Mary Allen
Introduction: Aquatic animals with lungs
When we think of aquatic animals, we often imagine creatures with gills that extract oxygen from water. However, there are some aquatic animals that have evolved to breathe through lungs. These animals have adapted to extract oxygen from air instead of water, making them unique in the aquatic world.
Anatomy of lung-breathing aquatic animals
Lung-breathing aquatic animals have developed lungs that are similar to those of terrestrial animals. These lungs have a large surface area for gas exchange and are lined with blood vessels that allow oxygen to diffuse into the bloodstream. In addition to lungs, these animals may also have gills, which they can use to extract oxygen from water.
The axolotl: A salamander that breathes air
The axolotl is a salamander that is native to Mexico. It is known for its ability to regenerate limbs and organs, but it is also unique in that it breathes air. While it has gills, the axolotl can also come to the surface to breathe air through its lungs. This allows it to survive in low-oxygen environments and to explore both land and water.
The African lungfish: A unique fish
The African lungfish is a fish that is found in the rivers and swamps of Africa. It is unique in that it has both lungs and gills, allowing it to breathe both air and water. The lungfish can survive in environments with low oxygen levels by coming to the surface to breathe air through its lungs. It can also aestivate, a state of dormancy similar to hibernation, during times of drought.
The Australian lungfish: A living fossil
The Australian lungfish is a living fossil that is found in the Australian rivers. It is similar to the African lungfish in that it has both lungs and gills, but it is more closely related to the ancient fish that lived over 300 million years ago. The Australian lungfish can survive in environments with low oxygen levels by coming to the surface to breathe air through its lungs.
The mudskipper: A fish that can live on land
The mudskipper is a fish that is found in the mudflats and mangroves of the tropics. It is unique in that it can breathe air through its skin and the lining of its mouth. This allows it to survive in environments with low oxygen levels and to move around on land. The mudskipper can also use its fins to climb trees and rocks.
The gills-to-lungs transformation
The evolution of lung-breathing aquatic animals is thought to have started with the transformation of gills into lungs. This transformation allowed these animals to extract oxygen from air instead of water, which was beneficial in environments with low oxygen levels. Over time, these animals developed more efficient lungs and were able to survive in a wider range of environments.
How lung-breathing helps aquatic animals
Lung-breathing allows aquatic animals to survive in environments with low oxygen levels and to explore both land and water. It also allows them to move between different bodies of water without having to change their breathing apparatus. Lung-breathing may have also played a role in the evolution of certain characteristics, such as the ability to regenerate limbs.
The challenges of lung-breathing in water
Breathing through lungs in water presents some challenges for aquatic animals. The air in their lungs is less dense than water, which makes it harder for them to stay submerged. They also have to be careful not to inhale water, which can be deadly. In addition, lung-breathing requires more energy than gill-breathing, which means that these animals may need to eat more frequently.
The importance of preserving lung-breathing species
Lung-breathing aquatic animals are important in maintaining the biodiversity of our planet. They have unique characteristics and adaptations that make them valuable for scientific research. In addition, they are often indicators of the health of aquatic ecosystems. Preserving these species is crucial for maintaining the balance of our planet’s ecosystems.
Conclusion: The wonders of lung-breathing aquatic animals
Lung-breathing aquatic animals are a fascinating group of creatures that have evolved to breathe air instead of water. From salamanders to fish, these animals have adapted to survive in low-oxygen environments and to explore both land and water. Understanding the anatomy and behavior of these animals can help us appreciate the diversity of life on our planet and the wonders of evolution.
References and further reading
- Neil H. Shubin. Your Inner Fish: A Journey into the 3.5-Billion-Year History of the Human Body. Vintage, 2009.
- N. Justin Marshall, Thomas W. Cronin, and Eric J. Warrant. "Visual adaptations in crustaceans: spectral sensitivity in diverse habitats." Visual Ecology. Princeton University Press, 2014. 345-362.
- Richard Dawkins. The Ancestor’s Tale: A Pilgrimage to the Dawn of Evolution. Mariner Books, 2016.
- "Lungfish." Encyclopedia Britannica. https://www.britannica.com/animal/lungfish. Accessed 17 May 2021.
- "Axolotl." Encyclopedia Britannica. https://www.britannica.com/animal/axolotl. Accessed 17 May 2021.
- "Mudskipper." Encyclopedia Britannica. https://www.britannica.com/animal/mudskipper. Accessed 17 May 2021.