Containing marine animals, the species in the Echinodermata phylum contain an herbal system to respire. Depending on their environment determines the various respiratory system.
Asteroidea
Asteroidea or also known as starfish have a very unique respiratory system. Star fish have neither gils nor longs. Their respiration occurs over their surface.The Fold of skin on their dorsal surface permit gas exchange. They have dots on their body surface called papillae. They also use their tube feet on their ventral surface. Water goes into them through the dots and tube feet. Then, they use their hemal system to transport the oxygen throughout their body. The hemal system is a series of sinuses and vessel that go all throughout the starfishes body. The also use their vascular system for gas exchange because it is water-based.
Parastichopus californicus
Parastichopus californicus or also known as the sea cucumber extract oxygen from the ocean water in a pair of respiratory trees that branch off the cloaca just inside of the anus. They breathe through taking water in through the anus and letting it out which is very unique. The trees have a series of narrow tubules branching off. Gas exchange occurs across the thin walls of the tubules, to and from the fluid of the main body cavity.
Ophiothrix fragilis
Ophiothrix fragilis or also known as the brittle star has a respiratory system very similiar to the star fish. Gas exchange occurs through cilia-lined sacs called bursae. Each bursae opens between the arm bases on the underside of the disk. There are 10 bursae. Water flows through the bursae by means of cillia or muscular contraction. The oxygen is then spread throughout the body through the hemal system which is a series of sinuses and vessels distinct from the water vascular system. It is the same system used in the respiration of asteroidea or also known as the star fish.