As Speirs says in his intro to Opuntia, “Whole-numbered Opuntias are sercon, x.1 issues are review zines, x.2 issues are indexes, and x.5 issues are perzines.”
Contributors have included Anna Banana (Banana Rag), Sheryl Birkhead (The National Fantasy Fan), Chester Cuthbert, Teddy Harvia, Andrew Lin, Mark Manning, Dave Panchyk, Robert Runté (Neology), Garth Spencer (The Royal Swiss Navy Gazette, BCSFAzine), and Taral Wayne (Broken Toys, DNQ). Also included were reprints of the article "History of the Canadian Science Fiction Association", by Jack Bowie-Reed.
Letters came from Harry Andruschak, Sheryl Birkhead, Ned Brooks (It Goes On The Shelf), Brian Earl Brown, Ken Cheslin (Les Spinge, Nazgul's Bane), Buck Coulson (Yandro), Chester Cuthbert, Don Fitch, Steve George, Judith Hanna (Fuck The Tories), Karl Johanson (Under The Ozone Hole), Paula Johanson (The Central Ganglion), George Laskowski (Lan's Lantern), Rodney Leighton, Joseph Major (Alexiad), Sam Moskowitz (Different), Theo Nelson, Joseph Nicholas (Fuck The Tories), Lloyd Penney (Torus), Mark Plummer, Robert Runte (Neology, The Monthly Monthly, New Canadian Fandom), Robert Sabella, Leah Zeldes Smith (Stet, Contact!), Alan Stewart (Thyme, Ethel the Aardvark), John Thiel, Alexander Vasilkovsky (Chernobylization), Harry Warner, Jr. (Horizons), Henry Welch (The Knarley Knews), Walt Willis (Hyphen), and Franz Zrilich, among others.
In 2005, Opuntia won the Aurora Award for Best Fanzine Fan Achievement Award from the Canadian Science Fiction and Fantasy Association.
However, Opuntia is not limited to just science fiction, since each issue is different. Dale Speirs is active in the mail art community and some issues are devoted to this topic. Other topics have included rubber stamping. Opuntia also reviews zines and prints a number of letters from readers in most issues.