As he says in the intro, "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 Teddy Harvia, winner of the the Fan Artist HUGO Award. Opuntia has won the 2002 Prix AURORA 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.