• Looking to buy a cephalopod? Check out Tomh's Cephs Forum, and this post in particular shares important info about our policies as it relates to responsible ceph-keeping.

Octopus Colors


Pygmy Octopus
Apr 6, 2003

I have a Bimaculoides that I received May 2, 2003 and was wondering if anyone could tell me how their octopus' mood/behavior effects the color of the octopus. Mine seems to usually be a gray-brown color but sometimes he turns solid black for a few seconds, then the color slowly returns to normal. It seems like he does this when he is aware of movement inside or outside the tank. Does anyone have any other observations regarding color changes in a bimac?
Also, sometimes his mantle seems to inflate/deflate quickly and drastically for a short time. What does this mean? I think he may do this when he is extracting a hermit crab from its shell under his webbing.

Thanks Alot, Matt
I believe that for the most part, white is scared, black is upset (pi$$ed), and any combo of grays and browns is just for camoflauge. Different textures are for camo and I'm not sure about inflating of the mantle.
I think the "big octopus" look - inflated, with eye spots glowing, is to frighten and intimidate. Maybe he's afraid of something and wants to warn what might be attacking.

I was surprised to see so many different hunting colors, too - some to match the background, and some quite a contrast. Sometimes hunting is done with a flat color, like sand color.

Interesting, isn't it? I'll continue to observe.

I've had this bimac for a week now. The first two days he stayed hidden, then started to come out in the mornings and eat a hermit crab. Now he is visible pretty much all the time I'm watching for him. He stays in the live rock but can be seen, usually with a couple hermit crab shells laying empty beside him. How much do other bimacs this size eat? (about 1.5" mantle, 5" total radius w/arms out)

Thanks for the replys, Matt
Hi Matt,
When he was that size, Ollie would eat several ghost shrimp or maybe a small snail each day. He showed no interest in hermit crabs.

Hi Matt!

Did you get him from Fish Supply? Maybe he's part of the siblings??

Ink does not do color changes as readily as Hermin did. Don't know if it's because Ink is mellower? He does flash colors when He's hunting and I have seen him change to the coloring of whatever he's near, blending in perfectly! Sometimes, it takes my 5 year old daughtor to find him, he blends so well!

Anyway, Ink has been eating Fiddler Crabs from day 1! He's seems to like the males with the large claws the best. He also eats frozen prawn, crayfish, those red claw crabs, and soon :smile: I will be able to start collecting locally!

Good luck with him!!!


He is from Fish Supply. Jack said he had been there for about two weeks on May 1 when I ordered him. He must be getting more and more comfortable because it seems he eats more every day.

I looked on the Octo Database and found you've named your little bimac Ringo.

Ringo is one of the bimac siblings, since he comes from Fish Supply - we're pretending that all the bimacs from Fish Supply are brothers and sisters (they could be, after all), and we've been posting their pics and stories on the Journals and Photos forum.

It's nice to welcome one more sibling!

Hi Sideways,

I had a look at the database plus some of the messages.
This is the list I came up with - if I've forgotten any sibling, please let me know!

Ringo, Ink, Tralfaz, Roxy, Ollie, Sam, Vadar

I believe that Turan is also a sibling, and Girlfish's new bimac doesn't have a name yet.

That would make 9 - a good-sized little family. No wonder it's hard to keep track of them all!


Shop Amazon

Shop Amazon
Shop Amazon; support TONMO!
Shop Amazon
We are a participant in the Amazon Services LLC Associates Program, an affiliate program designed to provide a means for us to earn fees by linking to Amazon and affiliated sites.