While we are waiting on photos , how about a few more details. Where did you buy/get it? Do you know its originating body of water? Roughly what is the mantle (body from behind the eyes to the mantle tip) length compared to the arm length in terms of a AL:ML ratio. Size guesses are usually way off. Most people can determine a ratio better than actual lengths (partially because they change as the octos move and partially because we are not very good at sight measuring). What colors did you see during acclimation? Did you see only smooth skin or notice any bumps on the mantle? How many rows of suckers are on the arms (most we see will have 2 rows)?
He came from the centerville aquarium and they said he came from California.His mantle is about an inch or a little less. His arms are about an inch to 2 inches. he mostly seems to be smooth with a few bumps around the eyes. During acclimation he seemed to be light and dark red. I think that is all.
hummm, are the O.briareus and O.mercatoris supposed to come from CA too? I am wondering if "coming from California" is referring to the wholesaler rather than the origination of the animal. 2:1 arm to mantle ratio and red coloring with few bumps could easily describe a merc (and would exclude O.briareus at a 1" mantle size and I believe O.joubini has longer arms) but I have no experience with West Coast species. You can scan the List of our Octopuses for 2008 in the stickies at the top of the Journals and Photos forum and look for O. mercatoris links for some comparison pictures.