Arthropods are protected by an outer covering of a hard protein chitin, similar in function to the protein keratin in hair, nails, hooves, beaks, claws, etc., elsewhere in the animal kingdom. Some arthropods particularly marine ones further harden it through biomineralization with calcium compounds.
Because of the rigidity of the arthropod exoskeletons, they need to periodically shed it (moult) in order to grow.
slime
exoskeletons
what is seahorse outer-covering
It is called an exoskeleton. That means it is a thick durable outer shell somewhat like an ant's.
Mosquito have a hard outer shell, similar to many other species of insects. This shell protecting and armoring their bodies is known as an "exoskeleton." Exo is the prefix regarding exterior or outside.
The outer covering of the eyeball is cornea.
Amphibians do not have outer covering.
Bat is a mammal, so it's outer covering is hair whereas bird's outer covering is feather.
A seals outer covering is thick skin.
an ant's outer covering is their exoskeleton
Camels have hair as their outer covering.
Tonoplast is the outer covering of vacuole