Märkäpusteli

Märkäpusteli, commonly known as the slime mold *Fuligo septica*, is a fascinating and distinctive organism belonging to the group of plasmodial slime molds. It is widely recognized for its bright yellow to orange, gelatinous, and often cauliflower-like appearance when mature. This organism is not a fungus, plant, or animal, but rather a protist, which means it is a single-celled eukaryotic organism that can exhibit complex multicellular behavior during certain life stages.

The life cycle of märkäpusteli begins with haploid spores that germinate into flagellated cells called swarm cells. These cells fuse in pairs to form diploid zygotes, which then develop into a multinucleate plasmodium—a single cell with many nuclei. The plasmodium is typically colorless and moves by flowing over decaying organic matter, such as fallen leaves or wood, in search of nutrients. When environmental conditions become unfavorable, such as drought, the plasmodium transforms into a fruiting body, which is the recognizable yellow or orange structure.

Märkäpusteli is often found in temperate and tropical regions worldwide, thriving in moist, shaded environments. It plays a role in decomposition by breaking down organic material, contributing to nutrient cycling in ecosystems. While it is harmless to humans, its striking appearance has made it a subject of interest in both scientific and popular culture, often studied for its unique biological processes and behavior.

The organism’s common name, *märkäpusteli*, derives from Finnish, where *märkä* means "moist" and *pusteli* refers to its spore-producing structure. It is sometimes colloquially called "dog vomit slime mold" due to its appearance, though this name is not scientifically accurate. Researchers continue to explore its genetics, behavior, and ecological significance, making it a subject of ongoing biological study.