Dead beach washed specimen showing smooth carapace when 'hat' has been removed.
Date approximate only(definitely mid to late autumn, and I am 99 %sure re year but if not 1991 then 1990).Scuba dive under jetty. Depth about 4m. Crab was on a lower flatter part of same very large composite red sponge in a spot that prevented decent imaging so I moved it gently onto taller more open part of same sponge. Then returned it to where found.(This jetty is 'sponge central station' WRT diveable SA jetties)
Recently deceased - chromatophores still pulsating.
There have been numerous - perhaps hundreds - of juvenile Cuttle-bones washed-up following the recent stormy weather.
@danimations - do you want this one for the study ... it's in the fridge?
The skin had dried to an interesting shade of burgundy.
Re ID, I read everything I could find online (mainly by @danimations) and came to the conclusion that apama was the only option ... I'm sure Dan will correct me if that's wrong.
Night dive
It was tiny, only about 2-3 cm long and swam head first in "leaps" at a time