Doumanis, also a forward, only managed two senior games following a three-year stint in the WAFL playing for Claremont.
List manager, Naomi Maidment, thanked Perry and Doumanis for their contributions.
“These are never easy decisions to make, especially as Britt and Tessa are great people and talented footballers,” Maidment told club media.
“We are grateful to have had them at Port Adelaide and they will always hold a special place at the club as members of our inaugural list.
“We wish them all the best for the next chapter.”
The list calls come after the Power signed Adelaide star Ash Woodland in the priority signing period (PSP).
Woodland was instrumental in securing Adelaide's Season Six premiership, subsequently claiming the league's leading goalkicker and being named an All-Australian for the first time.
"Ash is a dominant forward and joins us from a successful, well-established program, so we know her experiences and skills will add huge value to our footy club," Maidment said.
Players must have been on an AFLW list for at least three seasons to be eligible for the PSP, which ends on March 8.