👉 Spongiactinids are a group of arthropods that include spiders, scorpions, and other insects with a spongy exoskeleton. They have a highly specialized body structure, resembling jellyfish, which allows them to change their shape through the use of an internal sponge-like structure called a spongie. This sponge-like material is capable of varying in size and shape, allowing for adaptations to various environments, such as aquatic or terrestrial habitats.