Epigeic Earthworms
Epigeic is Greek for ‘upon the earth’ Epegeic earthworms are surface dwelling and scientifically classed along with all the other earthworms or oligochaeta of the annelida phylum.
Description
Epegeic Earthworms are small bodied ranging from 1-7 cm with some are bright red but most have reddish brown skin pigmentation. The pigment is darker on the back and lighter on the tail and the belly, which may provide extra protection from ultra violet rays that they are sensitive to. [1] (great lakes book) Epegeics share basically the same anatomy and reproduction methods as all the endgoic and anecic classified species.
Range, Habitat and Diet
They are adapted to the highly variable moisture and temperature conditions at the soil surface. The worms found in compost piles are epigeic and are unlikely to survive in the low organic matter environment of soil. [2](USDA) Epegeics inhabit all the continents except Anarctica, however they along with all other earthworms are invasive in the previously earth worm free temperate and boreal forests of North America. [3](Frelich et al., 2006).(GISD)The endoeic species can turn epigeic during suitable weather conditions but during dry weather retreat to the soil. Other epegeic go to soil to aestivate or hibernate. Some classify earthworms with these migrating resembling behaviors as epi-endogeic.
Example Species
Dendrobaena octaedra
Dendrobaena octaedra is a small (2-4 cm) epegeic. extensive morphological variability in its introduced North American range, and wide variability in somatic and reproductive characters in its native northern Europe range. [4](Terhivuo & Saura, 2006). Dendrobaena octaedra is common in coniferous forests in its native European and introduced North American range [5](Addison, 2009).
Eudrilus eugeniae
Eudrilus eugeniae is frequently used in vermicomposting of solid wastes other epegeic genera – Eisenia foetida and Perionyx excavatus are able to speed up the decomposition process of organic matter with especially under tropical conditions. [6](arjun Singh)
Lumbricus castaneus
Also known as the Chestnut worm. The species is endemic to England and most active in the spring months [7] (naturalist).
Eiseniella tetraedra
This red worm may vary from 2 to 8 cm in length. It is aquatic and can be found in mud or under stones in rivers, as well as in damp areas on land. It has a distinctive cliellum (saddle) around segments 20-25. They are widespread in Britain and found year round in gardens, fields, pastures, forests, estuary flats, lake shores, and in manure, often in damp conditions.[8]( nature Spot)
Roles in Soil
Benefits
Based on the feeding behavior of earthworms, epigeic species have a greater potential as waste decomposers, than anecics, and endogeics, which is due to their humus consuming and surface dwelling nature [6] (Arjun Singh). Epigeic species will feed primarily on microorganisms associated with decaying surface litter and facilitate the breakdown and mineralisation of surface litter [9] (Hendrix & Bohlen, 2002).These earthworms exert important effects on the presence of decomposer micro-organisms and their microbial grazers, which lead to changes in the rate of decomposition of the organic matter [10](FernandoMonroy) Nevertheless, little is known about whether and to what extent these changes are due to direct effects of earthworms on the decaying material (i.e. transformations of the ingested material during passage through the gut) or to indirect effects related to their casting and burrowing activities [11](Brown et al., 2000, Domínguez, 2004).
Problems
Epigeics physically disrupt the organic layer of the soil by consuming and mixing the F and H layers, producing a homogenous and granular form of organic forest floor [5] (Addison, 2009)
Exotic earthworms are a particular problem in previously earthworm-free temperate and boreal forests of North America dominated by Acer, Quercus, Betula, Pinus and Populus [3](Frelich et al., 2006).(GISD)
"harmful to forest floor" Although some can change fungi and macroinvertabrate populations but they do not decrease forest floor. [1] (great lakes book)
References
[1] Hale, Cindy. Earthworms of the Great Lakes. Kollath+Stensaas Pub., 2013.
[2] Edwards, Clive A. “Natural Resources Conservation Service.” Home | NRCS Soils, 2019, www.nrcs.usda.gov/wps/portal/nrcs/site/soils/home/.
[3] Frelich, Lee E., et al. “Earthworm Invasion into Previously Earthworm-Free Temperate and Boreal Forests.” Biological Invasions Belowground: Earthworms as Invasive Species, 2006, pp. 35–45., doi:10.1007/978-1-4020-5429-7_5.
[4] Terhivuo, Juhani, and Anssi Saura. “Dispersal and Clonal Diversity of North-European Parthenogenetic Earthworms.” Biological Invasions Belowground: Earthworms as Invasive Species, 2006, pp. 5–18., doi:10.1007/978-1-4020-5429-7_2.
[5] Addison, J.a., and S.b. Holmes. “Effect of Two Commercial Formulations of Bacillusthuringiensis Suhsp. Kurstaki on the Forest Earthworm Dendrobaenaoctaedra.” Canadian Journal of Forest Research, vol. 26, no. 9, 1996, pp. 1594–1601., doi:10.1139/x26-179.
[6] Singh, Arjun, et al. “Taxonomic and Functional Diversity of the Culturable Microbiomes of Epigeic Earthworms and Their Prospects in Agriculture.” Journal of Basic Microbiology, vol. 56, no. 9, 2016, pp. 1009–1020., doi:10.1002/jobm.201500779.
[7]“Chestnut Worm (Lumbricus Castaneus).” INaturalist.org, www.inaturalist.org/taxa/484186-Lumbricus-castaneus.
[8]“Eiseniella Tetraedra.” NatureSpot, 2019, www.naturespot.org.uk/species/eiseniella-tetraedra.
[9] Hendrix, Paul F., and Patrick J. Bohlen. “Exotic Earthworm Invasions in North America: Ecological and Policy Implications.” BioScience, vol. 52, no. 9, 2002, p. 801., doi:10.1641/0006-3568(2002)052[0801:eeiina]2.0.co;2.
[10] Monroy, Fernando, et al. “Changes in Density of Nematodes, Protozoa and Total Coliforms after Transit through the Gut of Four Epigeic Earthworms (Oligochaeta).” Applied Soil Ecology, vol. 39, no. 2, 2008, pp. 127–132., doi:10.1016/j.apsoil.2007.11.011.
[11]Domínguez, Jorge, and María Gómez-Brandón. “The Influence of Earthworms on Nutrient Dynamics during the Process of Vermicomposting.” Waste Management & Research, vol. 31, no. 8, 2013, pp. 859–868., doi:10.1177/0734242x13497079. http://jdguez.webs.uvigo.es/wp-content/uploads/2013/07/the-influence-of-earthworms-on-nutrient-dynamics.pdf
Epigeic earthworms Lumbricus castaneus, an epigeic earthworm Epigeic earthworms live on the surface of the soil in leaf litter. These species tend not to make burrows but live in and feed on the leaf litter. Epigeic earthworms are also often bright red or reddish-brown.
Epigeic earthworm speices include Dendrobaena octaedra, Dendrobaena attemsi, Dendrodrilus rubidus, Eiseniella tetraedra, Heliodrilus oculatus, Lumbricus rubellus, Lumbricus castaneus, Lumbricus festivus, Lumbricus friendi, Satchellius mammalis ( Earthworm society Britain)
Epegeic Earthworms are small bodied ranging from 1-7 cm with reddish brown skin pigmentation. The pigment is darker on the back and lighter on the tail and the belly, which may provide extra protection from ultra violet rays they are very sensitive to. Great lakes; Dendrobaena octaedra, Dendrobaena octaedra, Eiseniella tetraedra, Eiseniella eisneni. can change fungi and macroinvertabrate pops do not decrease forest floor. (great lakes book)
Dendrobaena octaedra is an epigeic species. It inhabits the litter layer, feeding primarily on microorganisms associated with decaying surface litter (Hale et al., 2008). Epigeic species facilitate the breakdown and mineralisation of surface litter (Hendrix & Bohlen, 2002).
Dendrobaena octaedra and Dendrodrilus rubidus are epigeic species, which inhabit and feed at the soil surface. Epigeics physically disrupt the organic layer of the soil by consuming and mixing the F and H layers, producing a homogenous and granular form of organic forest floor (Addison, 2009)
Exotic earthworms are a particular problem in previously earthworm-free temperate and boreal forests of North America dominated by Acer, Quercus, Betula, Pinus and Populus (Frelich et al., 2006).(GISD)
The endoeic species can turn epigeic during suitable weather conditions but during dry weather turn to soil and now called (epi-endogeic)
Other epegeic go to soil to aestivate or hibernate.
Based on the feeding behavior of earthworms, epigeic species have a greater potential as waste decomposers, than anecics, and endogeics, which is due to their humus consuming and surface dwelling nature. Although the epigeic earthworm species Eudrilus eugeniae is frequently used in vermicomposting of solid wastes other epegeic genera – Eisenia foetida and Perionyx excavatus are able to speed up the decomposition process of organic matter with especially under tropical conditions. (Taxonomic and functional diversity of the culturable microbiomes of epigeic earthworms and their prospects in agriculture Arjun Singh)
Epigeic earthworms (i.e. those that feed and live in the litter layer) increase decomposition rates and strongly affect populations of other litter inhabiting organisms (Domínguez et al., 2003, McLean and Parkinson, 2000a, McLean and Parkinson, 2000b). Nevertheless, little is known about whether and to what extent these changes are due to direct effects of earthworms on the decaying material (i.e. transformations of the ingested material during passage through the gut) or to indirect effects related to their casting and burrowing activities (Brown et al., 2000, Domínguez, 2004).
Epigeic earthworms are detritivorous organisms that live and feed in the soil litter layer. These earthworms exert important effects on the presence of decomposer micro-organisms and their microbial grazers, which lead to changes in the rate of decomposition of the organic matter(Changes in density of nematodes, protozoa and total coliforms after transit through the gut of four epigeic earthworms (Oligochaeta) Author links open overlay panelFernandoMonroy)