Respiratory organs in earthworm

The earthworms’ skin has a wet feel to it. It’s for this reason that they’re known as slimy animals. The earthworm’s skin serves as its respiratory organ, which explains their wet skin. An earthworm’s skin is porous, allowing air to travel through readily. Gases are often exchanged through its wet skin and capillaries. The oxygen gas is taken up by the haemoglobin dissolved in the blood in these areas, and carbon dioxide is expelled.

Respiratory organs in earthworm

Earthworms are among the most underappreciated organisms on the planet. They’ve become ‘background music,’ along with our soils; we’re aware of them, but we don’t pay them any attention. Earthworms, on the other hand, are deserving of our attention since they are the engineers of our soils and perform an important role.

Earthworms are creatures that belong to Oligochaetes subclass, which makes up nearly half of the Annelida phylum’s members. There are around 3,000 earthworm species documented globally, with 27 species found in the United Kingdom, each with its unique ecological niche and needs. Earthworms, on the other hand, are understudied, and new species (and subspecies) are being discovered on a regular basis as DNA testing improves quantification.

Earthworms may be found on every continent and in every type of ecosystem, with the exception of deserts, where they require wet conditions to exist owing to their porous skins. Earthworms have both male and female reproductive organs, making them hermaphrodites. They are segmented and feature a body cavity (coelom) that serves as a hydroskeleton (i.e. a skeleton supported by fluid pressure). Earthworms breathe through their skin because they lack lungs or other specialised respiratory organs. The primary interior characteristics of an adult earthworm are depicted in the diagram below. Fully grown baby worms emerge from eggs. Within the first two or three months, they develop sex organs and achieve full size in approximately a year. They may live up to eight years, although the average lifespan is one to two years.

Earthworms glide by using retractable bristles to grab the ground. All segments contain eight bristles, with the exception of the first. Worms may also change their direction of motion by leading with their tail.  Burrowing is accomplished by shoving the front end into a fissure and then expanding the gap with the rest of the body. In the process, large amounts of dirt are swallowed, which are combined with mucus as they move through the stomach and reused to plaster the tunnel walls, making a line. A face casting is formed when excess material is extruded on the ground surface.

Earthworms are beneficial to environment

They are the primary source of soil enrichment and improvement for plants, animals, and even people. Burrowing earthworms aerate the soil by creating tunnels, allowing air, water, and nutrients to penetrate deeper into the soil. Earthworms devour organic stuff like rotting plants or leaves in the soil. This organic substance is inaccessible to plants. The earthworm excretes excrement called castings after digesting organic substances. Many nutrients that the plant can need can be found in the castings.

Anatomy of an Earthworm

1. Body with Segments

Annelida, or Annelids, is the phylum in which earthworms are classified. Annelida means “small rings” in Latin. The earthworm’s body is segmented, resembling numerous little rings linked or fused together. The earthworm has between 100 and 150 segments. The body’s divided portions provide crucial structural tasks. The earthworm may move more easily if it is segmented. Setae are muscles and bristles that cover each segment or portion.

2. Earthworms are categorised as Annelida, or Annelids, in the phylum Annelida. In Latin, Annelida means “little rings.” The body of an earthworm is segmented, resembling a series of little rings joined or fused together. Between 100 to 150 segments make up the earthworm. The bristles, or setae, help anchor and manage the worm as it travels through mud. The worm’s body is partially entrenched in the earth, while the remainder of it protrudes forward.

3. System of digestion

The digestive system is divided into several areas, each of which serves a specific purpose. The dirt next goes via the oesophagus, which contains calciferous glands that produce calcium carbonate to remove excess calcium from the earthworm’s body. The food moves into the crop, where it is stored, after passing via the oesophagus, and then into the gizzard. The gizzard grinds the meal thoroughly using stones that the earthworm consumes. 

4. System of Circulation

The circulatory system is another important organ system. The earthworm’s circulatory system is closed. The blood supply to the earthworm’s organs is provided by three major channels. The aortic arches, dorsal blood vessels, and ventral blood vessels are these vessels. The aortic arches work in the same way as the human heart does. The aortic arches are made up of five pairs and are responsible for pumping blood into the dorsal and ventral blood arteries. The dorsal blood arteries are in charge of transporting blood to the earthworm’s front.

5. System of the Respiratory System

Earthworms don’t have lungs, hence they can’t breathe. They inhale and exhale via their skin. Diffusion allows oxygen and carbon dioxide to travel through the earthworm’s epidermis. The earthworm’s skin must be maintained wet in order for dispersion to take place. To keep its skin wet, body fluid and mucus are secreted. Earthworms, on the other hand, require wet or moist soil. This is one of the reasons they prefer to come out at night, when the temperature is likely to be colder and the “evaporating potential of the air” is lower. Even though they can’t sight, earthworms have gained the capacity to detect light.

Reproduction of Earthworms

Earthworms are hermaphrodites, meaning they have both male and female reproductive organs. Each earthworm’s male and female sex organs may generate sperm and eggs, respectively. Two worms lineup inverted from one another during mating to exchange sperm. Each earthworm has two male apertures and two sperm receptacles that accept sperm from a different partner. A slime tube will grow around the clitellum, which will fill with albuminous fluid. The earthworm will exit the slime tube by moving ahead. The slime tube will pass over the female pore when the earthworm goes through it, scooping up eggs. The tube will proceed down the earthworm, passing through the spermatheca, which contains the stored sperm known as the spermatozoa. As the worm crawls entirely out of the slime tube, the eggs will fertilise and the slime tube will shut. The slime tube will be shaped into a “egg cocoon” and placed in the ground. Young worms will grow from the fertilised eggs.

Conclusion 

The earthworms’ skin has a wet feel to it. It’s for this reason that they’re known as slimy animals. The earthworm’s skin serves as its respiratory organ, which explains their wet skin. Earthworms may be found on every continent and in every type of ecosystem, with the exception of deserts, where they require wet conditions to exist owing to their porous skins.