20 Earthworm Facts: The Wonders of These Wriggly Creatures

Earthworms are a fascinating group of creatures that play a vital role in properly maintaining the health of soils and ecosystems.

These are one kind of terrestrial invertebrate that falls under the phylum Annelida. These creatures live worldwide where temperature, water, and soil allow.

These creatures live in the soil and eat various organic matter, including plant matter, living bacteria, fungi, protozoa, nematodes, and many more.

So, in this article, we will talk about some amazing facts about this interesting creature of our ecosystem called the earthworm.

Interesting Facts About Worms:

👉 It belongs to the phylum Annelida

Earthworms belong to the phylum known as Annelida, which also includes polychaete worms and leeches.

More than 6000 species of earthworms can be seen worldwide, with about 180 species found in North America.

Also, more than a million earthworms can be seen on every acre of land.

👉 Earthworms are segmented animals.

Earthworms are segmented animals, with each of those segments containing its own set of nerves, muscles, and even excretory organs.

Also, these creatures of our ecosystem do not have ears, eyes, or lungs, but they have sensory receptors. These receptors allow them to detect their environment’s vibrations, light, and chemicals. Also, they don’t have any skeletons or bones.

👉 They can eat soil

Another interesting truth about earthworms is that they can eat the soil. They can crunch it up in their muscular stomachs, then digest what can be digested and ejects the rest part. Also, earthworms can consume almost ½ to 1 time of their own body weight per day.

Most of these worms live between 1 and 2 years. However, they may live up to eight years.

👉 Earthworms can contribute to soil fertility.

Earthworms have an incredible contribution to soil fertility. They can easily tunnel through the ground, eating their way through the soil.

Also, they can drag different plant debris and leaves down into the soil, enabling air to enter it and water and nutrients to drain through. Thus, these can eventually change the infertile, dense soil into fertile soil.

👉 The length of an earthworm

The length of an earthworm can vary among different species, ranging from less than just half an inch to almost 14 feet long. The largest earthworm was found in 1967 and was 22 feet long.

👉 Eating habits of earthworms

Earthworms are usually found in soil, where they consume various types of organic matter, such as nematodes, protozoa, bacteria, fungi, rotifers, and various other microorganisms, along with various types of plant matter.

Also, these creatures can survive in a wide range of soil conditions and types, from highly alkaline soils to incredibly acidic ones.

👉 The respiration procedure of earthworms

Earthworms can breathe or respire through their skin. It contains a double transport system that is made of coelomic fluid that can move within the fluid-filled coelom as a closed and simple circulatory system.

As earthworms do not have any specific respiratory organs, they can exchange gas through their moist capillaries and skin.

The oxygen gas is picked up by the hemoglobin that is dissolved in their blood plasma; in the same way, carbon dioxide is released. Salts, as well as water, can also be moved through the skin through active transport.

👉 The circulatory system of earthworms

These unique creatures have a dual circulatory system. In this, the closed circulatory system and the coelomic fluid carry the waste, food, and even respiratory gases. This closed circulatory system of earthworms has five main blood vessels. 

Those are the top or dorsal vessel, which mainly runs above the digestive tract, the subneural vessel that runs below the ventral nerve cord; the ventral or bottom vessel that runs under the digestive tract; and two later neural vessels that are present on either side of the nerve cord.

👉 The dorsal vessel of earthworms

The dorsal vessel of earthworms’ circulatory system is actually a collecting structure in the intestinal portion.

It can receive a pair of dorsal and commissural intestines in each segment. The ventral vessel of this system branches off to a pair of ventro-intestinals and ventro-tegumentaries in each segment.

Also, the sub-neural vessel offers a pair of commissural that runs along the posterior surface of the septum.

The pumping action of this dorsal vessel moves the blood forward, whereas the other four vessels carry the blood rearward. An earthworm’s blood has ameboid cells and hemoglobin mixed in the plasma.

👉 Earthworms are cold-blooded creatures.

Earthworms are cold-blooded creatures, and their blood is red in color. These interesting creatures can have between 1 and 5 pairs of hearts. Also, these annelids are 90% water, unlike humans, who have 75% water.

👉 Earthworms are hermaphrodites

These fascinating creatures are hermaphrodites, meaning each of these creatures carries both female and male reproductive organs.

When mating, two earthworms will exchange sperm and also fertilize each other’s eggs. Each of these creatures has both female and male genital pores.

As an invertebrate, these creatures lack a true skeleton. However, they can easily maintain their structure with the help of coelom chambers that are filled with fluid and hence, can function as a hydrostatic skeleton.

👉 The nervous system of earthworms

Earthworms’ Central Nervous System or CNS, consists of a bilobed brain, sub-pharyngeal ganglia, ventral nerve cord, and circum-pharyngeal connectives.

Earthworms’ brain has a pair of pear-shaped cerebral ganglia, which are situated in the dorsal segment of the third segment’s alimentary canal.

Besides this CNS, earthworms also have a peripheral nervous system where eight to ten nerves come out of the cerebral ganglia and support the buccal chamber, prostomium, and pharynx.

Also, three pairs of nerves support the second, third, and fourth segments, and three pairs support various structures of the segment.

👉 They can be used as bioindicators.

Earthworms are usually used as bioindicators of soil health because their absence and presence can provide significant information about the condition and quality of the soil.

Moreover, earthworms are used in scientific research because they are a common model organism for studying different aspects of biology, including evolution, ecology, and physiology.

👉 Earthworms’ body is divided into segments.

An earthworm’s entire body looks like a cylindrical tube-in-a-tube. This creature’s body is divided into a series of segments, also known as metameres.

Except for the mouth and anal part, each segment of an earthworm carries bristle-like hairs known as setae. These hairs anchor the body parts of an earthworm during movement.

Earthworms have special ventral setae that work to anchor mating earthworms.

👉 An adult earthworm has a clitellum.

An adult earthworm has a belt-shaped glandular swelling. This is called the clitellum, which usually covers this animal’s several body segments toward the front part. This is a vital part of the reproductive system and can produce egg capsules.

The posterior is cylindrical like the rest of the body, but as per the different species, it can be quadrangular, trapezoidal, octagonal, or flattened.

The last body segment of an earthworm is known as the periproct, which is the anus of this animal. A short vertical slit can be seen in this segment.

👉 The earthworm’s body is a tube of muscle.

An earthworm’s body is mainly like a tube of muscle arranged in two layers,vertically and horizontally. The procedure of tightening the horizontal muscle can force the head of this animal forward.

Then a wave of contractions passes back down its body, eventually squeezing of its body until the long muscles can take over and pull up the tail. In this way, earthworms can crawl both forward and backward in the soil.

👉 Their bodies have numerous sense organs.

The body of an earthworm is full of sense organs. For example, just a single segment of an earthworm has about 1900 sense organs.

These receptors give the animal a sense of touch, the ability to detect light, and the capacity to taste.

👉 They are attracted to one another by the scent.

These animals are attracted to each other by scent. Their mating procedure involves two worms lying head-to-tail and exchanging sperm while bound together in a mucus covering.

Also, an earthworm can carry up to 20 eggs which are sealed up and form a cocoon. This helps those eggs to survive in extreme conditions.

In favorable situations, earthworms can breed every seven to ten days, doubling their population in just 90 days.

Baby worms are hatched from cocoons, and usually, only one worm emerges from it.

👉 They are thin-skinned

Earthworms are thin-skinned animals; hence, they have no resistance to the sun’s ultraviolet radiation.

So, daylight for an hour can be very dangerous or even fatal to them. These animals will anchor their tail in their burrow and slither back into the earth if they hear any sudden noise.

Also, the eggs of earthworms can stay dormant in the soil for about 15 years and can wait for favorable conditions to support their life.

👉 Earthworms are detritivores

Earthworms are detritivores, meaning these animals eat decaying and dead plant and animal material. They break down these materials into smaller parts, vital for ecosystem nutrient cycling.

Also, earthworms fall prey to many birds and animals. However, the mole is their main predator. A mole can eat up to 50 earthworms in just a single day. Moreover, these amazing animals can regenerate the lost segments of their bodies.

So earthworms are interesting creatures that play a vital role in maintaining the health of ecosystems and soils. These animals are resilient and adaptable. 

At the end of this article, we learned about 20 really amazing facts about this remarkable animal called earthworms.

These facts offer us a clear picture of this unique animal of our ecosystem. To know more, you may visit our website.