In tunicates, the anus empties into the excurrent siphon. what is the advantage of this anatomical arrangement?

TUNICATES are hermphrodite, with their general excurrent pore. They can release sperm and eggs through this structure. These organisms are considered filter feeder eating mianly plankton. Adults, are sessile and form a leathery tunic hence the name. This tunic supports and protects the animal. They have 2 openigs in the body the oral siphone and atrial siphone, Oral siphon sucks water into the animal and the atrial siphon squirts out the water from the animal's body.