Slime molds are organisms in two taxonomic groups, the cellular slime molds (Phylum Acrasiomycota) and the plasmodial slime molds (Phylum Myxomycota). Organisms in both groups are eukaryotic (meaning that their cells have nuclei) and are fungus-like in appearance during part of their life cycle. For this reason, they were traditionally included in mycology textbooks. However, modern biologists consider both groups to be only distantly related to the fungi. The two groups of slime molds are considered separately below.

Species in the cellular slime mold group are microscopic during most stages of their life cycle, when they exist as haploid (having one copy of each chromosome in the nucleus), single-celled amoebas. The amoebas typically feed on bacteria by engulfing them, in a process known as phagocytosis, and they reproduce by mitosis and fission. Sexual reproduction occurs but is uncommon. Most of what we know about this group...