Zygospores are the diploid reproduction stage in the life cycle of many fungi and protists. Zygospores are produced by the nuclear fusion of haploid cells. In fungi, zygospores are formed after special germination structures are fused, come from the same mycelium or from different fungi, and can be thick spores. In many eukaryotic algae, including many species of chlorophyll, zygospores are formed by the fusion of single-cell gametes of different mating types. Zygospores are dormant, waiting for environmental cues, such as light, moisture, heat, or chemicals secreted by plants. When the environment is favourable, the conjugative spores germinate, undergo meiosis, and release haploid vegetative cells. In fungi, sporangia produce sporangia at the end of the sporophyte, and the sporangia shed spores. The fungi that form zygospores are called zygomycetes, indicating that this species is characterized by this evolutionary development.