Animals in metamorphosis
A, in zoology, consists of a transformation experienced by certain animals through which they pass from one form to another, in regular succession, from birth to adulthood. This is part of their biological development and affects not only their physiology, but also their behavior and lifestyle.
- In this peritoAnimal article.
- We will explain which animals undergo a metamorphosis during their development.
- Also detailing what the metamorphosis phases are like or what types of metamorphosis exist.
- Read on and find out all about this process!.
To better understand what “metamorphosis” means, it is necessary to know its etymology. The term derives from Greek and is composed of the following words: meta (beyond), morph (figure or form) and -osis (change of state), so it would be a transformation from one element to another.
Therefore, metamorphosis in animals is a sudden and irreversible change in physiology, morphology and behavior. It is a period of the life of an animal that corresponds to the transition from a larval to a juvenile or adult form. It affects insects, some fish and some amphibians, but not mammals.
This stage of development is characterized by the birth of an autonomous larva, unable to reproduce sexually before reaching its youthful or adult stage, called “imago” or “last stage”. In addition, metamorphosis phenomena are not only superficial, but also involve extremely profound changes in animals, such as:
Now that you know what metamorphosis is, we’ll explain what types exist. However, you should know that, while in insects there is a change at the cellular level, in amphibians this implies a change in the tissues of the animal, so these are different processes. Find out below the differences between the two insect metamorphosis and how they differ from amphibian metamorphosis:
We have observed two types of metamorphosis in insects, unlike amphibians, which only suffer one. Here’s what they’re all about:
In insects, metamorphosis is controlled by “ecdisone”, a steroid hormone that has no juvenile hormones and plays a fundamental role in maintaining larval characteristics in the animal’s body. However, there is a growing problem: several insecticides have characteristics similar to these juvenile hormones, so they end up preventing the individual’s metamorphosis by inhibiting them altogether.
“The metamorphosis of amphibians is the result of the action of thyroid hormone. (Gudernatsch, 1912) Experience shows that a thyroid transplant or thyroid treatment causes a metamorphosis.”
In the metamorphosis of amphibians, we notice some similarity with the insects, since they also go through a larval phase (tadpole) and a nymph phase (tadpole with limbs) before giving birth to the imago, which would be the adult state. The most common example is the frog.
After the “prométamorphosis” phase, when the animals’ fingers become visible, an interdigital membrane called palm connects them to form the paddle-shaped swimming leg. The hormone called the pituitary gland then passes through the bloodstream to the thyroid. At this point, it stimulates the production of the hormone thyroxine T4, which causes a complete metamorphosis.
Next, we’ll show how metamorphosis phases occur in different types
To better understand simple or incomplete metamorphosis, we will show the example of grasshopper metamorphosis. It is born from a fertile egg and begins to develop gradually, without going through a phase of chrysalis. In the first steps, without wings, as they will appear later, as you evolve. In addition, it is not sexually mature until it reaches adulthood.
To explain complete or complicated metamorphosis, we chose butterfly metamorphosis. It begins, as in the previous case, from a fertile egg, which hatches into caterpillars. This individual will eat and develop until the hormones begin to cause a phase change. The caterpillar will begin to curl with a thread that secretes itself, to form a chrysalis that completely covers it.
During this period of apparent inactivity, the caterpillar will begin to reabsorb its juvenile organs and completely transform its body until it develops legs and wings. This can last for days or weeks. Finally, the chrysalis will open up, giving way to an adult butterfly.
To explain the stages of metamorphosis in amphibians, we chose frog metamorphosis. Frog eggs are fertilized in water, while surrounded by a gelatinous mass that protects them. They will grow until the larvae are fully formed, and then the tadpole, which has head and tail, will be born. As the tadpole feeds and evolves, it will begin to develop legs and, over time, the silhouette of an adult frog. Finally, when she loses her tail, she will be considered an adult and sexually mature frog.
Finally, we show a partial list of zoological groups of animals that undergo a metamorphosis during their development:
If you want to read more articles similar to Animals that are metamorphosing, we recommend that you visit our Curiosities of the Animal World section.