Which fungal groups commonly have coenocytic hyphae

Coenocytic hyphae are hyphae without cross-walls or septa, meaning their cytoplasm is continuous and contains many nuclei. This structure is mainly found in primitive fungal groups like Zygomycota (for example, Rhizopus, the black bread mold) and Chytridiomycota. 

Some members of Oomycota, which are fungus-like organisms, also exhibit coenocytic hyphae. Because these hyphae lack internal partitions, the cytoplasm and nutrients flow freely along the length of the filament. 

This continuous structure allows rapid growth and quick repair if parts of the hypha are damaged. However, the absence of septa also means any local injury can affect the whole filament. Overall, coenocytic hyphae are a key adaptation for fast-growing, saprophytic fungi that thrive in nutrient-rich environments such as decaying organic matter or soil.