Exoskeleton
An exoskeleton is a hard external shell that surrounds the body and offers support and defense.
It is primarily found in arthropods like insects, crustaceans, and arachnids as well as some mollusks. It is made of chitin, a hard, protective polysaccharide.
Characteristics of Exoskeleton:
- Made of chitin.
- External hard covering.
- Limits growth and mobility.
- Offers support and protection for the body.
- To allow for growth, it must molt or shed.
Advantages of Exoskeleton:
- Excellent defense against predators and environmental dangers.
- Can support heavy loads compared to the size of the animal.
- Maintains structural integrity even under high physical stress.
- Offers waterproofing and desiccation resistance.
Disadvantages of Exoskeleton:
- Restrictions on growth and mobility because the animal must shed its old exoskeleton in order to grow.
- Can be heavy or bulky depending upon the creature’s size.
- Limits gas exchange and calls for specialized respiratory structures.
- Vulnerable to harm and deformation if the animal experiences extreme physical stress.
Difference Between Endoskeleton And Exoskeleton
Exoskeletons and endoskeletons are two different categories of support systems that can be found in the animal kingdom. An exoskeleton is an external hard covering that encases the body and serves as support and protection, whereas an endoskeleton is an internal framework made of bones or cartilage that offers support, protection, and anchorage for muscles. Invertebrates like echinoderms (like starfish) and cephalopods as well as vertebrates like humans have endoskeletons (e.g., squid).
The majority of arthropods, such as insects, crustaceans, and arachnids, as well as some mollusks, like snails and clams, on the other hand, have exoskeletons.
Exoskeletons and endoskeletons both serve as structural supports, but they are distinct in terms of their location, make-up, and developmental origins.
Understanding these variations can help us better understand the special adaptations and skills that these various skeletal system types in animals have developed over time.