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Lumbricus

Lumbricus is a genus of terrestrial earthworms belonging to the family Lumbricidae within the phylum Annelida, first described by Carl Linnaeus in 1758 with Lumbricus terrestris as the type species.^[1] The genus is monophyletic and comprises 18 recognized species, distinguished by morphological traits such as a tanylobous prostomium, reddish-purple body pigmentation, paired chaetae, and seminal vesicles located in segments 9, 11, and 12.^[2] Native to temperate regions of Europe—particularly France and the Central European Alpine area—these soft-bodied, segmented oligochaetes have become widely distributed through human activities, with species like L. terrestris (the common nightcrawler) and L. rubellus (the red marsh worm) establishing invasive populations in North America, New Zealand, and parts of Asia.^[2]^[1] Members of Lumbricus play pivotal ecological roles in soil ecosystems; earthworms of the family Lumbricidae, including Lumbricus, often comprise up to 90% of invertebrate biomass in temperate soils where present, and they enhance soil structure through bioturbation, facilitate nutrient cycling by processing organic matter, and influence plant community dynamics.^[3] Species exhibit varied functional groups, including epigeic forms that inhabit surface litter layers as detritivores and epi-anecic burrowers that construct semi-permanent vertical tunnels extending up to 2 meters deep, emerging nocturnally to feed.^[2] Body sizes range from small species like L. castaneus at 3–6 cm to larger ones such as L. badensis exceeding 30 cm in length, with all species being hermaphroditic and capable of cross-fertilization during mating.^[2] Phylogenetic analyses reveal that the genus evolved from small epigeic ancestors, with three independent origins of invasive lineages contributing to its global success.^[2]

Taxonomy

Classification

The genus Lumbricus is classified within the kingdom Animalia, phylum Annelida, class Clitellata, order Opisthopora, suborder Crassiclitellata, superfamily Lumbricoidea, family Lumbricidae.^[1] This placement situates Lumbricus among the terrestrial oligochaete earthworms, distinguished from aquatic or marine annelids by adaptations to soil environments.^[4] Phylogenetically, Lumbricus forms a monophyletic clade within the family Lumbricidae, which comprises over 300 species of temperate-zone earthworms.^[2] The genus shares close evolutionary ties with other lumbricid genera such as Aporrectodea, Eisenia, and Bimastos, based on multilocus analyses of mitochondrial and nuclear DNA sequences that resolve Lumbricidae into 11 major clades.^[3] Within Lumbricus, species cluster into distinct groups, including an early-branching lineage represented by L. baicalensis and later-diverging clades containing common species like Lumbricus terrestris.^[2] The evolutionary history of Lumbricus traces back to ancient annelids, with the suborder Lumbricina (encompassing Lumbricidae) diverging from other annelid lineages around 200 million years ago during the Late Triassic to Early Jurassic.^[5] The family Lumbricidae itself originated in the Holarctic region during the Lower Cretaceous approximately 125 million years ago, with subsequent diversification driven by tectonic events and glaciation that shaped temperate soil ecosystems.^[3] This timeline aligns with fossil evidence of clitellate annelids and molecular clock estimates calibrated against polychaete divergences.^[6] Key diagnostic traits for identifying the genus Lumbricus include the presence of a well-developed clitellum, a glandular band typically spanning 6 segments (e.g., segments 26½–33½ in many species), eight setae per segment arranged in closely paired positions (lumbricine pattern), and prominent tubercula pubertatis—raised glandular swellings on the clitellum used in reproduction, often positioned ventrolaterally across 3–4 segments (e.g., 28–31 in L. rubellus).^[7] These features, combined with male pores on segment 15 and no intestinal caeca, distinguish Lumbricus from related genera like Aporrectodea, which may lack certain tubercula configurations or exhibit different setal spacing.^[2]

Etymology

The genus name Lumbricus derives from the Latin noun lumbricus (genitive lumbrīcī), meaning "worm," with classical usage primarily denoting an intestinal worm or similar parasite.^[8] This term was adopted in scientific nomenclature by Carl Linnaeus in 1758, when he established Lumbricus as the genus for earthworms in the 10th edition of Systema Naturae, marking one of the earliest binomial names for such organisms.^[9] The word lumbricus has deep historical roots in ancient Roman literature, where it served as a vernacular term for various worm-like creatures, including those in the human body, as referenced in works by authors like Pliny the Elder.^[10] Pliny, in his Naturalis Historia (circa 77 CE), described earthworms for their medicinal properties in treating wounds but did not explicitly apply lumbricus to them, reflecting the term's initial focus on parasitic forms rather than soil-dwelling annelids.^[11] Over time, lumbricus evolved in usage to encompass earthworms specifically, aligning with its adoption in Linnaean taxonomy as part of the emerging binomial system for classifying invertebrates. In contrast to the formal genus name, vernacular terms like "nightcrawler" apply to particular species such as Lumbricus terrestris, highlighting regional common names that differentiate these earthworms from other worms without reference to the Latin etymology.^[1]

Diversity and Species

The genus Lumbricus encompasses 13 valid extant species, primarily native to Europe, with several widely distributed through human-mediated introductions. These species are distinguished primarily through morphological and genetic analyses, as outlined in taxonomic databases. Key examples include Lumbricus terrestris Linnaeus, 1758 (nightcrawler or dew worm), a large anecic species known for deep burrowing; Lumbricus rubellus Hoffmeister, 1843 (red marshworm), an epigeic species with reddish pigmentation; Lumbricus castaneus (Savigny, 1826) (chestnut worm), featuring a chestnut-brown hue; Lumbricus festivus (Savigny, 1826) (Quebec worm); Lumbricus friendi Cognetti, 1904; Lumbricus centralis Bouché, 1972; Lumbricus badensis Michaelsen, 1907; Lumbricus baicalensis Michaelsen, 1900; Lumbricus herculeus (Savigny, 1826); Lumbricus improvisus Zicsi, 1963; Lumbricus klarae Zicsi & Csuzdi, 1999; Lumbricus meliboeus Rosa, 1884; and Lumbricus polyphemus Fitzinger, 1833.^[1] Morphological variations among Lumbricus species include differences in body pigmentation, such as the uniform reddish-brown of L. rubellus versus the darker, iridescent dorsum of L. terrestris, and segment counts that typically range from 95 to 170, with L. rubellus often exhibiting 95–120 segments and L. terrestris 120–170. Genetic distinctions are evident in cryptic lineages within species like L. rubellus and L. terrestris, identified through mitochondrial DNA barcoding, which reveal divergent clades without clear morphological correlates but influence ecological roles. These traits aid in species delineation, particularly in sympatric populations.^[9]^[12]^[13] Regarding conservation, most Lumbricus species are not formally assessed by the IUCN and are regarded as least concern in their native Palearctic distributions due to their abundance and adaptability. However, species such as L. terrestris and L. rubellus exhibit invasive potential outside Europe, particularly in North American forests, where they alter soil structure, nutrient cycling, and understory vegetation, prompting management concerns in invaded ecosystems.^[14]^[15]^[12]

Description

Morphology

Lumbricus species exhibit a classic annelid body plan characterized by a long, cylindrical, and externally segmented form consisting of numerous metameres, typically numbering 120 to 180 in L. terrestris.^[9] The anterior end features a prostomium, a non-segmented, tanylobous, lobed structure that serves as a sensory and feeding appendage, while the posterior terminates in a simple pygidium bearing the anus.^[16]^[2] Internally, these worms are coelomates, with a spacious coelom divided into segmental compartments by transverse septa and longitudinal mesenteries, providing hydrostatic support and facilitating organ arrangement.^[9] Key anatomical features include chitinous setae, with eight per segment arranged in four pairs, embedded in the body wall to enable grip and movement.^[16] Excretion is managed by paired metanephridia, one in each segment from the fourth onward, which filter coelomic fluid and expel waste through nephridiopores.^[9] The circulatory system comprises a closed network dominated by a dorsal blood vessel that pulses anteriorly and a ventral vessel that carries blood posteriorly, interconnected by lateral segmental vessels and five pairs of aortic arches functioning as hearts.^[16] Sensory capabilities in Lumbricus rely on simple structures rather than complex organs, with unicellular photoreceptors concentrated on the prostomium for light detection and chemoreceptors distributed across the body surface for chemical sensing.^[16] These worms lack eyes or other specialized visual organs, and their nervous system consists primarily of a ventral nerve cord running the length of the body, featuring segmental ganglia for localized coordination and connected anteriorly to cerebral ganglia.^[9]

Size and Coloration

Adult individuals of the genus Lumbricus range in size from 3–6 cm in smaller species such as L. castaneus to over 30 cm in larger ones like L. badensis (up to 34 cm), with typical adults of common species measuring 10-30 cm in length and 0.5-1 cm in diameter, and weights ranging from less than 1 g to around 5 g or more.^[2] For instance, Lumbricus terrestris, one of the largest species, averages 11-20 cm in length and 7-10 mm in diameter, while Lumbricus rubellus is smaller, reaching 6-15 cm in length and 4-6 mm in width.^[17]^[18]^[14] The external coloration of Lumbricus species is characterized by dark reddish-brown to reddish-purple hues on the dorsal surface, attributed to the visibility of hemoglobin-rich blood through the thin, translucent skin, with the ventral side appearing paler.^[19]^[20]^[2] Species-specific variations exist; L. terrestris exhibits a more uniform pinkish to reddish-brown tone that fades slightly toward the posterior, whereas L. rubellus displays a purplish-reddish-brown dorsum with an iridescent sheen.^[14]^[17]^[18] Growth in Lumbricus is influenced by environmental nutrition, with nutrient-rich diets promoting larger body sizes and faster maturation; for example, L. terrestris achieves higher mass when fed organic matter like horse manure compared to leaf litter.^[21]^[22] As simultaneous hermaphrodites, these earthworms exhibit no sexual dimorphism in size or coloration, though pigmentation may intensify dorsally with age, becoming darkest at the anterior end in mature individuals.^[23]^[2]

Habitat and Distribution

Environmental Preferences

Lumbricus species thrive in moist, loamy soils rich in organic matter, which provide the necessary aeration, nutrients, and structure for burrowing and feeding.^[24] These earthworms prefer soils with a pH range of 5 to 8, though some species like L. terrestris can tolerate lower pH values down to 3.5–3.7, while L. rubellus accommodates pH as low as 3.0 and up to 7.7.^[25]^[14]^[12] They avoid waterlogged conditions that limit oxygen availability and compacted soils that hinder movement, favoring instead well-drained topsoils with ample humus.^[24] Climatically, Lumbricus exhibit optimal activity and growth between 10°C and 25°C, with peak performance often at 15–20°C for processes like casting and juvenile development.^[26]^[27] In extreme cold below 0°C, species such as L. terrestris enter hibernation by retreating to deeper soil layers to evade frost, as they lack frost tolerance.^[14] During intense heat or drought exceeding 25–30°C, they may aestivate in protective cocoons or burrows to conserve moisture and survive unfavorable periods.^[28] Moisture levels around 20–30% of soil water-holding capacity are ideal, supporting respiration and preventing desiccation.^[26] Microhabitat selection varies by ecological group within the genus; epigeic species like L. rubellus predominantly occupy the upper soil layers (0–30 cm), where organic litter is abundant and surface access facilitates feeding on decaying plant material.^[12] Anecic species such as L. terrestris, while capable of deeper burrows, often remain active in the top 20–30 cm during favorable conditions to retrieve surface litter.^[14] This preference for superficial zones enhances their role in soil aeration while aligning with their need for consistent moisture and moderate temperatures.^[24]

Global Range

The genus Lumbricus is native primarily to Europe, with its ancestral range centered in Western and Central Europe, including regions such as France, the Netherlands, Austria, Germany, and surrounding areas.^[2] Species like L. terrestris are widespread across temperate zones of the continent, extending from the United Kingdom in the west to Russia in the east.^[9] The family Lumbricidae, to which Lumbricus belongs, has origins that also encompass western Asia, contributing to the genus's historical presence in Eurasian temperate habitats.^[29] Through human-mediated dispersal, Lumbricus species have been introduced to numerous regions outside their native range, particularly via agricultural practices, soil transport, and potted plants since the 1600s.^[15] In North America, European settlers intentionally and accidentally brought species such as L. terrestris and L. rubellus along the east coast around 400 years ago, leading to their spread across northern forests east of the Rocky Mountains and into parts of Canada and the Pacific coast.^[15] These introductions have established Lumbricus in over 50 countries worldwide, often in temperate to mild boreal climates suitable for their burrowing lifestyle.^[30] Introduced populations of Lumbricus have also reached Australasia, including New Zealand, where lumbricid species were surveyed across farms and established through deliberate agricultural enhancements.^[9] In parts of South America, such as Colombia, L. rubellus has invaded local ecosystems, reflecting broader patterns of transoceanic spread.^[9] In many non-native areas, particularly North American forests, Lumbricus species exhibit invasive characteristics, altering soil structures and outcompeting local biota through rapid colonization facilitated by human activities like fishing bait distribution.^[15]

Ecology and Behavior

Locomotion and Burrowing

Lumbricus species exhibit peristaltic locomotion, characterized by alternating waves of contraction in their circular and longitudinal muscles that propagate from the anterior to posterior end of the body, enabling forward movement through soil.^[31] This process involves the circular muscles contracting to elongate segments while the longitudinal muscles shorten them, creating a rhythmic undulation that propels the worm.^[32] Setae, bristle-like structures embedded in the body wall, extend to provide traction against the soil substrate during these contractions, preventing backward slippage.^[33] Burrowing in Lumbricus varies by ecological type, with anecic species such as Lumbricus terrestris constructing semi-permanent vertical tunnels that can extend up to 2 meters deep, facilitating access to surface litter and deeper soil layers.^[34] These worms reuse and maintain these burrows through repeated passages, often lining them with mucus for stability. In contrast, epigeic Lumbricus species, like Lumbricus rubellus, form extensive horizontal galleries in the upper soil horizons and litter layers, creating a network of shallower channels for subsurface navigation.^[35] Lumbricus worms display a diurnal rhythm in activity, with surface foraging and casting occurring primarily at night when humidity is higher, while they retreat to subsurface burrows during the day to minimize desiccation risk.^[36] This pattern positions individuals closest to the soil surface around midnight and deepest at noon, aligning with environmental moisture gradients.

Feeding and Digestion

Lumbricus species, such as L. terrestris, primarily consume organic detritus including decaying plant matter, leaf litter, and root fragments, along with associated soil microbes, through non-selective ingestion of soil and surface litter.^[37]^[38] These earthworms ingest substantial quantities of soil, typically ranging from 0.2 to 6.7 grams of dry soil per gram of earthworm body weight per day, allowing them to process up to their own body weight or more in material daily depending on environmental conditions and food availability.^[39] This feeding strategy enables them to extract nutrients from low-quality organic substrates while translocating soil particles through their gut. The digestive system of Lumbricus is a straight tubular alimentary canal extending from the mouth to the anus, adapted for processing ingested soil and organic matter. Food enters via the mouth and is drawn into the muscular pharynx, which secretes mucus to facilitate ingestion and initial lubrication.^[40] The pharynx connects to the esophagus, a narrow tube that includes calciferous glands—paired structures in species like L. terrestris that secrete calcium carbonate to neutralize acidity in the ingested material and regulate gut pH.^[16]^[41] Posterior to the esophagus lie the crop for temporary storage and the gizzard, which grinds the material using ingested soil particles as an abrasive. The lengthy intestine, comprising the majority of the gut, features a typhlosole fold that increases surface area for enzymatic digestion and nutrient absorption, primarily of simple sugars, amino acids, and microbial biomass. Undigested residues, including mineral particles and refractory organics, are compacted and expelled through the anus as casts.^[40]^[16] Digestion in Lumbricus is relatively inefficient in terms of organic matter assimilation, with estimates indicating that assimilation efficiencies vary from 20% to 50% of the ingested organic material depending on the substrate quality, the remainder being egested in casts enriched with microbial byproducts.^[42] This low assimilation rate is offset by the high volume of intake and the role of gut symbionts, including bacteria and fungi, which enhance breakdown of complex compounds like lignin through enzymatic activity.^[43] These microbial communities, enriched in the anoxic gut environment, contribute to lignocellulose degradation, enabling Lumbricus to access nutrients from otherwise recalcitrant plant residues.^[44]^[45]

Interactions with Other Organisms

Lumbricus species, such as L. terrestris, serve as prey for a variety of predators, including birds like robins that forage for surfaced worms, mammals such as moles that hunt underground, and reptiles including snakes that consume them in soil habitats.^[46]^[25]^[47]^[48]^[49] In response to predation, Lumbricus earthworms exhibit anti-predator adaptations, notably their capacity for regeneration, which has evolved under predatory pressure to allow recovery from partial consumption by restoring lost segments through epimorphic processes involving blastema formation.^[50] Lumbricus engages in mutualistic symbioses with soil microbes, particularly gut-associated bacteria that aid in the decomposition of organic matter by enhancing nutrient cycling and enzyme production during digestion.^[51]^[52]^[53] Parasitic interactions include infestation by nematodes, such as larval forms inhabiting the coelom of L. terrestris and species like Rhabditis terricola targeting earthworm cocoons, which can reduce host fitness by competing for resources and impairing reproduction.^[54]^[55] In invaded habitats, Lumbricus species face competition with other earthworm genera, notably Aporrectodea caliginosa, for food resources and burrowing space, where interspecific interactions often suppress growth rates more than intraspecific ones due to overlapping ecological niches.^[56]^[57]

Reproduction and Life Cycle

Mating Behaviors

Lumbricus species, including the common L. terrestris, are simultaneous hermaphrodites capable of mutual insemination during copulation, where each individual acts as both male and female, exchanging sperm reciprocally to fertilize the partner's eggs.^[58] This cross-fertilization occurs exclusively through outcrossing with a partner, as self-fertilization is mechanically impossible despite the presence of both reproductive organs, ensuring genetic diversity in populations.^[23] Courtship in Lumbricus terrestris typically begins with individuals emerging onto the soil surface on cool, moist nights, particularly following rain, to increase encounters with potential mates.^[59] Pairs engage in precopulatory rituals involving repeated mutual visits to each other's burrows, where they follow mucus trails left by the partner and exchange mucus secretions that facilitate attraction and assessment of mate quality.^[60] These interactions, lasting up to 90 minutes, often include gentle touches and assessments of body size, with a preference for similarly sized partners to minimize risks during mating.^[59] During copulation, which lasts 1 to 3 hours (median around 2 hours), the worms align in a head-to-tail position on the surface, with their genital pores (located in segment 15) positioned opposite the partner's clitellum for sperm transfer along a seminal groove formed by mucus.^[59] They remain partially anchored in their burrows for safety, enveloped in a shared slime tube produced by epidermal glands, while copulatory setae pierce the partner's skin to aid in attachment and possibly enhance sperm uptake.^[61] This process promotes genetic mixing, as outcrossing avoids inbreeding depression observed in related species, thereby supporting population viability.^[58]

Development Stages

The development of Lumbricus species commences with the production of egg cocoons following mating. Each cocoon, secreted by the clitellum and deposited in the soil, typically contains 1 to 20 eggs, with the exact number varying by species and environmental conditions.^[62] These leathery cocoons protect the eggs during incubation, a process influenced primarily by soil temperature and moisture; under optimal conditions (10–20°C), hatching occurs in 3 to 12 weeks, though lower temperatures can extend this period up to several months.^[63] Upon hatching, juvenile Lumbricus emerge at a length of approximately 1–2 cm, lacking a fully developed clitellum and possessing translucent, pale bodies.^[64] These juveniles feed on organic matter in the soil and undergo rapid initial growth by continuously adding segments and expanding in size. Maturation to sexual maturity generally takes 1–2 years, marked by the formation of the clitellum around segments 26–32, which enables reproduction; this timeline can accelerate in warmer conditions, with clitellum development observed as early as 9–26 weeks post-hatching depending on temperature.^[65] In the wild, Lumbricus individuals typically live 4–8 years, though survival rates are heavily impacted by biotic factors such as predation from birds, mammals, and invertebrates, as well as abiotic stresses like drought and soil compaction.^[66] Predation, in particular, significantly reduces average lifespan, with many juveniles and young adults succumbing before reaching full maturity.^[67]

Human Relevance

Agricultural Impact

Lumbricus species, particularly Lumbricus terrestris, contribute positively to agricultural systems by enhancing soil aeration through their deep burrowing activities, which create permanent vertical channels up to 5-6 feet in depth that facilitate oxygen exchange for plant roots and soil microbes.^[68] These burrows also significantly improve water infiltration, with soils containing earthworms exhibiting up to six times greater infiltration rates in zero-tillage systems compared to those without, reducing runoff and erosion risks in farmed fields.^[69] In addition, Lumbricus earthworms promote nutrient cycling by processing organic matter and producing nutrient-rich castings that elevate soil fertility; for instance, their casts contain higher concentrations of available nitrogen, phosphorus, potassium, and calcium than surrounding soil, processing up to 2 tons of dry matter per acre annually and accelerating the mineralization of soil organic matter.^[68]^[70] This feeding and casting behavior, which involves consuming surface litter and soil, enhances overall plant nutrient availability and supports crop growth in diverse agricultural settings.^[53] Despite these advantages, high densities of Lumbricus earthworms can lead to drawbacks, such as occasional crop damage through root feeding or burrowing that disrupts seedling establishment, particularly in dense populations exceeding optimal levels for soil health.^[53] In wet soils prone to waterlogging, earthworm activity may inadvertently promote the spread of certain plant pathogens by altering soil moisture dynamics and microbial communities, potentially exacerbating disease incidence in susceptible crops like vegetables.^[53] Farmers manage Lumbricus populations effectively through vermicomposting, where species like Lumbricus rubellus are utilized to convert organic wastes into stable, nutrient-dense compost that boosts soil fertility when applied to fields, reducing reliance on synthetic fertilizers.^[71] This practice integrates well with sustainable agriculture, as Lumbricus earthworms have historically supported European farming since medieval times by naturally tilling and enriching soils in traditional plow-based systems, predating modern recognition of their role in productivity.^[72]

Scientific and Cultural Uses

Lumbricus species, particularly L. terrestris and L. rubellus, serve as key model organisms in various scientific fields due to their accessibility, ethical advantages, and physiological similarities to higher organisms. In ecotoxicology, Lumbricus rubellus has been employed to study the metabolic perturbations caused by environmental pollutants such as copper, revealing coordinated changes in gene expression and enzyme activities that inform soil contamination assessments.^[73] Similarly, these earthworms facilitate laboratory experiments on soil ecosystem dynamics, burrowing mechanics, and population genetics, with standardized protocols ensuring reproducible results across studies.^[74] In neurophysiology, L. terrestris enables demonstrations of action potential conduction velocity, providing an inexpensive, invertebrate alternative for educational settings.^[75] Beyond ecology, Lumbricus contributes to biomedical research as a model for regeneration and vascular studies. Extracts from Lumbricus promote nerve cell regeneration in damaged rat sciatic nerves, supporting investigations into neural repair mechanisms.^[76] The species' closed circulatory system, with hemoglobin akin to human blood, has been adapted for microinjection techniques to model vascular responses in vivo.^[77] Additionally, L. terrestris serves as an ethical training model for microsurgery, offering a cost-effective substitute for vertebrates in skill development.^[78] Culturally, earthworms known as dilong—typically native Chinese species such as Pheretima aspergillum, with modern extracts often derived from Lumbricus—have been used for over 2,000 years in Traditional Chinese Medicine (TCM) to treat conditions like spasms, seizures, hypertension, and stroke by promoting blood circulation and resolving stasis, as documented in texts such as the Shennong Bencao Jing.^[79] Modern analyses confirm their fibrinolytic enzyme lumbrokinase, sourced from Lumbricus rubellus, reduces blood viscosity and fibrinogen levels, validating historical applications for thrombosis.^[80] In Ayurveda and Japanese folk medicine, local earthworm preparations address headaches, inflammation, and wounds, with pastes or extracts applied topically, while Lumbricus extracts are explored in contemporary research for similar effects.^[81] Historically, Lumbricus terrestris featured prominently in scientific discourse through Charles Darwin's 1881 publication The Formation of Vegetable Mould, Through the Action of Worms, with Observations on Their Habits, which elevated earthworms' role in soil formation and garnered widespread cultural interest in natural history.^[82] In some indigenous practices, such as among the Maori of New Zealand, earthworms (including introduced Lumbricus species alongside native ones) are consumed as delicacies or used medicinally for vitality, underscoring their dual role as sustenance and remedy in pre-modern and modern societies.^[81]

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This paper presents a new design and prototype of a worm-inspired metameric robot with a movement pattern similar to that of earthworms.
[33]
How Do Earthworms Move? - Sciencing
Mar 24, 2022 · The worm uses the setae to help anchor part of its body in place, while the muscles move the body forward or backward from that location.
[34]
Biomechanical limits to soil penetration by earthworms
Jul 4, 2018 · Anecic earthworms are characterized by their deep vertical burrowing activity [31], which may facilitate deep drainage processes and promote ...
[35]
Basic Research Tools for Earthworm Ecology - Butt - 2010
Nov 23, 2009 · ... burrowing (endogeic) species. Adults of deeper burrowing (anecic) species may be missed unless the researcher is prepared to dig a hole to a ...2. Collection Techniques... · 3. Burrowing And Burrow... · 4. Life History Studies
[36]
Dew-worms in white nights: High-latitude light constrains earthworm ...
Dew-worms display a diurnal vertical activity pattern, where individuals are nearest to the soil surface close to midnight and in the deepest position at noon ( ...Missing: circadian | Show results with:circadian
[37]
Worms make risky choices too: the effect of starvation on foraging in ...
Lumbricus terrestris are negatively phototactic annelids that feed on decaying plant matter at the soil surface. Feeding in high-light conditions is a ...
[38]
[PDF] Earthworm Species Composition and Distribution in the Upper ...
Jul 19, 2005 · The most important aspect of earthworm ecology is their feeding activity. Earthworms gain nutrition from the soil or leaf litter they ingest, ...
[39]
Earthworms as candidates for remediation of potentially toxic ...
According to Curry and Schmidt (2007), the amount of soil ingested was 0.2–6.7 g dry soil per gram of earthworm per day for geophagous worms. More specifically, ...Missing: daily | Show results with:daily
[40]
Digestive System of Earthworms - Microbe Notes
Dec 26, 2016 · The digestive system of earthworms consists of the alimentary canal and the digestive glands. Digestive System of Earthworm
[41]
The Function of the Calciferous Glands of Earthworms
The position of the calciferous glands in the oesophagus suggests that the secretion may be of importance in intestinal digestion, and if the organs are solely ...Missing: esophagus | Show results with:esophagus
[42]
Gut load and food-retention time in the earthworms Lumbricus ...
The gut contents of dung were lighter than the total ingested material, at about 0.10 and 0.07 g dry weight g-1 ash-free dry weight of worm, respectively.Missing: digestion efficiency
[43]
Enhancing earthworm (Lumbricus terrestris) tolerance to plastic ...
Feb 5, 2024 · While the microbiota associated with lignin degradation exhibited more variable results. In Fig. 1d, is observed how earthworms naturally ...
[44]
The Effects of Earthworms on Fungal Diversity and Community ...
Dec 16, 2020 · Earthworms can thus significantly increase the rate of decomposition of low-quality straw (high C/N, high lignin and polyphenol content) ( ...
[45]
[PDF] digestion process in lubmricus terrestris alters microbial enzyme ...
Earthworms consume the C-rich, nutrient-poor food substrate and breakdown the organic matter with the aid of microbial processes and the secretion of intestinal ...
[46]
Earthworm | University of Puget Sound
Earthworms have many predators. Moles seek them out underground, and a foraging robin should strike terror into the heart of all the worms that contemplate ...
[47]
Earthworm | NC State Extension - TurfFiles
Earthworms have some natural enemies including: ants, centipedes, birds, snakes, carabid beetles and nematodes. Chemical Control. There are no chemical ...Missing: predators | Show results with:predators
[48]
Earthworms - Missouri Department of Conservation
The appearance of invasive nonnative jumping worms (Amynthas and Metaphire spp.) in northern forests that were already damaged by nonnative Lumbricus earthworms ...
[49]
Earthworms as a prey source for the insular snake - Herpetozoa
Jul 10, 2024 · Its two native natricine snakes are known to feed on earthworms on the mainland; here, we confirm that eastern gartersnakes (Thamnophis sirtalis) ...
[50]
Injury-Induced Innate Immune Response During Segment ...
During evolution, the regeneration ability of earthworms has evolved probably due to predatory pressure and is achieved by the combination of epimorphic ...
[51]
Earthworms Building Up Soil Microbiota, a Review - Frontiers
The mutualistic interaction existing between earthworms and the soil microbiota has been named the “Sleeping Beauty Paradox” (Lavelle et al., 1995; Brown et al ...
[52]
Gut wall bacteria of earthworms: a natural selection process
Nov 19, 2009 · Earthworms and microorganisms are interdependent and their interactions regulate the biogeochemistry of terrestrial soils.
[53]
Earthworms Effect on Microbial Population and Soil Fertility as Well ...
Earthworms speed up the decomposition of organic matter by comminuting it to increase its usable surface area.
[54]
On the Nematodes of the Common Earthworm
It has long been a matter of common knowledge that larval nematodes inhabit the common earthworm, Lumbricus terrestris, Linn. They are found both in the cœlom ...
[55]
An opportunistic nematode parasite of earthworm cocoons
During a study on the breeding rate of the earthworms Lumbricus rubellus and Eisenia foetida, nematodes identified as Rhabditis terricola were found ...
[56]
Competitive interactions affect the growth of Aporrectodea ...
The objective of this study was to determine how inter- and intra-specific competition between Aporrectodea caliginosa and Lumbricus terrestris are affected by ...
[57]
Growth of Lumbricus terrestris and Aporrectodea caliginosa in an ...
Interspecific competition presumably prevails in earthworm population, but coexistence may well be possible for species with different feeding habits (Curry, ...
[58]
https://jdguez.webs.uvigo.es/wp-content/uploads/2013/05/Sexual-selection-in-earthworms.pdf
[59]
The mating behaviour of the earthworm Lumbricus terrestris ...
May 14, 2009 · We present a scheme for the mating of L. terrestris, discuss its different phases and propose a few lines for further studies. REFERENCES.
[60]
Precopulatory mate assessment in relation to body size in the ...
Our study provides the first quantitative data on mating behavior in Lumbricus terrestris. Mating frequency is relatively high (once every 7-11 days). This ...
[61]
On the Reproductive Processes of the Earthworm, Lumbricus terrestris
During the sexual congress of L. terrestris, the co-operating worms become attached to one another in a head-to-tail position.SEXUAL CONGRESS · The Structure of the clitellum · SOME NOTES ON THE...
[62]
Life cycle of an earthworm
Cocoons of Lumbricus terrestris. ... The two earthworms produce a slime tube and grip onto each other using the tubercula pubertatis (located on the saddle).
[63]
Aspects of the Biology of the Lumbricids Eiseniella tetraedra ... - jstor
At 15 and 200 C the incubation periods of both species were similar (about 40 and. 30 days respectively). At 70 C only one cocoon out of six deposited by ...
[64]
(PDF) Growth of hatchling earthworms in the presence of adults
Aug 6, 2025 · Hatchling Lumbricus terrestris, Aporrectodea longa, Allolobophora chlorotica and L. rubellus were cultured in 1-l pots at 15C in darkness.
[65]
Weight gain and weight loss of the earthworm Lumbricus terrestris L ...
The age at which incipent male pores appeared ranged from 9.4 weeks (20°C) to 25.7 weeks (7.5°C). The mean weight with incipient male pores and clitellum was ...
[66]
Earthworms - JardiBiodiv - Ephytia - INRAE
The cocoons will then hatch and give young worms which will reach sexual maturity in a few months (on average 3 months). Some earthworms like Lumbricus ...
[67]
Climate change effects on earthworms - a review - PMC
Earthworm activity, abundance, and biomass tend to increase with increasing temperature at sufficiently high soil water content.
[68]
Earthworms
### Summary of Agricultural Impact of Earthworms, Especially Lumbricus terrestris
[69]
How earthworms can help your soil
Earthworms offer many benefits: increased nutrient availability, better drainage, and a more stable soil structure, all of which help improve farm productivity.Missing: Lumbricus | Show results with:Lumbricus
[70]
Role of Earthworms in Soil Fertility Maintenance through the ...
Dec 14, 2009 · Their activity is beneficial because it can enhance soil nutrient cycling through the rapid incorporation of detritus into mineral soils. In ...
[71]
BE BOLD. Shape ... - Vermicomposting | New Mexico State University
The most common types of earthworms used for vermicomposting are brandling worms (Eisenia fetida) and redworms or red wigglers (Lumbricus rubellus). Often ...
[72]
Earthworms, the agriculturist's friends - Ecological Agriculture Projects
Oct 8, 1978 · Long before the invention of agricultural implements, earthworms ploughed the soil, mixing, tilling and building topsoil as they burrowed ...
[73]
'Systems toxicology' approach identifies coordinated metabolic ...
Jun 3, 2008 · We exposed earthworms (Lumbricus rubellus Hoffmeister) to sub-lethal levels of copper (10–480 mg/kg soil) for 70 days as a real-world situation ...
[74]
Using earthworms as model organisms in the laboratory
Mar 10, 2010 · The present paper provides recommendations for the planning and execution of earthworm experiments that help in achieving comparable results.
[75]
Portable conduction velocity experiments using earthworms for ... - NIH
The earthworm is ideal for studying action potential conduction velocity in a classroom setting, as its simple linear anatomy allows easy axon length ...
[76]
Dilong: Food for Thought and Medicine - PMC - PubMed Central
(2009) used Lumbricus, a widely known earthworm in Traditional Chinese Medicine, extract to show increased nerve cell regeneration in damaged nerves in rats.
[77]
A Novel Microinjection Vasculature In vivo Invertebrate Model
Apr 1, 2021 · The earthworm model provides a simple closed vascular circulatory system with a hemoglobin structure similar to human blood. A protocol is ...
[78]
Lumbricus terrestris, a reliable animal model for training?
The earthworm appears to be a reliable experimental model for microsurgical training. It is more ethical than using rats, less expensive than vertebrate animal ...Missing: scientific | Show results with:scientific
[79]
Earthworms Dilong: Ancient, Inexpensive, Noncontroversial Models ...
In TCM, using Lumbricus is one method employed for millennia in China to promote nerve function.
[80]
Effect of Earthworm on Wound Healing: A Systematic Review and ...
In China, earthworms (Lumbricus spp.), also called dilong, are used to treat various ailments, including burns, arthritis, itching, and inflammation.
[81]
[PDF] Earthworms: A Source of Protein - David Publishing
Abstract: Earthworms are important invertebrates that have been widely used as food and traditional medicine sources for thousands of years.
[82]
Charles Darwin′s Observations on the Behaviour of Earthworms ...
Mar 7, 2010 · Here we describe the origin, content, and impact of Darwin′s last publication on earthworms (subclass Oligochaeta, family Lumbricidae) and the ...Missing: cultural | Show results with:cultural