• What is metamorphosis?
• The metamorphosis of the butterfly
• The metamorphosis of the frog
• The metamorphosis of the bee
• The metamorphosis of the dragonfly
• "The Metamorphosis" by Franz Kafka

We explain what metamorphosis is and how it occurs in butterflies, frogs, bees and dragonflies. Also, "The metamorphosis" by Kafka.

Metamorphosis occurs at a specific time and under certain conditions.

What is metamorphosis?

In biology, metamorphosis is the process of changes structural and physiological through which certain animals reach adulthood, leaving behind the characteristics obtained from birth. It is a natural process, common to many species of insects, mollusks, amphibians, crustaceans, cnidarians, echinoderms and tunicates.

The changes that this biological process implies can be more or less radical, depending on the type of metamorphosis:

• Complex or complete metamorphosis (holometabolism). It occurs when the characteristics of the initial stages of the animal, say, of the larva or of its primary stages, are radically different from those of adult life. That is, when the animal completely and significantly changes its ways of life, his anatomy and even his habitat of existence, after going through a stage of inactivity and profound transformation.
• Simple or incomplete metamorphosis (hemimetabolism). It occurs, on the contrary, when the changes that the young form of the animal undergoes are not so radical, since its larval or young stage is not so different from its adult stage. Generally, these stages are distinguished only in size, and the animal goes through different "molts" or partial changes, until reaching adulthood.

Both types of metamorphosis are controlled by a diverse set of hormones that induce various reactions and biochemical changes in the organism. This process, in addition, is usually related to the climatic and biological cycles of the nature, so that they always occur at a certain time and under certain conditions.

Metamorphosis has captivated the attention of human beings since ancient times, leading them to explain it through the most diverse theories, and also becoming a metaphor for change, growth and their own life cycle, especially the one that involves animals such as bees waves butterflies, very present in the culture human since its inception.

The metamorphosis of the butterfly

The butterfly usually places its chrysalis under a branch.

The metamorphosis of butterflies is probably one of the best known and studied by humans, and in total it includes the following stages:

• The egg. The initial stage in the life of a butterfly occurs when an egg is laid in the environment (on a branch or a leaf, or wherever depending on the species) and then fertilized. Generally this occurs in strategic places, using viscous substances, and there are usually several eggs deposited. Each one matures, as the life inside it reaches the necessary point, and finally hatches, releasing a larva, which we commonly know as a caterpillar.
• The Caterpillar. Butterfly larvae, called caterpillars, are very popular in gardens, and are elongated animals like a worm, endowed with numerous legs and a robust spherical head, with powerful jaws capable of crushing leaves, stems and other plant fibers from which the caterpillar feeds. Caterpillars can have antennae, protrusions, very different colors and characteristic of the species, and many are even poisonous, but they all have their great objective in common: to eat. They feed frantically until they accumulate in their bodies the size and the Energy just to start the process of metamorphosis. So they look for the right place, usually hanging upside down from a branch, and weave a cocoon out of silks or other fibers that they themselves produce. There they lock themselves up to become adults.
• The chrysalis. Once inside the cocoon woven by themselves, the caterpillars become chrysalis or pupae, and lead an immobile life that lasts about three weeks. During that time, the caterpillar's tissues are modified, dissolved, and built into the shape of a full adult (imago). As this happens, the chrysalis also hardens, until, when the time comes, and thanks to the pressure that the animal exerts from the inside, it cracks, to release an adult butterfly.
• The adult butterfly. After breaking the chrysalis, the butterfly unfolds its newly hatched wings and allows them to dry and fill with hemolymph. Meanwhile, he fully emerges and, still dangling in place, prepares for flight. It is already a individual adult, ready to lead an aerial life, feeding on flower nectar and other similar fluids, and to reproduce and start the cycle again.

The metamorphosis of the frog

In their larval stage, frogs are called tadpoles and they live 100% aquatic.

Another well-known case is that of most batrachians, frogs and toads. These amphibian life animals are the evolutionary step between aquatic and terrestrial life, and for that reason they must always reproduce in water. Its life cycle includes the following stages:

• The eggs. The life of the frog begins when a female deposits her eggs in a body of water, such as a river, a lake or a puddle of some kind, with a male who immediately proceeds to fertilize them. The eggs then mature, as the life inside them reaches the right point, and they hatch to release tadpoles.
• Tadpoles. This is the name given to the frog “larvae”, that is, to their infantile forms, which lead a 100% aquatic life. In fact, they have long, limbless bodies, similar to fish, endowed with tails, gills and a sucker to hold onto objects. Tadpoles live for about three months, feeding on everything possible, during which time they change gradually, as they accumulate the energy necessary for metamorphosis. Then, the changes begin: the hind legs begin to sprout, then the front ones, and the body to increase considerably in size. The lungs develop within the young frog, as the tail and gills are gradually reabsorbed, preparing the animal for its future terrestrial life.
• The adult frog. After metamorphosis is complete, an adult frog leaves the Water and it begins adult life in the dry, although returning from time to time to hydrate and to spawn, thus repeating its life cycle.

The metamorphosis of the bee

The bee undergoes metamorphosis within a hive cell.

Despite living an organized life in their respective hives, the metamorphosis of honey bees is well known to biology. And it includes the following life cycle:

• The eggs. Bee eggs are always deposited by the queen bee, the only one capable of reproducing, inside special cells of the hive, destined to house the young, instead of the honey. The eggs are white and flat, oval in shape, and hatch after about three days.
• Larvae. Fresh out of the egg, the larvae rest in the shape of a "C" in their respective cells, waiting for the worker bees to bring them their food: a kind of honey-based jelly, made by themselves. The larvae are white, elongated and segmented in body, but without limbs and totally blind. They will be fed in this way until they reach the size necessary to become pupae or chrysalis.
• The chrysalis. When they are ready for metamorphosis, the larvae generate a characteristic odor that the workers recognize, and they proceed to seal each cell with wax, isolating the larvae from the outside. In there, hidden from the light, the larva begins a period of inactivity and changes that varies according to the final role that the individual will have in the hive: workers, drones or queens.
• Adult bees. Once the adult or imago stage is reached, bees emerge from their cells to join the complex social life that characterizes these insects.

The metamorphosis of the dragonfly

The adult dragonfly comes out of the water and loses its outer shell.

The dragonfly, popularly known as the "devil's horse" or "serpent", is another insect that undergoes metamorphosis into insects is that of the dragonfly. An individual of this species can live for more than one year, during which time it will have completed the next cycle of life and changes, spending the least amount of that year for adulthood.

• The eggs. Like the rest of the insects, the dragonfly is born from an egg, deposited by a fertilized female, since the dragonflies mate in the middle of the flight. The eggs are generally deposited in plants aquatic, or released into the water of rivers, lakes or ponds.
• The nymph. The larval stage of the dragonfly is also known as a nymph, and begins when an egg hatches and releases a creature of underwater life, humpback, whose feeding is constant and relies on smaller creatures. This life stage can be quite long, since the metamorphosis does not begin until the climatic conditions are suitable for the nymph to emerge from the water. But in the meantime, the nymph will undergo a series of molts and transformations, which will strip it of its hump and provide it with small nymphal wings, as well as the trachea apparatus necessary to replace the gills.
• The adult dragonfly. When ready to emerge from the water, the nymph will search for some aquatic plant to hold onto and begin its ascent to the surface, during which it will lose its outer shell (called exuvia) and sprout from itself as an adult. Since then, it will have a flying life, although restricted to a few months: enough to reproduce and restart the cycle.

"The Metamorphosis" by Franz Kafka

Metamorphosis (Die Verwandlung in German), sometimes published as The transformation, is a story written by the Czech author Franz Kafka (1883-1924) published in 1915. It is probably the best known of all his work.

It is the story of Gregorio Samsa, a 23-year-old traveling salesman, who one day wakes up in his bed turned into a gigantic beetle. This makes it impossible for him to carry out his work, on which his entire family depended.

Finally, unable to communicate with his family and mistakenly injured by his father, who once believed that the insect was abiding by his own mother, Gregorio Samsa dies from an infected wound on his side. His body is found by the saleswoman, who throws it away, and the family continues its existence, a little relieved deep down.

Metamorphosis It has elicited numerous interpretations, some autobiographical, but it is considered one of the most outstanding works of 20th century German literature. Especially since it was written by a bohemian Jew almost two decades before the tragic events of the WWII, in which the Jewish population of Europe was enslaved and annihilated, treating them as if they were less than human beings.