THE FASCINATING LIFE CYCLE OF AXOLOTLS

Today we are going to talk about one of the most interesting animals in the world, the axolotl. They are being studied by scientist for many different reasons. Despite being known as Mexican walking fish, they are amphibians related to the tiger salamander. However, they aren’t just as any other salamander, they are neotenic, which means that they don’t develop adult characteristics. As they never go through metamorphosis, they remain aquatic creatures even in their adulthood. Keep reading, and I go more in depth about some of the topics that I’ve introduced so far.

Photo by: Scazon
https://creativecommons.org/licenses/by/2.0/

If you take a look at the photo, you can see that axolotls have some characteristics which aren’t present in regular adult salamanders. They retain features from the larval period throughout all their lives. Unlike salamanders, they have external gills with filaments, a caudal fin, gill slits under the external gills and they eat by suction, as they don’t have fully developed teeth. This is called paedomorphism and it means that they retain juvenile or larval features during their life. But, why do they never completely develop?

As I mentioned in the introductory paragraph, axolotls are neotenic salamanders but what does that mean? Neotenic animals experience a slowing in their physical development while their sexual development occurs at a normal speed. When the sexual maturity is reached, physical development is stopped and never completed. This phenomenon is linked to a lack of thyroid stimulating hormone and is thought to be a survival mechanism. In the aquatic environments and in a juvenile state, less food is needed. Metamorphosis and full adult development can be induced by iodine shots or injections.

Photo by: Iñaki RT
https://creativecommons.org/licenses/by-sa/2.0/

Axolotls are subjects of many studies for many reasons that intrigue scientists. They have an awesome transplant acceptance, being able to use transplanted parts at their full potential very soon after the surgery. This is studied for its medical application in humans. Another amazing characteristic is their extremely effective regeneration capacity. They can regenerate, instead of scarring, parts of almost all the tissues including the nervous system. 

For all their amazing abilities, their interesting features and how useful they could be for medical research, axolotls are fascinating animals. They seem to defy laws of biology and that makes them unique.