Dog vomit slime mold

Appearance

Like many slime molds, the cells of this species typically aggregate to form a plasmodium, a multinucleate mass of undifferentiated cells that may move in an ameboid-like fashion during the search for nutrients. "F. septicas plasmodium may be anywhere from white to yellow-gray, typically 2.5–20 cm in diameter, and 1–3 cm thick. The plasmodium eventually transforms into a sponge-like aethalium, analogous to the spore-bearing fruiting body of a mushroom; which then degrades, darkening in color, and releases its dark-colored spores. "F. septica" produces the largest aethalium of any slime mold. This species is known to have its spores dispersed by beetles.

The spores have a two-layered wall, with a dense outer layer with spines, and a fibrous inner layer. During germination, the outer layer splits to create an opening, and more elastic inner layer ruptures later as protoplasm emerges. A remnant of the inner layer may be persistent and adhere to the protoplast after it has emerged from the spore. A peroxidase enzyme present in the inner cell wall plays a role in germination.

"Fuligo septica" grows on rotten wood and plant debris, but can also grow on the leaves and stems of living plants.

Habitat

Like many slime molds, the cells of this species typically aggregate to form a plasmodium, a multinucleate mass of undifferentiated cells that may move in an ameboid-like fashion during the search for nutrients. "F. septicas plasmodium may be anywhere from white to yellow-gray, typically 2.5–20 cm in diameter, and 1–3 cm thick. The plasmodium eventually transforms into a sponge-like aethalium, analogous to the spore-bearing fruiting body of a mushroom; which then degrades, darkening in color, and releases its dark-colored spores. "F. septica" produces the largest aethalium of any slime mold. This species is known to have its spores dispersed by beetles.

The spores have a two-layered wall, with a dense outer layer with spines, and a fibrous inner layer. During germination, the outer layer splits to create an opening, and more elastic inner layer ruptures later as protoplasm emerges. A remnant of the inner layer may be persistent and adhere to the protoplast after it has emerged from the spore. A peroxidase enzyme present in the inner cell wall plays a role in germination.

"Fuligo septica" grows on rotten wood and plant debris, but can also grow on the leaves and stems of living plants.

Defense

Slime molds have a high resistance to toxic levels of metals; one author was prompted to write "The levels of Zn in "Fuligo septica" were so high that it is difficult to understand how a living organism can tolerate them." The resistance to extreme levels of zinc appears to be unique to "F. septica". The mechanism of this metal resistance is now understood: "F. septica" produces a yellow pigment called fuligorubin A, which has been shown to chelate metals and convert them to inactive forms.

Evolution

The first description of the species was provided by French botanist Jean Marchant in 1727, who referred to it as "flowers of tan"; Marchant classified it as a "sponge". Carl Linnaeus called it "Mucor septicus" in his 1763 "Species Plantarum". The species was transferred to the genus "Fuligo" by German botanist Friedrich Heinrich Wiggers in 1780.

Cultural

In Scandinavian folklore, "Fuligo septica" is identified as the vomit of troll cats.

In Finland, "F. septica" was believed to be used by witches to spoil their neighbors' milk. This gives it the name "paranvoi", meaning "butter of the familiar spirit".