Metamorphosis is a process in which animals undergo extreme, rapid physical changes that occur within a particular time after birth. The result of metamorphosis may be a change to the organism’s entire bodily makeup, such as a change in the animal’s number of legs, its means of eating, or its means of breathing. Metamorphosis is also required for sexual maturity, as pre-metamorphic members of specific species are typically unable to mate or reproduce.
This process is undergone by most insects. Animals that undergo metamorphosis include fish, mollusks, and many other types of sea creatures which are related to insects, mollusks, or fish.
Metamorphosis is a miraculous process. The speed and extent of cell growth and differentiation is astonishing. The process of metamorphosis involves a re-activating of genes that allow animal cells to change from one cell type to another, and is triggered by hormones, which the animal’s body releases as conditions for metamorphosis approach. These hormones cause drastic changes to the functioning of cells, and even behavioral changes such as the caterpillar becoming a chrysalis.
Type of changes
There is two types of metamorphosis — complete and incomplete. In complete metamorphosis, a larva completely changes its body plan to become an adult. The most well-known example is that of the butterfly, which starts out as a worm-like, leaf-eating caterpillar and transforms into a flying, nectar-drinking creature with an exoskeleton. Other animals which transform from a worm-like larval stage into an animal that looks completely different include beetles, flies, moths, ants, and bees.
With incomplete metamorphosis, only some parts of the animal’s body change during metamorphosis. Animals that only partially change their bodies as they mature are called “hemimetabolous,” meaning “half-changing.” Cockroaches, grasshoppers, and dragonflies, all hatch from eggs looking a lot like their adult selves. They do acquire wings and functioning reproductive organs as they grow, but they do not completely remake their bodies like their completely metamorphosing cousins do.
Metamorphosis can be hidden from the view of most people. Many of us may have only witnessed the process of metamorphosis by raising caterpillars into butterflies. The idea of a worm-like caterpillar wrapping itself in a chrysalis for close to 2 weeks, then emerging as a beautiful butterfly is certainly a magical experience. But the obvious changes of appearance, such as the growth of wings, don’t do justice to just how miraculous this process is. In the chrysalis, such as with the Monarch, caterpillars don’t simply gain legs, wings, and an exoskeleton. They also grow new eyes, lose their leaf-eating mouth parts and replace them with nectar-sucking proboscises, and gain mature reproductive organs. To accomplish this drastic change, a caterpillar basically digests itself. A great deal of energy and raw materials are required to turn a caterpillar into a butterfly.
To make it possible, caterpillars release enzymes that dissolve most of their bodies! Indeed, the hard shell of the cocoon is required not just to protect the metamorphosing insect from attack: it is required to keep its liquefying body bound together. Not all of the caterpillar’s cells are dissolved by these enzymes. Special tissues called imaginal discs survive – and they use the soup that used to be the rest of the caterpillar’s body for nutrition. By consuming the proteins, vitamins, and minerals – everything you need to build a butterfly – these imaginal discs are able to grow incredibly quickly, developing into the butterfly’s mature body parts.
The new body has almost nothing in common with the old body. It has new legs, new sensory organs, a new exoskeleton, a new reproductive system. Even its digestive system does not work the same way, since it must now digest nectar instead of leaves, in addition to the beautiful wings.
As Lepidopterists, it is our hope to open a door into the miracle of metamorphosis. Starting today, my business Sky Lyfe (LYFE stands for Liberating Yearly From Extinction) will have an outdoor Monarch chrysalis exhibit available for view at the Adirondack Wildlife Refuge in Wilmington. These two open exhibits will be located in the outdoor educational presentation area, placed on the outer section of the pollinator garden. The educational presentation area was designed and built by Sky Lyfe with all recycled material to bring awareness to pollinators. If you have never seen a butterfly emerge from a chrysalis, now is your chance to experience the magic.