Fruiting Bodies are absent in Phycomycetes because:-
1.Phycomycetes are primitive form of fungi whereas fruiting bodies is an advance feature which only exist in fungi like Ascomycetes, Basidiomycetes etc.
2.Moreover Phycomycetes resemble more of algae than fungi.
3. The mycelium of Phycomycetes is aseptate and coenocytic whereas the mycelium of all fruiting bodies is septate. But in some cases Zygospores are called as the fruiting bodies of Phycomycetes.