You’re probably wondering: Do fish have lungs?
It’s a complicated question, and the answer isn’t always yes or no. Generally, no. Let’s take a look at why.
There are several varieties of fish, many having adapted to the modern environment. Whilst most of the fish leaned towards a particular manner of breathing, some other fish did tend to adapt differently.
So, while most of us do think that fish have only one way of breathing, that is not true. Let us understand the general manner and the exceptions in this blog.
How Do Fish Generally Breath?
Fish generally breathe by taking in water through their mouths. The oxygen is then absorbed, and carbon dioxide is released.
The oxygen is then transferred throughout the body, while the carbon dioxide is released into the water via a process called exhalation.
What Organ Helps Fish Breath?
Most fish have gills, paired organs behind their heads. These delicate filaments are made up of a series of thin gill arches that contain blood vessels and capillaries (tiny blood vessels).
Blood flows through the capillaries, which absorb oxygen from the water. As you might imagine, this requires a lot of energy on an animal’s part.
Generally, fish do not have lungs. Their gills are the organs that extract oxygen from water, which helps them breathe.
The gill’s filaments are lined with blood capillaries that deliver oxygen-rich blood to the tissue.
The lamellae are tiny structures that function as filters, trapping dissolved oxygen molecules and allowing water to flow freely past them.
A current of water is pulled through the gills, and oxygen is exchanged for carbon dioxide in cells lining the gills.
The blood capillaries are located between these cells, so when oxygen is exchanged for carbon dioxide, it is carried back to the rest of the body via these tiny blood vessels.
Are Gills The Only Way Fish Breath?
Are gills the only way fish breathe? No. Along with gills, fish have a number of other ways to breathe.
Fish that live in water need to be able to take in oxygen from the water and get rid of carbon dioxide. There are three different ways this can happen:
a) by breathing through their gills
b) by absorbing oxygen directly into their bodies through their skin which is usually in younger fish whose gills are not yet developed.
c) by absorbing oxygen through a modified lung (in lungfish) which helps them survive in times when there is no water.
d) Having a labyrinth organ which helps breathe air and convert it into oxygen. The betta fish are classic examples of labyrinth breathers.
e) Buccal Pumping in Sharks where the sharks can remain still and yet breathe.
The first two methods are similar for many fish. This has been discussed in the article:
The third method is unique to lungfish. The fourth is another type. The last type is found in sharks and a few other rare types of fish.
Let us discuss these three types here.
Are There Fish That Have Lungs?
If you’ve ever heard the word “lungfish,” you may have assumed it was a fish with lungs. Well, you’re right. There are six types of lungfish that live in freshwater habitats around the world.
The lungfish is the only species of fish that has lungs. Lungfish have gills, which they use to breath underwater.
The lungfish also have lung that are biologically adapted to help them breathe when they are at the surface. They are able to absorb oxygen from the air, through which they can survive for months.
What Is Labyrinth Breathing?
Labyrinth fish are a group of freshwater fish that have evolved the ability to breathe air.
Their respiratory organs, called labyrinths, are located above the gills and are extensions of the first gill arch.
Labyrinths contain complex, folded, bony structures covered with respiratory epithelium (the labyrinth organ).
The labyrinth organ allows them to breathe air from above their water source.
This adaptation is common in betta fish, but it also occurs in other families of fish including Anabantoidei.
What is Buccal Pumping?
Buccal pumping is the process by which sharks breathe without moving, which allows them to stay still for long periods of time.
While many animals can breathe underwater through their gills, sharks are one of only a few species that can breathe through their mouths.
This means that they must swim constantly to keep their bodies oxygenated.
However, many species of shark have evolved to allow them to take in air without swimming around.
In addition to being an efficient way to conserve energy and reduce movement, this ability also provides them with greater energy to hunt while they sleep or rest on the floor of an ocean basin.
Buccal pumping works by forcing water over their gills while simultaneously taking in oxygen through their mouths.
Difference Between Lungfish And Labyrinth Fish
Lungfish and labyrinth fish are two kinds of fish that have different ways of getting oxygen. Both kinds of fish have gills, which are organs that take in water and allow the fish to breathe.
Lungfish manage without water. They have biologically modified lungs, or air sacs, inside their bodies. They use these lungs when not in water when they need to get air.
Labyrinth fish use the organ when oxygen is low in water. But they still need to remain in water.
A Few Fish Use Their Skin To Breath?
Fish use their skin to breathe in the early stages of their development. In fact, some fish use their skin to breathe until their gills develop.
Hence these gills need to be fully developed.
This is because, generally, fish rely on gills for breathing instead of lungs. The lung fish and labyrinths are only exceptions.
In conclusion, we’ve seen that fish have a number of different ways to breathe.
Gills are the most common way for aquatic animals to get oxygen, but lungfish also have lungs, and some even have a special organ that lets them breathe air directly from the surface which is the labyrinth organ.
Fish can also use buccal pumping to move water over their gills.
But do you know what else? This is only one small part of the amazing world of fish!
There’s so much more to learn about these fascinating animals, so be sure to check out our other blog posts on this topic.