Answer:
Invertebrates without Exoskeletons
They use fluid in their bodies to keep their shape and move around. Some invertebrates without skeletons are jellyfish, slugs, and worms. Invertebrates that don't have exoskeletons need other ways to protect themselves. Jellyfish have powerful stingers on their tentacles.
A non-helical hydrostatic skeleton structure is the functional basis of the mammalian penis.[3] Helically reinforced hydrostatic skeleton structure is typical for flexible structures as in soft-bodied animals.
The Coleoidae do not have a true endoskeleton in the evolutionary sense; there, a mollusk exoskeleton evolved into several sorts of internal structure, the "cuttlebone" of cuttlefish being the best-known version. Yet they do have cartilaginous tissue in their body, even if it is not mineralized, especially in the head, where it forms a primitive cranium. The endoskeleton gives shape, support, and protection to the body and provides a means of locomotion.
Explanation: