Eisenia

Eisenia is a genus of earthworms in the family Lumbricidae. Species in this genus are small to medium-sized and are primarily epigeic, living in the upper layers of decaying organic matter rather than deeper mineral soil. The best-known species are Eisenia fetida, commonly called the red wiggler, and Eisenia andrei; both have become widely used in composting systems and scientific study. Native to Europe, these worms have been introduced globally and are now common in home vermicomposting setups and commercial operations.

Eisenia species feed on decomposing plant material, bacteria, and fungi, and they tolerate high moisture and organic loading. They play a key role in breaking down kitchen scraps and garden waste, helping to aerate substrate and release nutrients. Reproduction is by hermaphroditic mating, producing cocoons that contain several developing embryos. Growth and reproduction are influenced by temperature, moisture, and food quality.

In addition to vermiculture, Eisenia fetida and related species are used in ecotoxicology and educational settings as model organisms for studies of soil biology and pollution effects. The genus includes several recognized species; taxonomic distinctions can be subtle and sometimes require morphological detail or genetic analysis.

See also: vermicomposting; earthworms; Lumbricidae.