From oligo..., Greek sapros - rotten and bios - life).

Oligosaprobes are organisms living in slightly polluted water bodies, where organic matter is almost completely mineralized, very demanding to the amount of dissolved oxygen. Oligosaprobes may include larvae of mayflies, trout, minnows, Siberian minnows, and others.

Oligosaprobes are organisms living in clean water or water only slightly contaminated with organic matter. Such waters are dominated by oxidation processes due to excess dissolved oxygen. Nitrates are among the nitrogen compounds present; there is little carbon dioxide and no hydrogen sulfide. An oligosaprobic environment is an aquatic environment rich in dissolved oxygen and (relatively) free of decomposed organic matter.

Oligosaprobes include some green and diatom algae, flowering plants (e.g. European white water lilies), some rotifers, bryozoans, sponges, Dreissena molluscs, cladocerans (daphnids, bitotrephes), dragonfly and mayfly larvae, sterlet, trout, gudgeons and newts. Oligosaprobes also include several saprophytes, including bacteria (tens and hundreds per 1 cubic mm of water) and organisms that feed on bacteria. The term "oligosaprobes" is usually applied only to freshwater organisms.