When the mycelium of one fungus encounters another fungus of the same species and a complementary mating type, it can start to produce compounds to interact with the new fungus. Through a series of chemical exchanges, the two fungi each begin to extend toward each other. When they touch, they wall off an area of that extension by creating a septum. This area, filled with haploid nuclei, is called a gametangium .Coenogametangia means gamete with multi nucleus. The walls between the gametangia of each fungus dissolve and the two fungi combine cytoplasm (plasmogamy) and then fuse the nuclei together (karyogamy) to form many diploid nuclei.
Zygospore is produced by the fusion of two gametangia and is black in colour.
It has a thick wall to protect it from environmental conditions.
It contains a high amount of fat globules for developing zygospore. Lately, zygospore germinates undergoing meiosis.