
TQ!!
What kind of octo do you have, and how old?
Octo are infact known to be cannibals.
The male has a modified arm, called a Hectocotylus, it is generally the third right arm. They use this to transfer sperm to the female.
As far as breeding I have never done it so perhaps someone else has had experience. But certain femals of octo can carry sperm until they are ready to fertilize their eggs. Breeding, and carring for their eggs, are usually the last things your octo will do in their life.
GL to you and hopefully someone with breeding experience can chime in!