It was Peter Williams, an jamaican born actor who is actually living in Canada. Beside playing Apophis in SG1 he also is famous for his work in TV. He also acted in Lost and Crossing Jordan.
Stargate SG-1 season 8 is his last season in the series where he plays a major role. He will appear though as a guest star in later episodes, spin-offs (Atlantis and Universe) and Stargate movies...
Trying to ascertain if Daniel Jackson is alive and safe on Abidos, Jack O'Neil knowing that Daniel has allergies sends a box of tissues through the Stargate. The reply is an empty box with the writing: THANKS SEND MORE
Israeli Actress Mili Avital. http://www.imdb.com/name/nm0000815/
I don't think she actually has a named character in the episode, but I believe that the actress is Janette Devries (spelt as de Vires in the credits). She played the blonde, female serpent guard. The only other blonde besides Amanda Tapping is Rachel Hayward who plays the the USAF sargeant that gets kidnapped by the Goa'uld when the gate opens.
Kavan Smith played Major Evan Lorne of the Atlantis Expedition.
The airman who was captured by Apophis was Sergeant (unknown grade) Carol Wetterings. She was played by actress Rachel Hayward.
There are a number of instruments that are played in the opening credits of Stargate Universe. It is an orchestral piece.
Tracy Westerholm has: Played Blonde in "MacGyver" in 1985. Played Marshall in "Xtro II: The Second Encounter" in 1990. Played SF in "Stargate SG-1" in 1997. Played SF Guard in "Stargate SG-1" in 1997. Played Female Soldier in "Stargate SG-1" in 1997. Played Airwoman in "Stargate SG-1" in 1997. Played Surveillance SF in "Stargate SG-1" in 1997.
Sheri Rabold has: Played Physiotherapist in "Stargate SG-1" in 1997. Played Scientist in "Stargate: Atlantis" in 2004. Played Lab Assistant in "Stargate: Atlantis" in 2004. Played Molly in "Sanctuary" in 2007. Played Protestor in "Battle in Seattle" in 2007. Played Molly in "Sanctuary" in 2008.
James Chutter has: Played Footman in "Snow White" in 2001. Played Babbis in "Stargate: Atlantis" in 2004. Played Wraith scientist in "Stargate: Atlantis" in 2004. Played Male Wraith in "Stargate: Atlantis" in 2004. Played Medical Examiner Willoughby in "Time Enough at Last" in 2004. Played Bridge Tech Wraith in "Stargate: Atlantis" in 2004. Played Bridge Officer Wraith in "Stargate: Atlantis" in 2004. Played Billy Wraith in "Stargate: Atlantis" in 2004. Played SPC Woodward in "Shower of Bullets" in 2005. Played Security Familiar in "Blade: The Series" in 2006. Played Dog Mime in "Mime Massacre" in 2006. Played Deputy Joe in "AVPR: Aliens vs Predator - Requiem" in 2007. Played The Fly Keeper in "Spiderfly" in 2008.
Gerry Durand has: Played Man on Elevator in "Cloned" in 1997. Played Controller in "The Net" in 1998. Played ND Cop in "Dark Angel" in 2000. Played Captain Levine in "Stargate: Atlantis" in 2004. Played Marine Captain in "Stargate: Atlantis" in 2004. Played Airman in "Stargate: Atlantis" in 2004. Played Sergeant in "Stargate: Atlantis" in 2004. Played Townie in "The Boxing Day Classic" in 2005. Played Country Club Valet in "Diary of a Wimpy Kid: Dog Days" in 2012.
Amanda Tapping
Geoff Redknap has: Played Jup in "Stargate SG-1" in 1997. Played Oranian Lieutenant in "Stargate SG-1" in 1997. Played Old Colonel Sumner in "Stargate: Atlantis" in 2004. Played Undead Cop in "Kingdom Hospital" in 2004. Played Old Sheppard in "Stargate: Atlantis" in 2004. Played Goon in "Glitched" in 2005. Played Worm Host Creature in "Bloodsuckers" in 2005. Performed in "Supernatural" in 2005. Played Mad March in "Alice" in 2009. Played Sidewalk Laptop User in "Protection" in 2010.
Morris Chapdelaine has: Played Tenat in "Stargate SG-1" in 1997. Played Ori Prior in "Stargate SG-1" in 1997. Played Cloaked Phantom in "Ebenezer" in 1998. Played Sallust in "Andromeda" in 2000. Played Alexander Luthor in "Smallville" in 2001. Played Newborn Wraith in "Stargate: Atlantis" in 2004. Played Judge in "The L Word" in 2004. Played Puppeteer in "The Puppet Life" in 2009.
Claudia Black. Also starred in stargate and farscape
Efosa Otuomagie has: Played Jaffa in "Stargate SG-1" in 1997. Played Security Police in "Stargate SG-1" in 1997. Played Instructor in "The Net" in 1998. Played Dr. King in "The Twilight Zone" in 2002. Played Bus Driver in "16 Blocks" in 2006.
Ocean Bloom has: Played Worker with water in "Stargate SG-1" in 1997. Played Female Jaffa in "Stargate SG-1" in 1997. Played Vegas Showgirl in "I Spy" in 2002. Played Body Builder Speed Dater in "Psych" in 2006. Played Gerdie in "Psych" in 2006.