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Respiration in Cockroach and Earthworm

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Introduction of Respiration in Cockroach and Earthworm


The predecessor of the respiratory organs of birds, mammals and man is found in the arthropods and most primitive invertebrates, and perhaps in molluscs. This stage of evolution is called metamorphosis. In molluscs, the air sacs, or gills, were a means of respiration and it was not until the evolution of the vertebrates that it became an end in itself. The importance of respiration to primitive animals and early vertebrates was generally unknown. The study of the lung in insects, which is often mentioned in texts, was mistaken for respiration. 


The cockroach is the main component of any termite colony. They form large, eusocial colonies and form waste disposal systems for their food. Their waste products, carbon dioxide and water are returned to the environment through their respiratory system. The knowledge about their respiration is important for our understanding of the biology of these insects. The respiration of cockroaches is a process that must be explained to understand the life cycle of these insects. This study will also provide a useful basis for breeding cockroaches for their eventual use in the biotech and pharmaceutical industries. 

There are three important anatomical parts of the respiratory system of insects and arachnids, which all utilize the gas exchange between two compartments. 

Respiration of Earthworm: The respiratory system of the earthworm consists of a thin and smooth muscular body, with different sensory organs, including tracheae, spiracles, and cerci. 

The information from these organs is transmitted to the nerve cells in the pharynx and the chordotonal organ, which are the sensory appendages of the gut. Respiration of Insects: The respiratory system of the insects consists of a long, tubular body with tracheal tubes, spiracles, and cerci. 

The respiratory process in insects involves the movement of both the tracheal tubes and the respiratory organs, like spiracles and cerci. 

The internal organs and the tracheae of insects are secretory organs and are responsible for the production of food. The spiracles and cerci are the respiratory organs that move air in and out of the tracheae, with the aid of cilia, which are produced from the first abdominal ventral plates. The tracheae of insects are mostly made up of muscle, which does not contain an epithelium. Because of cockroaches, insects, and all other forms of life on the earth, their breathing systems are described as spiracles or tracheae. The Tracheae: Spiracles, tracheal tubes and cerci are sensory appendages of the gut. The spiracles help insects with moving air in and out of the tracheae.

How Do Cockroaches Breathe?

The respiratory system in insects differs from that of humans. Here, we will learn about the respiration of cockroaches, which is black or brown coloured insects and live in damp places. It is omnivorous and feeds on small insects, food grains, cereals, other plants, and animal products; so, they consume any organic matter.

What Type of Respiration Do Cockroaches Have?

Their respiratory system is interesting and different, the respiratory organ of cockroaches is a tracheal system. The trachea is a tubular structure also known as a windpipe helping to conduct the air. It takes oxygen from the air in the surroundings; insects including cockroaches have a network of tracheal tubes connected with each other and this is termed the tracheal system.

How Does a Network of Trachea Work?

There are different parts of the tracheal system that work together for respiration in cockroaches, explained as follows-


These are small holes present on the lateral surface of the main body. These are open to the air and present as openings just like nostrils in humans. So, the air is taken in with the help of spiracles that travels through the tracheal tube. The opening of spiracles is regulated by muscular sphincters. When sphincters open, air comes in and when they close, air does not enter the holes.


These are tube-like structures that open through spiracles and this part carries oxygen from the air (received from spiracles) to other body parts.


These are subdivided parts from the trachea that appear thinner tube-like structures. Tracheoles have a network of fluid (hemolymph) and these are the sites where gaseous exchange takes place by the process of diffusion.

The concept of the respiratory system of a cockroach is similar to that of human beings in a way that spiracles act as nostrils, the trachea is common in both and tracheoles act as bronchioles and alveoli in humans.

Respiration in Earthworm

Earthworms are slimy creatures and are segmented in appearance; these are found in soil and help in maintaining soil fertility. They rely on the live and decayed organic matter under the soil. Respiration in earthworms is through the skin.

How Do Earthworms Breathe?

Learning about earthworms, they perform the process of respiration with the help of thin permeable skin. Oxygen will not move directly through the skin, it mixes with the moist slime first before entering the skin. Therefore, it is necessary for earthworms to have moist skin to prevent suffocation. Under the surface of the skin, there are blood capillaries where also the mixture of slime and air reaches. Besides skin and capillary, there are blood vessels in earthworms and the dorsal blood vessels take the oxygen to the head region (anterior region) whereas the ventral blood vessels take it to the posterior region. This way, oxygen is circulated throughout the body. Earthworms have become a common food item in North America. Earthworms are part of a diet that includes chicken, beef, pork, fish, and vegetables and fruit.

How Do Earthworms Respire and Perform Exhalation?

Earthworm respiratory systems are not one-sided; Now, it’s time to know about carbon dioxide or the waste gases coming out of the earthworm’s body. As we know, the body of an earthworm is divided into a number of segments, and segmentation is performed by numerous septa. There are nephridia present in the segments of the earthworm’s body that help in exhalation.

What is the Respiratory Organ for Earthworms?

Earthworms have no specialized organs for respiration. However, all segments of the body possess nephridia except the first three anterior segments and the last posterior segment. Nephridia are coiled tubular duct-like organs in earthworms to filter and remove waste from their bodies. They consist of openings that are extended till the skin and each segment can throw out waste gases through these openings present in the skin of earthworms.

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FAQs on Respiration in Cockroach and Earthworm

1. How do cockroaches breathe? Do they have lungs similar to us?

A cockroach’s body is divided into three sections: head, thorax and abdomen. Small openings called spiracles are present in their bodies through which the exchange of gases takes place. A network of air tubes is present in their body, known as the tracheal system with the trachea and tracheoles, for gas exchange. During inspiration, oxygen rushes through spiracles to the trachea and then reaches to every cell and tissue of the body. Similarly, carbon dioxide moves through the tracheal tubes and moves out through the spiracles. So, cockroaches do not have lungs but have a solid respiratory system, somewhat similar to humans.

2. How many spiracles are there in the respiratory system of a cockroach?

There are 10 pairs of spiracles on the lateral sides of the cockroach body that are guarded by hairs or bristles, i.e. there are a total of 20 spiracles. Spiracles are openings as holes regulated by the sphincter. The bristles avoid the entry of pathogens or dust particles. 

3. What is the tissue fluid present in cockroaches?

The tissue fluid present in cockroaches is called hemolymph and it flows freely inside its body, touching all internal tissues and organs. It is mixed up with 90% of watery fluid, thus making up 10% of hemocytes.

4. Explain the earthworm’s respiratory system.

Earthworm’s respiratory system performs exchange of gases through the moist skin and capillaries where oxygen is in the dissolved form in the blood plasma and carbon dioxide is released through nephridia openings present in the segments of its body. The body surface is the respiratory surface where an exchange of gases like oxygen and carbon dioxide takes place between blood capillaries of outer epidermis and surface filled with moisture contributed by secreted mucus and excreted fluids.

5. How is the skin of earthworms always moist?

The skin of earthworms is kept very moist because of the secretion of mucus from its epidermis and also it possesses excretory pores that release body fluids. These body fluids mixed with plasma act as respiratory pigments. Moist skin helps in picking up oxygen from the air thus playing an important role in the earthworm respiratory system. Oxygen diffuses in and Carbon dioxide diffuses out of the moist skin to complete the process of respiration in earthworms.

6. Do earthworms breathe or not?

Earthworms do not have a breathing organ but they can extract oxygen from the air in which they are found. They are however wonderful examples of breathing. Earthworms are found in the soil. The earthworm's body is made up of oxygen absorbers which trap the oxygen from the air, using them as its respiratory system. So, the worms which are present in soil and below the soil surface can breathe oxygen just like the surface-dwelling human. Earthworms are very good for the soil, removing a large number of harmful soil particles. They can also be used to speed up the process of decomposition of organic matter in the soil and hence improve the fertility of the soil.

7. Do earthworms eat plastic?

Earthworms cannot eat plastic because it does not have any nutrients. It has no food value for the worms to eat. The worms are only damaged by the plastic that they crawl in. Worms have tiny mouthparts. They can neither chew nor swallow plastic. Earthworms are negatively affected by plastic. The material can sometimes prevent the worms from coming out of the soil and cause the death of the worms due to suffocation or dehydration. Moreover, plastic is not a nutritional source for worms and it also poses a risk of the worms contracting the disease from coming into contact with it.

8. Why are worms important for the soil?

The earthworm is a key component of the soil. Worms create aeration of the soil. The worms feed on the dirt and make the soil rich in nutrients. Earthworms are like workhorses of the soil. The worms help plants to break down decaying organic matter, which helps new organic matter enter the soil. Worms are important for soil productivity. Soils are rich in organic matter. Soils are the home of worms and soil is rich in the nutrients that earthworms need to survive.

9. Can the earthworms be considered pests?

Yes, earthworms can be considered pests when they eat or invade large amounts of your lawn. Eating and invading large amounts of lawns reduces the effectiveness of chemicals applied to combat weeds. When the earthworms eat too much, they not only reduce the effectiveness of chemical control, but they also compete with your lawn grass for nutrients, water and sunlight. If you are concerned about the use of chemicals, you can prevent earthworms from turning your lawn into a carpet by installing a blanket barrier around your plants.

10. What types of diseases does an earthworm have?

Earthworms can have different kinds of diseases that can lead to the worm's death. These can include viral infections such as Mysore, which is caused by the parasitic soil nematode. They can also be caused by bacteria, fungi and protozoa (single-celled animals).because of earthworms ' sedentary lifestyle, they're very prone to diseases and are often more susceptible to bacteria and protozoa. because of earthworms ' habitat, they are constantly in contact with their 'endocrine glands' and can develop problems. For example, earthworms have a very sensitive nervous system and infection can cause them to become weaker, leading to an early death.