Slime Mold is a broad term referring to amoeba-like organisms, hence the name slime, which feed on microorganisms in decaying vegetable matter, hence the name molds. They can be found in the soil, on lawns, and in the forest commonly on deciduous logs. They are also common on mulch or even in the leaf mold in gutters.
Within each protoplasmic strand the cytoplasmic contents rapidly stream. If one strand is carefully watched for about 50 seconds the cytoplasm can be seen to slow, stop, and then reverse direction. The streaming protoplasm within a plasmodial strand can reach speeds of up to 1.35 mm per second which is the fastest rate recorded for any organism (Alexopoulos, 1962). Migration of the plasmodium is accomplished when more protoplasm streams to advancing areas and protoplasm is withdrawn from rear areas.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, superficially look like fungi or molds but they are not related to the true fungi. These sporangia will then release spores which hatch into amoebae to begin the life cycle again (Ling, 1999).
Most slime mold are smaller than a few centimeters, but the very largest reach areas of up to thirty square meters, making them the largest undivided cells known. Many have striking colors such as yellow, brown and white.
Slime molds can generally be divided into two main groups. A plasmodial slime mold involves numerous individual cells attached to each other, forming one large membrane. This "supercell" is essentially a bag of cytoplasm containing thousands of individual nuclei. By contrast, cellular slime molds spend most of their lives as individual unicellular protists, but when a chemical signal is secreted, they assemble into a cluster that acts as one organism.
A common slime mold which forms tiny brown tufts on rotting logs is Stemonitis. Another form which lives in rotting logs and is often used in research is Physarum polycephalum. In logs it has the appearance of a slimy webwork of yellow threads, up to a few feet in size. Fuligo forms yellow crusts in mulch.
The Protostelids' life cycle is very similar to the above descriptions, but they are much smaller, the fruiting bodies only forming one to a few spores.
The Dictyosteliida, cellular slime molds, are distantly related to the plasmodial slime molds and have a very different life style. Their amoebae do not form huge coenocytes, and remain individual. They live in similar habitats and feed on microorganisms. When food runs out and they are ready to form sporangia, they do something radically different. They release signal molecules into their environment, by which they find each other and create swarms. These amoeba then join up into a tiny multicellular slug-like coordinated creature, which crawls to an open lit place and grows into a fruiting body. Some of the amoebae become spores to begin the next generation, but some of the amoebae sacrifice themselves to become a dead stalk, lifting the spores up into the air.
The Acrasidae have a life style similar to Dictyostelids, but their amoebae behave differently and are of uncertain taxonomic position.
Researchers Submit Patent Application, "Path Finding System, Computer, Control Method, and Program", for Approval
Jul 25, 2013; By a News Reporter-Staff News Editor at Politics & Government Week -- From Washington, D.C., VerticalNews journalists report that...
New Phosphotransferases (Alcohol Group Acceptor) Study Findings Have Been Reported from Northeast Normal University.
Apr 12, 2011; Investigators publish new data in the report 'Identification of a novel PSR as the substrate of an SR protein kinase in the true...