31-year-old Peter has been at the Warriors since 2009 and has made 116 appearances for the Guinness PRO12 side.
He made his Scotland debut in 2013 and has gone on to win three caps for his country.
Junior Bulumakau joined Glasgow in the summer of 2015 and the Fiji-born winger has gone on to make eight appearances for the club and has scored three tries, including a crucial score in the win over Edinburgh Rugby at BT Murrayfield earlier this season.
Fraser Lyle has made eight appearances for the Warriors since joining in 2014. The centre is part of the Scotland 7s squad.
Second-row Tjiuee has made five appearances for the Warriors, but spent several months on the sidelines with a shoulder injury earlier in the season. Scrum-half Nemia has made three appearances, while stand-off Hagen represented the club once.
Glasgow Warriors head coach Gregor Townsend said: "We'd like to wish all our leavers the very best in the next stage of their careers.
"They've all made a tremendous contribution to the club and I'm sure our supporters will show their gratitude after our game against Edinburgh on Saturday."
Retiring at the end of the season: Sean Lamont (112)