Polysaprobe

an organism that inhabits waters greatly contaminated with organic matter, that is, rivers and closed bodies of water into which household and industrial organic wastes are released. The medium inhabited by polysaprobes contains substantial amounts of proteins, polypeptides, and carbohydrates. There is a deficiency of oxygen and an accumulation of carbon dioxide gas, hydrogen sulfide, and methane. The succession of communities of organisms in such waters is often catastrophically rapid. The growths formed by polysaprobes are slimy or flocculent.

Typical polysaprobes include the bacteria Zoogloea ramigera and Beggiatoa alba, the flagellate Oicomonas mutabilis, and the infusorians Paramaecium putrinum and Vorticella microstoma. Facultative polysaprobes include the bacteria Sphaerotilus natans, the green alga Polytoma uvella, the worm Tubifex tubifex, and the larva of the fly Eristalis tenax (the only polysaprobic insect).

Polysaprobes are distinguished by a lack of diversity in species composition. However, those species that have been able to adapt to the harmful environmental conditions are represented by a large number of individuals. Among polysaprobes there are many saprophytes, including bacteria and the organisms that feed upon them. Polysaprobes are very important in the life of a body of water, since they decompose organic substances and biologically purify sewage.