The color of the madreporite is light orange, and it has raised pores that connect to the water vascular system.
12.
Indeed, the blood itself is essentially identical with the coelomic fluid that bathes the organs directly, and also fills the water vascular system.
13.
The water vascular system of the sea star consists of a series of seawater-filled ducts that function in locomotion and feeding and respiration.
14.
Although the contents of the water vascular system are essentially sea water, apart from coelomocytes, the fluid also contains some protein and high levels of potassium salts.
15.
The water vascular system serves to transport oxygen from, and carbon dioxide to, the tube feet and also nutrients from the gut to the muscles involved in locomotion.
16.
A central haemal ring surrounds the pharynx next to the ring canal of the water vascular system, and sends off additional vessels along the radial canals beneath the ambulacral areas.
17.
Although they possess tentacles around the mouth derived from the water vascular system, they have no true tube feet, and are therefore believed to be related to the Apodida.
18.
The coelom, or body cavity is divided into three chambers in the larva, two of which form the water vascular system, while the other remains as the adult body cavity.
19.
All these groups tend to be radially symmetric and have a water vascular system that operates by hydrostatic pressure, enabling them to move around by use of many suckers known as tube feet.
20.
All these groups tend to have radial symmetry and have a water vascular system that operates by hydrostatic pressure, enabling them to move around by use of many suckers known as tube feet.
