noun retÂ·roÂ·gresÂ·sion \Ëre-trÉ-Ëgresh-Én\. : a reversal in development or condition: asa: return to a former and less complex level of development or organizationb: subsidence or decline of symptoms or manifestations of a disease.
Habitat. Slime molds live in somewhat variable habitats all over the world. Generally slime molds live in damp areas of vegetation. They live under rotting logs and damp leaves. Some of the other habitats that slime molds will inhabit include water such as tropical fish tanks.
A third group, the Labyrinthulomycota or slime nets, are also called slime molds, but appear to be more closely related to the Chromista, and not relatives of the other slime mold groups. What these three groups have in common is a life cycle that superficially resembles that of the fungi. When conditions become unfavorable, these slime molds form sporangia-clusters of spores, often on the tips of stalks such as in the sporangium of a Physarum shown at right.