Do Ants Have Bones?
Ants don’t have bones or endoskeletons (internal skeletons). Instead, they have exoskeletons (external skeletons) which provide structural support and shape to their bodies.
In this article we’ll discuss the ant skeletal system as we discuss why they don’t have bones, what exoskeletons are and what they do.
What Are Bones Anyway?
Bones are rigid body tissues consisting of cells embedded in a hard intercellular material. Its functions include structural support for mechanical action of soft tissues and the protection of such tissues and soft organs.
Bones are only found in the skeletal system of vertebrates.
Why Don’t Ants Have Bones?
Ants are invertebrates, a category of animals that don’t have backbones or bony structures but may either have hydrostatic skeletons or exoskeletons instead.
The former is a type of skeletal system characterized by a fluid-filled compartment within the body called the coelom. It’s typically found in soft-bodied animals such as Cnidarians, earthworms, and sea anemones. The latter on the other hand, is a skeletal system which features an external skeleton called the exoskeleton and is commonly found in arthropods like ants.
What Is An Exoskeleton?
An exoskeleton is a hard, rigid external encasement found in the exterior of many arthropods like ants. Similar to bones or an endoskeleton, they support and protect the soft tissues and organs of the body. Furthermore, exoskeletons have waterproof properties and help protect ants from desiccation or drying out.
In ants and other arthropods, the exoskeleton mainly consists of a coating called the cuticle. This cuticle is formed of both living and non-living layers. The living layer consists of epithelial cells that rest on a basement membrane. These cells are what secrete the non-living material of the cuticle.
At the outermost part of the cuticle is a thin, waxy layer called the epicuticle. This epicuticle is subsequently composed of 3 layers which allow it to reduce water loss and block the invasion of foreign matter.
The innermost layer is called the cuticulin layer, which is made from lipoproteins. On top of this cuticulin layer, is an oriented monolayer of wax molecules which serve as the barrier to movement of water into or out of the body. This fragile waxy layer is then followed by the cement layer which protects it from abrasion.
The inner layer of the cuticle is called the procuticle. This procuticle lies immediately above the epidermis and is primarily made from chitin, a fibrous material consisting of modified polysaccharides similar to the cellulose found in the cell wall of plants. Similar to the epicuticle, the procuticle is composed of 2 layers, the hard outer exocuticle and a flexible inner endocuticle. In general, the procuticle is what provides the exoskeleton the necessary hardness and rigidity.
Advantages Of Exoskeletons
The primary advantage of having an exoskeleton is the protection that it provides. They’re basically body armor which can deform and absorb physical blows to protect the ant’s internal structures. Furthermore, due to the epicuticle, it also helps protect the ant from desiccation and invasion of foreign bodies.
Disadvantages Of Exoskeletons
As exoskeletons are rigid, they can’t stretch to accommodate growth. Because of this, ants have to molt or shed their exoskeletons during some stages in their life cycle to grow and develop. When they do, they become extremely vulnerable to predators due to lack of mobility during the process and the lack of protection immediately after while the new exoskeletons still have to harden.
Apart from that, chemical imbalances and other factors may cause malfunctions in the molting process. Depending on severity, these may cause mutilation and sometimes even result in death.
One other disadvantage is the fact that exoskeletons limit size. This prevents ants from developing more complex structures which may provide them with adaptive advantages and allow them to have a wider size range of prey. That said, there are some advantages that come with being smaller as well, seeing as small creatures tend to survive large calamities. So, it’s actually more of a double-edge sword.
Related Questions
Do Ants Have Spines?
No, ants don’t have spines. Again, ants are invertebrates, a category of animals that don’t have spines or any other bones.
Do Ants Have Teeth?
Ants have external teeth attached to their mandibles, a pair of adapted appendages near the ant’s mouth. These teeth are strong, sharp, and can be used to transport food items, to process food, defend themselves, and even to decapitate or dismember prey.
Summary
Ants like other arthropods are invertebrates, meaning they have no bones at all. Instead, ants specifically, have exoskeletons, hard, rigid external skeletons primarily composed of chitin that support and protect their bodies.
