http://i18.photobucket.com/albums/b137/heyimrich/normal_rudiger-octopus.jpg
Does anyone know what kind of octopus this is?

Looks like bimaculoides, not ruling out bimaculatus without a closer look at the eyespot. Did you get him at Marine Depot?

How big is he, and good photo, btw.

Dan

Hes not mine, I found the pic on this site(forgot whos it was). It looks exactly like the one at my lfs without the blue spot thow. Also the one at my lfs is about the size of a 3 year olds fist.

Nevermind, then. The blue spot is what was diagnostic.

Dan

Besides the telltale ocelli of the ubiquitous bimac (and there are a LOT of ocellated octopuses besides bimacs), there are many other subtle keys to IDing octopuses. Finding a pic on the internet that "looks just like" the octopus you saw is only useful if you know specifically what to look for. To ID an unknown ceph, a scientist will be looking at many subtle keys such as particular colorations and patterns, size of the eyes, size and layout of the suckers, length and girth of arms, how far down the arms the web reaches. If the LFS knows (or can at least guess) where the octopus was collected, it's a very useful piece of information.

I don't have a kid, so I'm fuzzy on how big a 3-year olds fist is. Outside of academic circles, most scientists adhere to the International Food Sizing Scale for describing cephalopods size. It is:

Rice grain
Pea
Grape
Walnut
Ping Pong Ball
Kiwi fruit
Lemon
Orange
Grapefruit
Coconut
Cantelope
Watermelon

And don't give me any flak about a ping pong ball not being food. Ping Pong Balls were featured prominently in one of my favorite Swedish Chef Skits.

Snap a pic of the actual critter and let us take a stab at it!

Cheers, Cephjedi

you forgot to mention giant pumpkins... and who says you cant eat a ping pong ball...