An Earthworm Animal Information In English. Earthworm is an animal familiar to everyone. Which we can see everywhere in rainy days. Earthworms belong to the class Oligochaeta of the order Annelida. There are 150 species of earthworms and their 3000 species. Earthworms are found everywhere in India. The scientific name of the earthworm found in India is Pherotima posthuma. These animals are widely used for dissection in zoological laboratories.

Worm farming is also practiced by many people. Vermicompost is produced from it. Some species of earthworms have a process. Also known as worm farming. Vermicompost is similar to the product of manure processing; But there is a slight difference in this, due to application of this fertilizer in the field, the productivity of the farm increases.

 An Earthworm animal Information In English

An Earthworms are harmless, often beneficial residents of the soil. Earthworms breakdown dead and decaying organic matter into rich humus soil, thereby supporting plant growth. They also dig tiny channels and make holes that aerate soil and improve drainage.


An Earthworms don’t have lungs; they breathe through their skin. They also lack eyes, so instead use receptors in their skin to sense light and touch. Earthworms have five “hearts” that pump blood through their bodies.

An Earthworm animal Information In English

It uses red winglers, white worms and earthworms to produce a heterogeneous mixture of worm casts, straw material and food waste. Worm feed contains water-soluble nutrients in which the nutrients form an organic fertilizer.

• Domain - Eukaryota
• State - animal
• Phylum - Annelida
• Class - Clitellata
• Order - Opistopora
• Subdivision - Lumbricina

They act as the best soil conditioners, so they are widely used in small scale organic farming. Also used for oxygen demand from black water or sewage. Cultivation of earthworms can be done in the basement or even in the balcony. The advantage of a worm bin is that we can speed up this process. So let's see the detailed information about this animal earthworm.

What are An Earthworms?


The term Earthworm refers to a specific group of invertebrates within the taxonomic phylum Annelida. Earthworms belong to the Oligochaetes-which means 'few bristles' and are represented by 31 species of earthworm here in the British Isles. Worldwide there are over 5,000 species described and advances in taxonomy using DNA is changing this, highlighting new species and new subspecies.

Earthworms are, as their name suggests, terrestrial, their skin is permeable and they need a moist environment so they don't dry out. The different species of earthworms have individual requirements just as a dog has from a cat, some earthworm species live in compost, some live in permanent burrows deep down in the soil, others are content with the middle ground and make complex networks of tunnels as they explore the earth. There is still a lot we don't know about them, and the Earthworm Society of Britain aims to improve this!

Where does earthworm live?

Earthworm is an animal found in the soil and is also called a farmer's friend. That is, the earthworm is likened to a farmer's friend. Earthworms are found in animal shelters, wetlands, and soils rich in organic matter. Also, they live by burrowing in the soil and rotting the ground.

 An Earthworm animal Information In English

Earthworms are commonly found in moist, compost-rich soil, eating a wide variety of organic matters, which include detritus, living protozoa, rotifers, nematodes, bacteria, fungi and other microorganisms.

What do An earthworms eat?

There are earthworms everywhere. China, Greenland, Australia, and the Sahara Desert are just a few nations with unique native species. Some species can be found in decaying logs, the axils of tree branches (the upper angle between the branch and the trunk, sometimes up to 10 m above ground), or along the moist soil surrounding bodies of water (lakes, rivers, springs, ponds), even though some species live in the surface layer or in different horizons (layers) of the soil.Even with this vast range of habitats, an earthworm's survival still depends on a few environmental factors:

• A sufficient amount of food must always be nearby for all earthworms. Earthworms typically stay around their feeding source.
• Since earthworms don't have lungs, they breathe through their skin and require moisture to do so, hence they all require a damp atmosphere. The dissolved oxygen is trapped by the internal fluids that earthworms release, such as sweat.
  
  

Earthworms eat a range of matter. In Earthworms, by Sims and Gerard (1985), most earthworms are described as omnivorous (eating plants and animals). However they better described as detritivores (eating decaying plant and animal matter).

Since then the study of earthworms has shown that they may be preferential fungivores (eating fungi). There are studies to suggest they eat a fungus called mycorrhiza which grows on the roots of some plants. Some species have also been described as geophagous (soil eating).


In the UK there are four different ecotypes, they show the diversity of different feeding niches:

• Composting earthworms feed on decaying plant matter and manure that is near the start of the decomposition process.
• Epigeic earthworms live in leaf litter and rotting logs and feed on organic matter that is partially decayed.
• Anecic earthworms pull decaying plant matter in to their burrows.
• Endogeics earthworms eat soil which is high in organic matter.

Commonly found in soils, earthworms are segmented, tube-shaped worms. For little and medium-sized creatures like fish, birds, and raccoons, they are among the most significant species in the food chain. As they feed on smaller creatures, they also aid in the aeration and decomposition of soil. 

 An Earthworm animal Information In English

Earthworms typically possess both male and female sex organs, making them hermaphrodites. They don't have an internal skeleton, but they nonetheless have a fluid-filled coelom chamber that serves as a hydrostatic skeleton. Earthworms have a basic digestive system that extends the length of their bodies.

Habit and Habitat of Earthworm in English

• The Earthworms are burrowers. It prefers to live in the burrow during the day and comes out at night and in damp cloudy weather for the search of food, reproduction, and exploring fresh habit. Thus, nocturnal in habit.
• The rainy season is the most favorable time for earthworms, after heavy rainfall, it leaves burrow and are seen in large numbers crawling on the ground.
• They breed during the rainy season.
• They are found in soil rich decaying organic matters usually in the garden, pastures, lawns, irrigated farmlands, near the banks of ponds, lakes, and rivers.
• They are cold-blooded or poikilothermal as their body temperature fluctuates with the surrounding temperature.
• They feed on dead organic matters, food and soil are ingested together and the latter, along with undigested food is finally egested in the form of worm casting.
• They are hermaphrodites, but they undergo copulation for exchange of their spermatozoa.
• Fertilization and development occur inside the cocoon.
• The natural life span of earthworm varies from 3 and a half years to 10 years.

Life cycle of an earthworm in English

The earthworm life cycle, like many others, starts with an egg. Within the egg, a young earthworm develops until it is ready to hatch. The egg is encased in an egg casing called a cocoon. The number of eggs within one cocoon can vary between species, ranging between 1 and 20 from earthworm species in the family Lumbricidae (but most species have just 1).

 An Earthworm animal Information In English

• Cocoons tend to be ‘lemon’ shaped, but the specific shape varies between species. The amount of time that they take to hatch is also very variable and can vary by species, but also by environmental conditions. For example, for some species the cocoons may hatch quicker in warmer conditions than in cooler conditions and other species may ‘wait out’ undesirable drought conditions within the soil as the cocoon stage.
• Hatchlings look just like mini-earthworms, they’re just smaller and paler. It can be easy to confuse these with potworms (Enchytraeidae), which are small segmented worms that are closely related to earthworms. As the hatchling feeds and grows it will gain the same colour as an adult earthworm.
• Juvenile earthworms look very much like the adults but are missing the saddle (or clitellum).
• Adults (or sexually mature) earthworms can be easily recognised through the presence of the saddle. Earthworms are hermaphrodite organisms, meaning that each earthworm has both male and female sexual reproduction organs.
• Sexual reproduction involves two earthworms. The two earthworms produce a slime tube and grip onto each other using the tubercula pubertatis (located on the saddle). The slime tube provides the right environment for the two earthworms to exchange sperm, with each earthworm storing the sperm of it’s partner for use later. Because both earthworms are performing the function of both a male and female during sexual reproduction, they are known as simultaneous hermaphrodites. Following this sperm exchange the earthworms separate.
• “Asexual reproduction can also be undertaken by some species of earthworm. This involves a single earthworm producing young from unfertilised eggs and is known as parthenogenesis.”
• A mucus sheath is formed around the clitellum and is moved along the earthworm until it comes off the head end. Along this journey it picks up the egg(s) and the sperm of the earthworm that was mated with. This mucus sheath forms the cocoon and fertilisation of the egg occurs within the cocoon.

Earthworm Anatomy in English

1. Segmented Body

Earthworms are classified in the phylum Annelida or Annelids. Annelida in Latin means, “little rings.” The body of the earthworm is segmented which looks like many little rings joined or fused together. The earthworm is made of about 100-150 segments. The segmented body parts provide important structural functions. Segmentation can help the earthworm move. Each segment or section has muscles and bristles called setae. 

 An Earthworm animal Information In English

The bristles or setae help anchor and control the worm when moving through soil. The bristles hold a section of the worm firmly into the ground while the other part of the body protrudes forward. The earthworm uses segments to either contract or relax independently to cause the body to lengthen in one area or contract in other areas. Segmentation helps the worm to be flexible and strong in its movement. If each segment moved together without being independent, the earthworm would be stationary.

2. Digestive System

The digestive system is partitioned into many regions, each with a certain function. The digestive system consists of the pharynx, the esophagus, the crop, the intestine and the gizzard. Food such as soil enters the earthworm’s mouth where it is swallowed by the pharynx. Then the soil passes through the esophagus, which has calciferous glands that release calcium carbonate to rid the earthworm’s body of excess calcium. 

After it passes through the esophagus, the food moves into the crop where it is stored and then eventually moves into the gizzard. The gizzard uses stones that the earthworm eats to grind the food completely. The food moves into the intestines as gland cells in the intestine release fluids to aid in the digestive process. The intestinal wall contains blood vessels where the digested food is absorbed and transported to the rest of the body.

3. Circulatory System

Another important organ system is the circulatory system. The earthworm has a closed circulatory system. An earthworm circulates blood exclusively through vessels. There are three main vessels that supply the blood to organs within the earthworm. These vessels are the aortic arches, dorsal blood vessels, and ventral blood vessels. The aortic arches function like a human heart. 

There are five pairs of aortic arches, which have the responsibility of pumping blood into the dorsal and ventral blood vessels. The dorsal blood vessels are responsible for carrying blood to the front of the earthworm’s body. The ventral blood vessels are responsible for carrying blood to the back of the earthworm’s body.

4. Respiratory System

Earthworms do not have lungs. They breathe through their skin. Oxygen and carbon dioxide pass through the earthworm’s skin by diffusion. For diffusion to occur, the earthworm’s skin must be kept moist. Body fluid and mucous is released to keep its skin moist. Earthworms therefore, need to be in damp or moist soil. This is one reason why they usually surface at night when it is possibly cooler and the “evaporating potential of the air is low.” 

Earthworms have developed the ability to detect light even though they cannot see. They have tissue located at the earthworm’s head that is sensitive to light. These tissues enable an earthworm to detect light and not surface during the daytime where they could be affected by the sun.

Earthworm Reproduction in English

The world would be very different without our Australian tiny friends. The livelihood of earthworms is crucial to the condition of our soil. Long-term sustainability of the environment and, consequently, our own survival will depend on having healthy, high-quality soils. Plant development, the control and distribution of surface to ground water, and the buffering, detoxification, and scrubbing of dangerous substances all depend on the biological, chemical, and physical characteristics of soil. In reality, biological diversity in the soil is probably greater than that of aboveground ecosystems.

There are some special roles that earthworms play in the soil. Their expansive burrows facilitate the easy infiltration of rainwater into the soil, hence accelerating soil infiltration. This allows water to access the roots zone, where plants may use it, and stops water erosion. Additionally, their tunnels facilitate the easy passage of roots into new areas via the soil. It is less likely for earthworm-worked soil to blow away in the wind because of its solid crumb-like texture.

Earthworms are thought to play a significant role in the cycling of organic materials in soil. While certain species actively participate in the decomposition process, releasing vital nutrients for other living things in the soil, such as plants, other species are in charge of burying surface debris.

Earthworms are hermaphrodites where each earthworm contains both male and female sex organs. The male and female sex organs can produce sperm and egg respectively in each earthworm. Although earthworms are hermaphrodites, most need a mate to reproduce. During mating, two worms line up inverted from each other so sperm can be exchanged. The earthworms each have two male openings and two sperm receptacles, which take in the sperm from another mate. 

The earthworms have a pair of ovaries that produce eggs. The clitellum will form a slime tube around it, which will fill with an albuminous fluid. The earthworm will move forward out of the slime tube. As the earthworm passes through the slime tube, the tube will pass over the female pore picking up eggs. The tube will continue to move down the earthworm and pass over the male pore called the spermatheca which has the stored sperm called the spermatozoa. 

 An Earthworm animal Information In English

The eggs will fertilize and the slime tube will close off as the worm moves completely out of the tube. The slime tube will form an “egg cocoon” and be put into the soil. The fertilized eggs will develop and become young worms.

Reproductive System of Earthworm in English

Male and Female Reproductive System of Earthworm

The common earthworm, Lumbricus terrestris, is a cylindrical, segmented and tubular worm which plays an important part in maintaining the ecosystem. The reproductive system of earthworms is not very complicated given that all species are hermaphrodites.That is, they each have a set of female and male organs.

It would help if you remembered that earthworm reproduction is not always parthenogenetic, which is a form of asexual reproduction. As advanced students of biology, you must study further on sexual and sexual types of reproduction.Let us proceed and find out more about how earthworms reproduce.



How do Earthworms Reproduce?

To answer that, we need first to identify the reproductive organs of an earthworm. Let us first analyse the male reproductive system.



Male Reproductive System

The most important organs are listed below.

Testes & Testes Sac: Two pairs of testes are located at the 10th and 11th segments. These produce spermatogonia. The sac is white, with wide walls and is filled with fluid. The sac is bi-lobed, and the first sac at the 10th segment is larger than the second once since it houses the earthworm’s seminal vesicles as well.


Seminal Vesicles: An earthworm has two pairs of seminal vesicles. Experts state that seminal vesicles of earthworms evolved nearly 1 million years ago and precedes parthenogenesis. The spermatogonia mature in these vesicles and develop into spermatozoa. These are mature sperms; producing them is the main function of testes in earthworms.


Seminal Funnel: Earthworms have two pairs of seminal funnels. These are located at the 10th and 11th segments. These ciliated funnels play an essential role in passing on spermatozoa to the Vasa deferentia and onwards.



Female Reproductive System in English

The most important organs of the female reproductive system of earthworm are the following -

• Ovaries: There is a single pair of ovaries attached to the 12th and 13th septa. Ova and multiple ovarian lobules rest within an earthworm ovary. Once the ova matures, it gradually moves towards the coelomic cavity. Before maturation, they rest in an ovary’s dorsal end.

• Oviducal Funnel: A saucer-shaped structure, an oviducal funnel is located in the 13th segment. The funnel plays an important role in collecting matured ova after an ovary of earthworm produces them. The funnel ends in a short and conical tube-like structure called an oviduct. Two of these oviducts meet at the 14th segment and then open out into the external genital pore.

• Spermatheca: Each earthworm has 4 pairs of spermatheca. They are flask-shaped and have a short diverticulum. This is the area where sperm is stored. The 4 pairs are located laterally at the 5th to 9th segments.

• A task for you: Identify the various segments of these worms in your school’s laboratory. Try to locate the 12th and 13th septa. Some earthworms have naturally well-developed clitellums. That is why there is a ‘bulge’ on an earthworm. Clitellums are also found in leeches.

Earthworms Help The Environment in English

Earthworms are more than just fish bait. They are the main contributors to enriching and improving soil for plants, animals and even humans. Earthworms create tunnels in the soil by burrowing, which aerates the soil to allow air, water and nutrients to reach deep within the soil. Earthworms eat the soil which has organic matter such as decaying vegetation or leaves. Plants cannot use this organic matter directly. After organic matter is digested, the earthworm releases waste from their bodies called castings. Castings contain many nutrients that the plant can use. Some people even use earthworm castings as garden fertilizer.

Earthworm: brief about the creature in English

Biologically classified under the animal kingdom and the phylum of annelida, the scientific name for an earthworm is Lumbricus terrestris. They occur all over the world and are generally found in muddy soils or humid climates.

An earthworm is an invertebrate, meaning it does not have a vertebra. This means it lacks a skeleton but the body structure is maintained by a skeleton that is supported by fluid pressure or a hydrostatic skeleton. Its body is long and tube-like and bears segments; both on the inside and outside. They thrive on organic matter, hence being its primary food.

The digestive system of an earthworm lies throughout the length of its body and the respiratory organ for an earthworm is its skin. Earthworms are hermaphrodites which means that the male and female reproductive organs lie in the same body. When they mate, two earthworms exchange sperm and fertilise the eggs of the other.
Ecological importance

Earthworms are often called the farmer’s friends. There is a reason for this. Earthworms help in breaking down organic particles like dead leaves, animals to organic manure and this in turn replenishes the soil with rich nutrients which increases overall soil fertility.

The earthworm also breaks down small particles like sand and soil, which again help in increasing the fertility of soil. The earthworm leaves behind casts of its body which are very rich in nitrogen and phosphates. This balances out the lost nutrients in the soil.

The burrowing motion of the earthworm creates channels in the soil which allows air and water to pass through to the deepest layers of soil. Not only does it improve aeration in the soil, it also brings an improvement in the drainage of soil. This burrowing motion also again adds nutrients to the soil in the form of body casts that are left deeper in hence increasing nutrient uptake in the plant.

Due to these reasons earthworms are used widely in vermicomposting and when projects related to soil restoration are taken. They prepare the soil to grow natural plants especially when there has been an attack of an invasive species.

They are also used as fish bait and help humans increase fishing yield.

• The function of the body wall of Earthworm
• It provides definite shape to the body (due to its elasticity).
• The mucus secreted by the mucous gland of the epidermis keeps the body smooth and moist helps in respiration and locomotion.
• Protects the internal delicate organ from injury.
• Secrete mucus which keeps the body surface slimy and kills harmful bacteria.
• Alternative contraction and relaxation of circular and inner longitudinal muscle help in movement.
• Albumen secreted by the clitellar gland helps in the nutrition of embryo developing inside the cocoon.
• Sensory epidermal cells are the only receptors to receive external stimuli.
• The coelomic epithelium or peritoneal layer secrets the coelomic fluid.
• The cuticle checks excess evaporation.

Reproductive System of Earthworm in English

Male and Female Reproductive System of Earthworm

The common earthworm, Lumbricus terrestris, is a cylindrical, segmented and tubular worm which plays an important part in maintaining the ecosystem. The reproductive system of earthworms is not very complicated given that all species are hermaphrodites.That is, they each have a set of female and male organs.

It would help if you remembered that earthworm reproduction is not always parthenogenetic, which is a form of asexual reproduction. As advanced students of biology, you must study further on sexual and sexual types of reproduction.Let us proceed and find out more about how earthworms reproduce.



How do Earthworms Reproduce?

To answer that, we need first to identify the reproductive organs of an earthworm. Let us first analyse the male reproductive system.



Male Reproductive System

The most important organs are listed below.

Testes & Testes Sac: Two pairs of testes are located at the 10th and 11th segments. These produce spermatogonia. The sac is white, with wide walls and is filled with fluid. The sac is bi-lobed, and the first sac at the 10th segment is larger than the second once since it houses the earthworm’s seminal vesicles as well.


Seminal Vesicles: An earthworm has two pairs of seminal vesicles. Experts state that seminal vesicles of earthworms evolved nearly 1 million years ago and precedes parthenogenesis. The spermatogonia mature in these vesicles and develop into spermatozoa. These are mature sperms; producing them is the main function of testes in earthworms.


Seminal Funnel: Earthworms have two pairs of seminal funnels. These are located at the 10th and 11th segments. These ciliated funnels play an essential role in passing on spermatozoa to the Vasa deferentia and onwards.



Female Reproductive System in English

The most important organs of the female reproductive system of earthworm are the following -

• Ovaries: There is a single pair of ovaries attached to the 12th and 13th septa. Ova and multiple ovarian lobules rest within an earthworm ovary. Once the ova matures, it gradually moves towards the coelomic cavity. Before maturation, they rest in an ovary’s dorsal end.

• Oviducal Funnel: A saucer-shaped structure, an oviducal funnel is located in the 13th segment. The funnel plays an important role in collecting matured ova after an ovary of earthworm produces them. The funnel ends in a short and conical tube-like structure called an oviduct. Two of these oviducts meet at the 14th segment and then open out into the external genital pore.

• Spermatheca: Each earthworm has 4 pairs of spermatheca. They are flask-shaped and have a short diverticulum. This is the area where sperm is stored. The 4 pairs are located laterally at the 5th to 9th segments.

• A task for you: Identify the various segments of these worms in your school’s laboratory. Try to locate the 12th and 13th septa. Some earthworms have naturally well-developed clitellums. That is why there is a ‘bulge’ on an earthworm. Clitellums are also found in leeches.

Earthworm Copulation in English

Now that you have an idea of the physical parts of the reproductive system of earthworms, we come to copulation. Earthworms are nocturnal creatures. Copulation generally occurs during night-time in the months of July to October, i.e. monsoon.

Earthworms are simultaneous hermaphrodites, and hence reproduction involves both copulation and cross-fertilisation.Copulation is completed once spermatozoa from one worm is transferred to another. During mating seasons, two worms will attach ventrally to each other, allowing prostatic fluid and sperm exchange via an earthworm’s spermathecal pore.

These are then stored within the respective spermatheca.This process of copulation lasts for about an hour. The worms will then separate and eggs in cocoons will be laid after a few days. Earthworms have no larval stage; a young worm emerges from these cocoons, fully formed. These young individuals have no clitellum.

Known for their iteroparous nature, earthworms also never stop growing. Some species have been known to grow to as much as 14 inches long. These invertebrates can dig down up to 6.5 feet.

 
Types of Earthworms in English

There are three categories that earthworms fall into, and these can be defined by that part of the environment the worm predominantly inhabits. These three main types of earthworms are epigeic worms, which are also known as surface dwellers because they live above soil level, endogeic worms, which live below ground, and anecic worms, which live below soil level but explore at and above soil level to find sources of food.

It’s important to note and understand the differences that these types of worms have in order to recognize their differing roles within our ecosystem. For example, a worm that is good for composting will likely be an epigeic worm, as these worms feed voraciously and quickly excrete nutrients to help with the decomposition of compost. A well-intentioned gardener might move worms found in compost to their garden soil in an effort to improve soil quality, but as these worms do not burrow and will not happily live below soil level, they will be useless if placed


1. Epigeic earthworms :


‘Epigeic’ is the Greek translation for ‘on the earth,’ because these worms do not build burrows, and instead reside amongst decaying organic matter on the soil surface. These are also sometimes called compost earthworms, or surface-dwelling earthworms, as they live on the surface of the soil amongst piles of leaves or compost heaps. They feed on decaying plant matter, leaf litter, and dung. They are weak burrowers, and therefore prefer to live amongst loose organic materials and topsoil.


They have a dark coloring that enables them to live above ground more safely, camouflaging themselves in piles of leaves or topsoil. Their dark pigmentation also helps to protect them from UV rays. They have strong muscles for their size, which enables them to move faster than other types of worms, which is important as living above ground they are most at risk from predators. 

These worms are important in composting and are known to rapidly consume and excrete composting material to help it break down more quickly. They are also able to reproduce very quickly, increasing the population of worms within the compost. They are small in size, usually ranging from between less than an inch up to seven inches in length.


2. Endogeic earthworms


‘Endogeic’ translates from Greek to mean ‘within the earth,’ and accordingly, these worms burrow within the top layers of soil and rarely come up to the surface, preferring instead to literally live within the earth. They are most commonly found in the uppermost layers of soil where they create semi-permanent, horizontal burrows or under rocks and logs, though some will burrow deep into the soil. They typically only make an appearance on the ground surface in instances of heavy rain, as the extra moisture prevents them from drying out.


These worms are fairly small and generally measure between one and twelve inches. They tend to be very pale or translucent and colorless, and they have weaker muscles than epigeic worms,
which means they move more slowly. They help to mix minerals and air within the soil and help with aeration as they eat the soil itself.

3. Anecic earthworms

‘Anecic’ is greek for ‘out of the earth,’ because although these worms live below ground, they come up to soil level for their food. These worms are those that burrow vertically in the mineral layers of soil, creating permanent burrows as deep as six feet below surface level. Their burrow systems are quite extensive and can be as big as one inch in diameter. These worms collect food from above ground in the form of organic matter such as fallen leaves and drag them back underground to their burrows. They are also known to eat soil and some litter.


These worms encompass some of the most common types of earthworms, worms used for fishing bait, and nightcrawlers. They have very weak muscles and are the slowest moving of all types of worms, as they do not have any need to move quickly. They have some pigmentation but are often a milky color, especially native worms, as they predominantly reside underground. They can drastically range in size, anywhere from one inch to a huge sixty inches in length (University of Alberta).


Benefits to soil fertility in English

The major benefits of earthworm activities to soil fertility can be summarized as:

 
1) Biological :- The earthworm is essential to composting; the process of converting dead organic matter into rich humus, a medium vital to the growth of healthy plants, and thus ensuring the continuance of the cycle of fertility. This is achieved by the worm's actions of pulling down below any organic matter deposited on the soil surface, either for food or when it needs to plug its burrow. 

Earthworms often come to the surface and graze on the higher concentrations of organic matter present there, such as leaves or manure. Once in the burrow, the worm will shred the leaf and partially digest it, then mingle it with the earth by saturating it with intestinal secretions.

2) Chemical :- As well as dead organic matter, the earthworm also ingests any other soil particles that are small enough (including stones up to 1/20 of an inch across) into its "crop." In the crop, minute fragments of grit grind everything into a fine paste, which is then digested in the stomach. When the worm excretes this in the form of worm casts, which are deposited on the surface or deeper in the soil, a perfectly balanced selection of minerals and plant nutrients is made available in an accessible form. 

Investigations in the US show that fresh earthworm casts are five times richer in available nitrogen, seven times richer in available phosphates, and 11 times richer in available potash than the surrounding upper 6 inches (150 mm) of soil. In conditions where there is plenty of available humus, the weight of casts produced may be greater than 4.5 kg (10 lb) per worm per year, in itself an indicator of why it pays the gardener or farmer to keep worm populations high.

3) Physical :- The process of the earthworm moving through compacted soil—sometimes ingesting the soil, grinding it up, and depositing the waste—aerates and mixes the soil, and is constructive to nutrient uptake by vegetation. By its burrowing actions, the earthworm is of great value in keeping the soil structure open, creating a multitude of channels which allow the processes of both aeration and drainage to occur. 

Permaculture co-founder Bill Mollison points out that by sliding in their tunnels, earthworms "act as an innumerable army of pistons pumping air in and out of the soils on a 24 hour cycle (more rapidly at night)" (Mollison 1988). Thus, the earthworm not only creates passages for air and water to traverse, but is itself a vital component in the living biosystem that is healthy soil.

Benefits of Earthworms in English 

 

The burrowing and feeding activity of earthworms have numerous beneficial effects on overall soil quality for crop production. The following soil properties can be improved by earthworms.

Water infiltration

Some earthworm species create vertical burrows, whereas other species live in horizontal burrows in the soil. The vertical burrows are typically open, although the worms cap the top with residue and excrement. The vertical burrows are very important points of entry for quick water infiltration into the soil, especially in no-till systems.

Soil aeration

Air-filled porosity is critical in helping plant roots to thrive. Roots need oxygen for their growth, whereas they produce carbon dioxide that needs to leave the soil. Because earthworms improve soil porosity, they improve the exchange of these gases with the atmosphere. Earthworms increase porosity by two mechanisms: (1) by creating permanent burrows, and (2) by improving soil aggregation. Aggregation is improved by the mixing of soil and organic matter in the earthworms' guts. 

These highly stable aggregates are deposited by some earthworms in their burrows, and by others at the surface of the soil. In one pasture study, earthworms consumed between 20 and 40 tons of soil per acre per year. In another study, earthworms were estimated to consume 4 to 10 percent of the top 6 inches of the soil annually. This only goes to show the enormous amounts of soil that can be processed by earthworms.

Soil compaction and soil tilth

Soil compaction reduces the porosity of the soil. Because earthworms increase porosity, they reduce the effects of compaction. In addition, the excrement of earthworms has a very stable structure, which makes the soil more resistant to compaction and improves its tilth.

Soil organic matter

Typical earthworm populations can easily consume 2 tons of dry matter per acre per year, partly digesting and mixing it with soil. The importance of earthworms to mix surface residue with soil becomes very clear in soils that do not have any earthworms. Most of our Pennsylvania soils have at least some earthworms and the effect of

 

 their complete absence therefore cannot be noted. In the Netherlands, some soils reclaimed from the sea at first did not have any earthworms. In these soils the formation of topsoil with reasonable organic matter content did not take place, resulting in poor crop growth. Once the cause was established, the government of the Netherlands started a campaign to introduce earthworms. After the introduction of the earthworms, a dark topsoil layer was formed, and crop growth increased substantially.

Plant available nutrients

Earthworm casts have higher available nitrogen, phosphorus, potassium, and calcium contents than surrounding soil, as well as a higher cation-exchange capacity. Some micronutrients, such as zinc and boron, are more available in the excrement of earthworms through chelation of the micronutrients.

Soil pH

Soil passed through the gut of earthworms has a neutral pH. This is probably due to the pH buffering action of organic molecules produced in the gut of worms.

Beneficial microbes

Earthworms excrete material that has high concentrations of beneficial microbes that help decompose crop residue.

Nematode control

Some earthworms eat harmful nematodes, thus decreasing the concentration of these harmful organisms in soil.

Interesting Earthworm Facts in English

 
1. The largest worm was 21 feet long

In 1967, a colossal earthworm was found in South Africa that measured 21 ft (6.7m) long.

This impressive find has blown the UK record of 15.7 inches (40cm) out of the water, but the latter, named Dave, has been immortalised in the museum database, making it possibly the largest worm called Dave in the world.

 
2. Earthworm can breathe underwater

Earthworms breathe through their skin, which is quite common in slimy, soft-bodied creatures.

They’re also cold-blooded so have a very slow metabolism. These things combined allow earthworms to absorb enough oxygen from water to keep them alive for months when submerged.

 
3. There’s various theories to why earthworms come to the surface when it rains

Convential wisdom is that earthworms escape to the surface to stop drowning, however as shown in the previous fact, they can breathe underwater. Tests have actually shown they can survive being submerged in water for over two weeks.

Therefore the popular drowning explanation is a myth, and researchers have proposed various other theories. These include –

• Earthworms find it easier to travel across the surface when it’s wet (to find food, or a mate). They need to stay moist, so this is their best opportunity on the surface.
• Rain drops sound like predators (such as moles, that make vibrations in the soil as they hunt), and subsequently worms come to the surface to escape.
• Earthworm and soil experts are starting to settle on the first theory above around enabling them to travel on the surface as the most likely explanation.
• Interestingly, birds have recognised and exploit this behaviour by mimicking rain by hitting the ground with their feet to encourage earthworms to rise to the surface to eat them!

4. They are dominant almost everywhere

In most soils, anywhere in the world, earthworms are the dominant group of microfauna. In fact, in a single hectare, there can be two tons of worms! That’s over a million individuals.

Worms are so prevalent because there is a vast diversity of species and they’re so good at munching leaves that fall to the ground. Better than any other invertebrate, in fact.

 
5. Earthworms don’t have eyes

Although, some worms do. Eyes are not really needed when you spend your life in the dark soil.

However, they do have special photosensitive cells called “light cells of Hess”, that allow them to sense light at their front-end. They will move away from light and can become paralyzed if exposed to light for too long.

 
6. They make group decisions

In such high densities, they need to be able to get along, and it turns out they do.

Communicating by touch, earthworms can form large clusters that communicate as a sort of hive mind and work together sharing information and making decisions on what to do next.

7. They move underground by contracting muscles in their bodies

The contracting and relaxation of different muscles alternates shortening and lengthening their body that produces a wave like effect in their tube-in-a-tube body to move.To aid the burrowing process, they can also secrete mucus which allows them to glide through the soil. Adults are able to push 10 times their own body weight in mass.

8. Eathworms can regenerate lost segments

Regeneration depends on the species of eathworm and the amount of damage to the worm where it has been cut, but many worms are able to regenerate and replace a lost tail.

They cannot survive if the front part of their body between the head and saddle is cut (where much of their major organs are). It’s also a common misconception that if you cut them in half they can make two new worms, unfortunately they will likely just die (or potentially the head end may survive).

 
9. They’re mostly hermaphrodites

Most earthworms are hermaphrodites, meaning they have the sex organs of both male and female worms. This is a pretty incredible strategy for reproduction as it means that both mates can share genetic information and pass it on; essentially doubling the effectiveness of mating.

Some of these copulations last up to 200 minutes though, so it’s probably a good idea to get as much out of that as possible.

 
10. But sometimes they just clone themselves

However, up to 40% of worms don’t need to mate at all.This strange form of reproduction is called parthenogenesis and it’s not very well understood, but it means that even if nobody fancies them, certain earthworms can reproduce by themselves.

 
11. They use gizzard stones for digestion

Just like many birds and crocodiles, and that triceratops from Jurassic Park, earthworms swallow stones to help them digest food.Stones are often used in place of teeth, to grind up vegetation and help expose the nutrients inside for digestion. Interestingly, the name for gizzard stones is ‘gastrolith’, which is also a great name for a hard rock band.

 
12. They have 10 hearts!

Earthworm circulation is performed by way of paired aortic arches. These are paired valves that work similarly to a heart, pushing blood in one direction and pulling it back in the other.Earthworms have five pairs of these, and half carry blood forward to the front end of the worm, while the other half carry it to the rear.

This is a form of the closed circulatory system, just like ours.

The blood is contained inside vessels and pumped around the body in a circuit. In many invertebrates, this isn’t the case. Often there will be a simple pumping of fluids around an open system that just sort of washes the inside of the body with blood to extract and exchange nutrients and waste.

 
13. They eat litter!

When the leaves of a plant fall in the autumn, or we throw out our vegetable scraps into the compost, they gradually decompose. This is so common that we sort of take it for granted, but the process itself is an active one.

Numerous microorganisms and invertebrates take part in this process, and earthworms are some of the most critical. Without them, leaves and would just sit around on the ground. We call this leaf litter, and it’s one of the earthworm’s favourite foods.

 
14. Earthworms engineer the soil

Earthworm burrows mix soil horizons, aerate the substrate and convert complex organic matter into nutrient-rich poops that sit on the soil surface and are readily available to plants. This also helps protect from soil erosion and structural stability of the growing medium for plants.

This means that they’re critical to the growth of our food and our trees. Without earthworms, soil density would increase over time, too, reducing the ability of roots to breathe and take up water.










FAQ

What kind of animal is an earthworm?

Earthworm, also called angleworm, any of more than 1,800 species of terrestrial worms in the class Oligochaeta (phylum Annelida) – specifically, members of the genus Lumbricus. Seventeen native species and 13 introduced species (from Europe) occur in the eastern United States, L. Terrestris are the most common.


How long do earthworms live?

People with a healthy country lifestyle can live up to eight years, but city gardens typically live 1-2 years.


Where do earthworms live?

Lives in the top few centimeters of the soil


What family do earthworms belong to?

A segmented worm of the class Oligochaeta of the phylum Annelida. This class includes about 14 families, including the Lumbricidae, which includes the common earthworm (Lumbricus terrestris).