An exoskeleton is an external covering for the body that can be found in some invertebrate animals. It is most commonly seen with arthropods, giving them support and protection as they go about their daily living activities. Machine-based exoskeletons are also available to provide human-based supports that offer a similar set of benefits.
The exoskeleton contains a rigid and resistant set of components that fill functional roles to protect, sense, and support the creature. It also offers a defensive mechanism against pests or predators, providing an extra layer of help through an attachment framework to the animal’s musculature.
Most exoskeletons contain chitin, calcium, and carbonate to give this structure the remarkable strength it provides. The material is about six times stronger and twice as stiff when compared to the tendons of the vertebrate. It is a function that has experienced independent evolution numerous times, with almost 20 different calcified versions alone. Although they provide several purposes, they can also reduce the movement of the animal.
That’s why biologists look at the advantages and disadvantages of an exoskeleton in the following light.
List of the Advantages of an Exoskeleton
1. An exoskeleton allows for complex movements because of jointed appendages.
An exoskeleton is the thick covering that you can find on the outside of some animals. The design of this defensive layer often comes with flexible joints that work with the creature’s underlying muscles. It is a benefit that allows for a wide range of movements for the animal, and it is ultimately the opposite of how humans are put together with their endoskeleton.
Grasshoppers, scorpions, and shrimp are all examples of animals that contain this feature. Most insects have several segments that make it look like each body part receives coverage from a separate piece of their exoskeleton. This design is what makes it possible for the head and body parts to separately move.
2. It protects an animal against abrasion or physical damage.
An exoskeleton provides an exceptional protective covering for an animal’s muscles and soft internal organs. Creatures that do not have this protection are more vulnerable to injuries that impact their soft tissues. The material of this defensive layer can be made from bone or a combination of other elements so that it always maximizes the potential of this advantage. That means the animal can go almost anywhere within its habitat without worrying about the consequences of that decision.
3. This structure increases the leverage of the animal.
An exoskeleton is typically made up of several layers. You will have a hard outer surface and a flexible inner layer working together to provide a significant amount of protection against predators. There’s a waxy surface on the innermost layer that protects the animal against dehydration. Most arthropods have a secondary layer that prevents this first one from getting torn or damaged.
This structure gives the animal a lot of leverage in a variety of ways. It can control its habitat, use the outer layer as a shield or weapon, or even have it as a tool that can make life more comfortable in a variety of ways.
4. Exoskeletons prevent dehydration or getting too wet.
The hard covering on the outside of this structure helps to support the body of the animal in a manner that is similar to wearing a portable raincoat. It will prevent the creature from drying out with its flexible inner layers while stopping the animal from getting too wet to function. That means there is a natural layer of defense against long spells of heat or cold. It is easier to maintain the overall perspective of health because of this protective shield. That’s why it is such an excellent survival strategy.
5. The frequency of molting is under hormonal control.
The stages that occur between molts for arthropods are referred to as instars. This time is when the actual tissue growth occurs for the creature, although it won’t expand in size until after the next molt occurs. Ecdysone controls this process, and it is the hormonal control that dictates the frequency of a new defensive layer forming.
Once the cuticle of the exoskeleton weakens through the enzymatic processes, the animal crawls out. Then it will suck in water or air to inflate the new exoskeleton so that the hardening process starts.
6. It removes the need for a hydrostatic skeleton.
Body plans can diversify within the structures of an exoskeleton, which means that the evolutionary processes can expand because of this support structure. That makes it easier for the animals to adapt to their changing environments as time passes, which is why this structure is the most successful one currently known to biologists. Many of the earliest animals that we know of on our planet used it, and this approach is still widely used by nature today.
Although chitin exoskeletons are quite heavy and place a constraint on the size of the animal, there is better leverage for moving limb muscles when compared to the processes used by an endoskeleton.
7. Exoskeletons promote a high level of diversity.
Arthropods are the most diverse group of organisms when researchers look at most ecosystems. Studies that looked at Canadian biodiversity specifically found that as early as 1994, there were up to 8,0900 different species in a single peatland habitat common to the country’s boreal forests. Because the outer skeleton provides more room for internal development and evolution, there is a strong likelihood that there are thousands of additional species out there in the world that we know nothing about yet.
Arthropods cover several size classes, exist in several environments, and have dispersal abilities. They work to maintain soil structures and fertility while regulating the populations of other organisms. It could be argued that these creatures are the most essential component of the global ecosystem.
List of the Disadvantages of an Exoskeleton
1. Exoskeletons don’t stretch or expand.
An exoskeleton is unable to take the same amount of shock that a soft tissue outer layer can withstand. Animals that are close to their molting time can face life-threatening consequences if an impact is severe enough. If a crack or injury does occur, then the healing process is a lot slower with this natural structure. If a fissure develops, then it may never heal at all.
This problem can end up causing a clot that threatens the life of the animal. The only way to thoroughly heal after this outer structure gets damaged is to replace it entirely through the molting process.
2. Special modifications are necessary for sensory pickup.
The thick outer layer of the exoskeleton makes it challenging for the animal to have sensory perception if their surrounding environment. It creates a structure that’s too hard to feel anything except pressure or significant impacts. This problem can put the creature into dangerous situations at times without their knowledge because the dangerous circumstances are above their protective features.
3. It can sometimes interfere with breathing without accommodations.
If an animal is approaching the time it is supposed to molt, then the pressure that their body places on the exoskeleton can interfere with their breathing. This disadvantage is also present when there are significant moisture levels in the creature’s habitat. Unless the natural processes get started to rectify the situation, there could be health concerns with this problem that are problematic enough to put its life in danger.
4. An exoskeleton provides a significant restriction on growth.
An exoskeleton is a substantial body component that would be unmanageable if an animal were to grow too large. That’s why the majority of the creatures that have this protective feature are typically small. It would be almost impossible for any movement to occur for a larger animal with an equitable protective layer. Most of the examples in nature are of insects or beetles because they don’t experience the size restrictions that a bear or a Tiger would have in the same circumstances.
5. Animals must shed the item at regular intervals if it doesn’t grow with them.
Unless the exoskeleton of the animal grows with it, molting is a significant disadvantage of this natural feature. Arthropods become highly vulnerable to predators during this time of growth because the new surface starts out soft and requires an extensive amount of time to harden. Until there is a complete restoration of the outer protective layer, the animal has almost no protection at all.
The molting process is so dangerous for some animals that it must remain in a safe and static environment to prevent life-changing threats from impacting it. Bacteria, mites, or fungal spores can easily penetrate an animal going through the moiling process.
6. Molting an exoskeleton means the animal cannot eat.
Tarantulas encounter unique challenges during the molting process. If the animal tries to eat before the exoskeleton completes its hardening, then the fangs and claws can get bent out of shape. It would leave the creature in a state where it wouldn’t be able to eat at all. Bone-based exoskeletons don’t encounter this issue except at birth, although the calcified nature of the structure can break like an arm or a leg.
Pros and Cons of Mechanical Exoskeletons to Consider
Mother Nature might be the designer of the world’s first exoskeletons, but humanity is following close behind in her footsteps. More factories, distribution centers, and warehouse operations are adding this technology to their services. Companies and workers use these devices to increase safety without compromising internal productivity levels.
Exoskeletons are wearable devices that a person places on their body to reinforce, augment, or restore performance. This technology can be made from plastic parts, carbon fiber, or various metals. It works to prevent musculoskeletal disorders in workers that could cost an organization millions of dollars annually. Employees that get to use this technology complain of less shoulder and back pain while still being more physically active than without it.
Exoskeletons have the option to transfer the weight of a user’s arms from the shoulders and upper body to that person’s core. This action reduces the amount of physical stress that gets placed on the body during cumbersome lifting processes. Although humans carry some of the weight of the objects being transferred when using this technology, it can increase individual durability and improve movement.
The fossil record only contains mineralized exoskeletons. Since these are more durable than the type found on arthropods, this evidence makes sense. That fact makes it challenging to look at the history and evolution of nature’s approach to this protective mechanism, although we do know that just before the Cambrian Period, there were phosphate, calcite, aragonite, and silica examples in nature.
Exoskeletons provide animals with a critical amount of protection so that they aren’t immediately vulnerable to predators. Although it presents particular challenges to the creature during their molting stage, it is something that’s easily managed in most circumstances.
As we look at all of the advantages and disadvantages of an exoskeleton, it is easy to see what it’s such an active evolutionary component. It stops predators, leverages muscle movements, and offers several additional benefits that often outweigh the issues involved.
Brandon Miller has a B.A. from the University of Texas at Austin. He is a seasoned writer who has written over one hundred articles, which have been read by over 500,000 people. If you have any comments or concerns about this blog post, then please contact the Green Garage team here.