The hydrostatic skeleton of earthworms is segmented. The coelomic fluid in each segment is largely isolated from the fluid in neighbouring segments by muscle septae, allowing segments to function as independent hydraulic units.
*Question*: Does the coelom act as a hydrostatic skeleton?
*Answer*: Body Cavities Arthropods are coelomate animals, although the coelom no longer functions as a hydrostatic skeleton, as it does in the less-evolved annelid worms.
Instead, it persists as a cavity that typically just surrounds the reproductive and/or excretory organs.