. In this way, these can also be spread to relatively distant places and relocate there.