Many starfish are comprised of endoskeletons or inner skeletons that are composed of calcium carbonate plates called ossicles, which allow scientists to believe why they might be related to chordates. Sea stars are also comprised of what is called a water vascular system. This system allows many of echinoderms to move, food and waste transportation, and respiration.
Wumbo Skeleton
Water enters the system on the upper surface called the madreporite, which is an opening that acts as a pressure-equalizing valve. This process leads to the movement of the fish as well as the ability to consume sea creatures on the floor. However the strength of the star fish's limbs itself does not come from its skeletal system. Instead it derives from solid spines and plates that are part of their skin, which helps make the bodies rigid. The ossicles in a star fish function in a way that is very similar to our joints and ligaments, for they move along each other forming connections that act as joints, allowing the star fish to move.
Many of us think of this classic cartoon character when we discuss star fish, unfortunately Patrick isn't the discussion here. Although the star fish's skeletal system seems very vast and complicated, its functions are very simple, making these creatures interesting to study, some producing a few laughs as well.