Body Fluids Help Molt, Extend Wings

Biological Strategy

Dragonflies and damselflies

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Image: USDA Forest Service, Coconino National Forest / CC BY SA - Creative Commons Attribution + ShareAlike

Distribute Liquids

Liquids include water, as well as body fluids such as blood, gastric juices, nutrient-laden liquids, and more. To survive, many living systems must move such liquids within themselves or between locations. Because of their properties, liquids tend to disperse unless they are confined in some way. To address this, living systems have strategies to confine fluids for transport, and to overcome barriers such as gravity, friction, and other forces. Some of these same barriers also provide opportunities. Trees and giraffes face the same challenge: how to move fluids (water and blood, respectively) upward against gravity. But their strategies are quite different. The tree moves water using capillary action and evaporation, possibly due to water’s properties of polarity and adhesion. The giraffe’s tight skin provides pressure to assist in blood circulation. and keep blood from pooling in the legs.

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Transform Mechanical Energy

Mechanical energy is made up of kinetic energy (the energy of an object in motion) and potential energy (stored energy). Organisms use mechanical energy in a variety of ways, including capturing prey, transporting seeds, and moving around.

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Insects

Class Insecta (“an insect”): Flies, ants, beetles, cockroaches, fleas, dragonflies

Insects are the most abundant arthropods—they make up 90% of the animals in the phylum. They’re found everywhere on earth except the deep ocean, and scientists estimate there are millions of insects not yet described. Most live on land, but many live in freshwater or saltwater marshes for part of their life cycles. Insects have three distinct body sections: a head, which has specialized mouthparts, a thorax, which has jointed legs, and an abdomen. They have well-developed nervous and sensory systems, and are the only invertebrate that can fly, thanks to their lightweight exoskeletons and small size.

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Nature’s Innovations: Animals as Engineers

This lesson, with eight short videos, examines how animals have solved engineering problems and how humans have mimicked those solutions. This lesson addresses middle and high school Next Generation Science Standards in Life Sciences and Engineering Design

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The body of the dragonfly molts and extends its wings by pumping body fluid.

“In addition, there are a series of special mechanisms that help the dragonfly to shed its skin. The body of the dragonfly shrinks and becomes wrinkled in the old body. In order to ‘open’ this body, a special pump system and a special body fluid are created to be used in this process. These wrinkled body parts of the insect are inflated by pumping body fluid after getting out through the slot. In the meantime, chemical solvents start to break the ties of the new legs with the old ones without damage.”

“The wings are fully developed already but are in a folded position. The body fluid is pumped by firm contractions of the body into the wing tissues.” (Yahya 2002: 25-26)

Dragonfly Metamorphosis

This video from Shape of Life depicts the life cycle of the dragon fly as it leaves its freshwater larval stage for a life in the air. The process of larva molt and extension of the wings is shown from 0:47 - 1:20.

Last Updated October 2, 2018

References

“When overloaded, thin-walled tubes tend to buckle, but the fluid pressure of the hemolymph may resist this failure.” (Wootton 1992:120)

Journal article

Functional Morphology of Insect Wings

Annu Rev Entomol. 37: 113-140 | 01/01/1992 | Wootton RJ

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Reference

“Hemolymph performs a vital skeletal function. During the final molt, hemolymph is pumped into the veins of the crumpled wings and expands them to flight readiness. Once the wings have hardened, the hemolymph drains out again, leaving hollow wing veins that act like airplane struts to strengthen the wings.” (Cooper 2014:26)

Book

Dragonflies: Q&A Guide: Fascinating Facts About Their Life in the Wild

Mechanicsburg (PA): Stackpole Books | 01/09/2014 | Cooper A

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