slime mold plasmodium

Description:

Slime mold plasmodium with the first frost of the year. Slime mold is a broad term describing some organisms that use spores to reproduce. Slime molds were formerly classified as fungi or protists, but are no longer considered part of these kingdoms. Their common name refers to part of some of these organisms' life cycles where they can appear as gelatinous "slime". This is mostly seen with the myxomycetes, which are the only macroscopic slime molds. They feed on microorganisms that live in any type of dead plant material and contribute to the decomposition of dead vegetation, and feed on bacteria, yeasts, and fungi. Slime molds begin life as amoeba-like cells. These unicellular amoebae multiply if they encounter their favorite food, bacteria. These amoebae can mate if they encounter the correct mating type and form zygotes which then grow into plasmodia. These contain many nuclei without cell membranes between them, which can grow to be meters in size. The amoebae and the plasmodia engulf microorganisms. The plasmodium grows into an interconnected network of protoplasmic strands. Within each protoplasmic strand the cytoplasmic contents rapidly stream.The streaming protoplasm within a plasmodial strand can reach speeds of up to 1.35 mm per second. Migration of the plasmodium is accomplished when more protoplasm streams to advancing areas and protoplasm is withdrawn from rear areas. When the food supply wanes, the plasmodium will migrate to the surface of its substrate and transform into rigid fruiting bodies. The fruiting bodies or sporangia are what we commonly see; they superficially look like fungi or molds but are not related to the true fungi. These sporangia will then release spores which hatch into amoebae to begin the life cycle again.