What Is the Classification for Earthworms?

Earthworms range in size from a few millimeters to over 3 feet.

There are over 1800 species of earthworms grouped into five families worldwide. Earthworms break down dead, decomposing organic matter and function as a significant element of the soil ecosystem.

Classification

According to the University of Florida IFAS Extension website, earthworms are classified as belonging to the order Oligochaeta, class Chaetopoda and phylum Annelida. Most worms found in North America, Europe and Western Asia belong to the Lumbricidae family, which consists of around 220 species.

Types

Earthworms are classified into three types. Litter dwellers, such as redworms, belong to the epigeic species and live in crop or forest debris. Topsoil dwellers (the endogeic species) live in the upper 2 to 3 inches of soil and creat horizontal burrows. Subsoil dwellers, such as nighcrawlers, belong to the anecic species and they live 5 to 6 feet down in the soil in vertical burrows.

Identification

The body of an earthworm is composed of many segments or rings and each segment performs a function. Sections include the head, nervous, muscular, circulatory, digestive, excretory and reproductive systems.

Benefits

Earthworms play an essential function in maintaining the productivity of soils. These include consuming and recycling organic matter, soil drainage, root growth and increasing the water-holding capacity of soils.

References

• University of Florida IFAS Extension: Earthworm Biology
• Penn State College of Agricultural Sciences: Earthworms
• United States Department of Agriculture: The Living Soil: Earthworms

Resources

• University of California: Earthworm Information