|Sporangium of a Phycomyces sp.|
C. Moreau 1954
They are mostly found living in soil or on decaying plant or animal material. Some are parasites of plants, insects, and small animals. Others form symbiotic relationships with plants, where the plant and the fungi need each other to grow.
Zygomycete hyphae may be a syncytium, that is, having a mass of nuclei not divided into separate cells. On occasion these can be divided into separate parts by a cell wall called a septum. This only happens where gametes are formed, or to wall off dead hyphae.