Why is it that everywhere I look Octopus vulgaris is shown to measure 10' (3m) across?

Below is an example of a seemingly reputable site:
http://www.enature.com/fieldguides/detail.asp?shapeID=1074&curGroupID=8&lgfromWhere=&curPageNum=6

I have found scores of examples like these... Is there another "common" octopus besides O. vulgaris?

Or did one get it wrong and everyone is misquoting?

That seems a little large- Octopus vulgaris as found in the Mediterranean Sea has arms about a meter long, so arm to arm would be over 6 feet. The Caribbean Common Octopus is smaller, with arms up to 80 cm, so the arm spread would be about 5 feet. I wonder where the 10 feet comes from? (I'm getting my info from Mark Norman's Cephalopods: A World Guide.

Nancy

I thought O.Vulgaris only got 3 feet across, not per arm. Which is right for the species from the Gulf of Mexico?

10 feet is massive! Where has it been saying that?

The biggest ones i've kept have been from Spain and been just under 3 feet in diameter.

They are definatly my favourite octos too!

I've heard a lot of good things about the O.vulgaris personality but we've had only a few people keep them and report to us on their behavior. What do you like about them, Andy?

Nancy

Ya, iv seen Vulgaris being listed as 10' in many sources saying it's their maximum size. I don't have a clue why or were the 10' comes from either, but from whats been seen...Vulgaris only reaches 3 feet arm-length with a span of 6 feet when spread out.

If anything grows to 10 ft. it's definately the Giant pacific octopus which can surpass that size.

Just the behaviour of them really and their colour. Gorgeous colouration!

I've also had a group of them in a 2800 litre tank before and there was a hierachy in the group (of around 6 at any one time). Pretty easy to train as well, I used to do loads of enrichment with them and they all responded well to it all.

Cant wait to get myself an octo tank at home!!

There is a lot of variation in size at maturity between octopuses of the same species in the same location and even more between locations. Cephalopods just don't fit into nice little standardized bins like fish do. To further complicate matters, length, and most especially arm length, is a really poor measurement of size in a stretchy animal which has no bones. ML is much better, weight is best.

These guys can be cannibalistic Andy. Yup, easy to train, smart and strong. Prone to escapes. Most of my octopus research in Bermuda is on these guys.

So are they like a burmese python...power feed the heck out of 'em? (As long has I have the room and the filtration) and get a good size in no time?