Microfauna

Microfauna (from Ancient Greek mikros 'small' and from Latin fauna 'animal') are microscopic animals and organisms that exhibit animal-like qualities and have body sizes that are usually <0.1mm.

They fill essential roles as decomposers and food sources for lower trophic levels, and are necessary to drive processes within larger organisms.

Populations of microfauna can reach up to ~107 (~10,000,000) individuals per g−1 (0.1g, or 1/10th of a gram) and are very common in plant litter, surface soils, and water films.

[6] The ecological functions of the rhizosphere can be influenced by microfauna, specifically by nematodes and protozoa, which are abundant in soil.

[citation needed] These organisms are often essential links in the food chain between primary producers and larger species.

For example, zooplankton are widespread microscopic animals and protists that feed on algae and detritus in the ocean, such as foraminifera.

Examples of notable phyla that include some microfauna: Macrofauna are organisms that are greater than 2mm in size that usually inhabit soft sediments.