Content
- What is metamorphosis?
- Types of metamorphosis
- insect metamorphosis
- Amphibian metamorphosis
- Phases of simple metamorphosis
- Stages of complete metamorphosis in insects
- Stages of metamorphosis in amphibians
- Which animals have metamorphosis?
THE metamorphosis, in zoology, consists of a transformation that certain animals experience through which they pass from one form to another, in regular succession, from birth to adulthood. is part of your biological development and it doesn't just affect your physiology, but also your behavior and lifestyle.
In this article by PeritoAnimal, we'll explain what the animals that undergo metamorphosis in their development, also detailing how the phases of metamorphosis are or what types of metamorphosis exist. Keep reading and find out all about this process!
What is metamorphosis?
To better understand what it means "metamorphosis’, we must know your etymology. The term derives from Greek and is composed of the following words: goal (in addition), morphe (figure or shape) and -osis (change of state), therefore, would be a transformation from one element to another.
Thus, the metamorphosis in animals is a sudden and irreversible change in physiology, morphology and behavior. It is a period in an animal's life that corresponds to the passage from a larval form to a juvenile or adult form. It affects insects, some fish and certain amphibians, but not mammals.
This stage of development is characterized by the birth of an autonomous larva, unable to reproduce sexually until reaching its juvenile or adult stage, known as "imago" or "last stage". Furthermore, the phenomena of metamorphosis are not only superficial, but also involve extremely profound changes in the animal, such as:
- Organ modification
- Organic tissue modification
- Adapting to a new environment
Types of metamorphosis
Now that you know what metamorphosis is, we'll explain what types there are. However, you should know that, while in insects there is a change at the cellular level, in amphibians it involves a modification in the animal's tissues, so these are different processes. Find out below what differences exist between the two insect metamorphoses and how it differs from amphibian metamorphosis:
insect metamorphosis
we observe in insects two types of metamorphosis, unlike amphibians, who experience only one. Next, we'll explain what they consist of:
- hemimetabolism: also known as simple, easy, or incomplete metamorphosis. In this type of metamorphosis, the individual does not experience the "pupa" phase, that is, he does not have a period of inactivity. It feeds constantly, thus increasing its size, until it reaches its adult stage. Within a species, each life form has its own adaptation to the environment. Some examples of animals that suffer hemimetabolism are lobsters and bedbugs.
- Holometabolism: It is also known as complete or complicated metamorphosis. In this case we observe several different stages and all end in the pupal stage (which can last weeks and even years, depending on the species) until the birth of the imago. We see a radical change in the aspect of the individual. Some examples of animals that undergo holometabolism are the butterfly, the fly, the mosquito, the bee or the beetle.
- ametabolism: also called "ametabolia", it refers to insects and arthropods that, when they reach the nymph stage, present certain similarities with the adult form. However, does not produce metamorphosis, is a direct development. Some examples are the lice and the mites.
In insects, metamorphosis is controlled by "ecdysone", a steroid hormone that lacks juvenile hormones and plays a key role in maintaining the larval characteristics of the animal's body. However, there is a a growing problem: several insecticides have characteristics similar to these juvenile hormones, in a way that they end up preventing the individual's metamorphosis by completely inhibiting them.
Amphibian metamorphosis
"The metamorphosis of amphibians is the result of the action of thyroid hormone. (Gudernatsch, 1912) Experience demonstrates that a thyroid transplant or thyroid treatment causes metamorphosis."
In the metamorphosis of amphibians, we observe some resemblance to insects, as they also go through a larval stage (tadpole) and a pupal stage (tadpole with limbs) before giving birth to the imago, which would be the adult stage. O example most common is the frog.
After the "prometamorphosis" phase, when the animals' toes become visible, an interdigital membrane called the palm connects them to form the paddle-shaped swimming paw. Then the hormone called the "pituitary" passes through the bloodstream to the thyroid. At that time, it stimulates the production of the hormone T4, which causes complete metamorphosis.
Next, we will show how the phases of metamorphosis are produced according to each of the types.
Phases of simple metamorphosis
In order for you to better understand simple or incomplete metamorphosis, we will show you the example of the locust metamorphosis. It is born from a fertile egg and starts to develop progressively, without going through a chrysalis phase. During the early stages it does not have wings, as it will appear later as it evolves. Also, it is not sexually mature until it reaches its adult stage.
Stages of complete metamorphosis in insects
To explain complete or complicated metamorphosis, we choose the butterfly metamorphosis. It starts, as in the previous case, from a fertile egg, which hatches in a caterpillar. This individual will feed and develop until the hormones begin to cause the phase change. The caterpillar will begin to wrap itself with a thread that it secretes, until it forms a chrysalis that completely covers it.
During this period of apparent inactivity, the caterpillar will begin to reabsorb its juvenile organs and transform its body completely, until it develops legs and wings. It can last for days or weeks. Finally, the pupa will open, giving way to an adult moth.
Stages of metamorphosis in amphibians
To explain the stages of metamorphosis in amphibians, we chose the frog metamorphosis. Frog eggs are fertilized in water while they are surrounded by a gelatinous mass that protects them. They will develop until the larvae are fully formed and then the tadpole is born, which has a head and tail. As the tadpole feeds and evolves, it will begin to develop legs and, over time, the figure of an adult frog. Finally, when it loses its tail, it will be considered an adult and sexually mature frog.
Which animals have metamorphosis?
Finally, we show a partial list of zoological groups from animals that undergo metamorphosis in its development:
- lissamphibians
- Anurans
- Apos
- Urodels
- arthropods
- Insects
- Crustaceans
- echinoderms
- Molluscs (except cephalopods)
- agnathes
- Salmoniform fish
- Anguilliformes Fish
- Pleuronectiform fish
If you want to read more articles similar to Animals that go through metamorphosis, we recommend that you enter our Curiosities section of the animal world.