You will find that many (and I suspect yours) octopuses show completely different colors and textures so IDing one based on color/texture is almost impossible. Length of arms vs mantle length, false eye spots below the real eyes, consistent stripes, webbing(or lack of in your case) are all good clues though.
I would venture to say that based upon the arm length that it is NOT a Mercatoris/Jobini (Atlantic dwarf).
Looks like a male in Abdopus (star-like pattern around the eye, slight branching on the papillae above the eye, enlarged suckers on arms II and III). Could be aculeatus, but those enlarged suckers look really big.
If you have University access you should be able to download this paper which describes the body patterns of aculeatus- see if it compares to what you have. (If you can't access it, please let me know)