Respiration is a vital function for all living beings, since even plants do it. In the animal kingdom, the difference in the types of breathing lies in the anatomical adaptations of each animal group and in the type of environment where they live. The respiratory system is made up of a set of organs that act in unison to exchange gases. During this process, a gas exchange basically takes place between the body and the environment where oxygen (O2), an essential gas for vital functions, is obtained and released carbon dioxide (CO2), and this last step is vital, as it is deadly if it accumulates in the body.
If you are interested in learning about the different types of animal respiration, keep reading this article on our site where we will tell you about the different ways in which that animals breathe and their main differences and complexities.
Respiration in the animal kingdom
All animals share the vital function of respiration, but how they do it is a different story in each animal group. The type of breathing they use will vary depending on the animal group and its anatomical characteristics and adaptations.
During this process, animals, like other living beings, exchange gases with the environment and can obtain oxygen and get rid of carbon dioxide. Thanks to this metabolic process, animals can obtain energy to be able to carry out all other vital functions, and this is essential for aerobic organisms, that is, those that They live in the presence of oxygen (O2).
Types of animal respiration
There are various types of respiration in animals, which we could summarize in:
- Pulmonary respiration: which is carried out by the lungs. These can be anatomically different between animal species. Similarly, some animals only have one lung, while others have two.
- Gill Respiration: This is the type of respiration that most fish and marine animals have. In this type of respiration, gas exchange takes place through the gills.
- Tracheal respiration: This is the most common type of respiration in invertebrates, especially insects. Here, the circulatory system does not intervene for gas exchange.
- Skin respiration: Skin respiration occurs mainly in amphibians and other animals located in humid areas and with thin skin. In skin respiration, as the name suggests, gas exchange takes place through the skin.
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Lung respiration in animals
This type of respiration, where gas exchange takes place through the lungs, is widespread among terrestrial vertebrates (such as mammals, birds and reptiles), aquatic (such as cetaceans) and amphibians, which can also breathe through their skin. Depending on the group of vertebrates, the respiratory system has different anatomical adaptations and the lungs change their structure.
Lung respiration in amphibians
In amphibians, the lungs can be simple vascularized sacs, such as those of salamanders and frogs, which are seen as lungs divided into chambers with folds that increase the gas exchange surface: the flaveoli.
Pulmonary respiration in reptiles
On the other hand, reptiles have more specialized lungs than amphibians. They are divided into numerous spongy air sacs that are interconnected. The total gas exchange surface increases much more than in amphibians. Some species of lizards, for example, have two lungs, but in the case of snakes, they have only one.
Lung respiration in birds
In birds, on the other hand, more complex respiratory systems are seen due to the function of flight and due to the high demand for oxygen that it entails. Their lungs are ventilated by air sacs, structures present only in birds. The sacs are not involved in gas exchange, but they have the ability to store air and then expel it, that is, they act like bellows, which allows the lungs to always have reserves of fresh airthat flows inside.
Mammalian pulmonary respiration
Mammals have two lungs with elastic tissue divided into lobes, and their structure is similar to a tree, as they branch out into bronchi and bronchioles to the alveoli, where gas exchange takes place. The lungs are housed in the chest cavity and are limited by the diaphragm, a muscle that helps them and that with its distension and contraction facilitates the entry and exit of gases.
In this other article, we show you examples of Animals that breathe through their lungs.
Gill respiration in animals
Gills are the organs responsible for breathing under water, they are external and are located behind or to the side of the head depending of the species. They can appear in two forms: as grouped structures in the gill slits or as branched appendages, such as in newt and salamander larvae, or in invertebrates such as the larvae of some insects, annelids and molluscs.
The water that enters through the mouth leaves through the cracks, the oxygen is “trapped” and transferred to the blood and the rest of the tissues. Gas exchange occurs thanks to the same water current or with the help of the operculum, which conducts water to the gills.
Animals that breathe through gills
Some examples of animals that breathe through gills are:
- Giant Manta (Mobula birostris).
- Whale shark (Rhincodon typus).
- Pouch Lamprey (Geotria australis).
- Giant clam (Tridacna gigas).
- Great Blue Octopus (Octopus cyanea).
For more information, you can consult this other article on our site on How do fish breathe?
Tracheal respiration in animals
Tracheal breathing in animals is most common in invertebrates, mainly insects, arachnids, myriapods (centipedes and millipedes), etc. The tracheal system is made up of a branch of tubes and ducts that run through the entire body and connect directly with the rest of the organs and tissues, so in this case, does not intervene circulatory system in the transport of gases. In other words, oxygen moves without reaching the hemolymph (liquid from the circulatory system of invertebrates such as insects, which performs a function analogous to blood in humans and other vertebrates) and enters directly into the cells. In turn, these ducts connect directly to the outside through openings called stigmata or spiracles, through which it is possible to expel CO2.
Examples of tracheal breathing in animals
Some of the animals that breathe through tracheal breathing are:
- Water Bunting (Gyrinus natator).
- Grasshopper (Caelifera).
- Ant (Formicidae).
- Bee (Apis mellifera).
- Asian hornet (Vespa velutina).
Skin respiration in animals
In this case, respiration occurs through the skin and not through another organ such as lungs or gills. It mainly occurs in some species of insects, amphibians and other vertebrates associated with humid environments or with very thin skins, such as mammals such as bats, which have very thin skin on their wings and through which gas exchange can take place. This is very important, since through a very thin and irrigated skin gaseous exchange is facilitated, and in this way, both oxygen and carbon dioxide carbon can freely pass through it.
In some cases, such as certain species of amphibians or softshell turtles, they have mucous glands that help keep their skin moist. Also, for example, other amphibians have folds in their skin, and thus increase the exchange surface, and although they can combine ways of breathing, such as lung and skin, 90% of amphibians perform gas exchange through the skin.
Examples of animals that breathe through their skin
Some of the animals that breathe through their skin are:
- Common earthworm (Lumbricus terrestris).
- Medicinal leech (Hirudo medicinalis).
- Iberian newt (Lissotriton boscai).
- Spodefoot Toad (Pelobates cultripes).
- Common Frog (Pelophylax perezi).
- Sea urchin (Paracentrotus lividus).
