Sepia apama has a short life span of only 1 – 2 years.  Although not much is known about them outside of breeding season, there is a lot known about their reproduction.  During the austral winter (May through July), hundreds of thousands of them come together, mate and lay eggs in the northern Spencer Gulf (Encyclopedia of Life).  There are two alternate life cycles for them that solely depend on their growth rate.  If they have a rapid juvenile growth, they mature in 7-8 months and then mate as a smaller organism.  If they have a slower juvenile growth, they mature in their second year instead and then mate as a larger organism (Hall et al, 2007).

                                        Source: ABC Natural History Unit

    Mating is very competitive, as the male to female ratio is sometimes as high as 11:1 (Encyclopia of Life, 2013).  Because of this, larger males will fight the smaller ones for which female they mate with.  Smaller males will sometimes even camoflauge themselves to look more like females in order to get closer to them.

Next head over to see how they interact with others!