Orange - O. briareus Teacher Kim's New Octopus!

OK, hopefully you are going to see the best pic I have of our new octopus. It is a lot bigger than I expected! Maybe I just don't know what a 1 1/2 inch mantle looks like!! Am really hoping it's not full grown and going to die soon, but we will see! I put it in the 50, but it looks like I may have to move it to a 125 or ???

Am really interested to see what opinions are as to identification and possible age. Diver Tom seemed pretty sure it was an O Briareus (sp).. Thanks!!


I am far from an octopus ID expert, but I think I would agree on O. briareus, based on the fairly extensive webbing visible in Pic 1, long arms and that slight greenish tinge around the arms in Pic 2.

On the first picture that mantle looks a bit funny - the constriction and bulge at the base looks abnormal to me - but maybe that's just a momentary thing the camera happened to catch?


Staff member
Definitely O. briareus. That lump look at the back of the mantle is puzzling. A couple of additional pictures would be helpful to see if it is an artifact from camera. The back of the mantle will start swelling when eggs are developing but this looks more like a lump than what I have noticed in my females.

I can't get a clear prospective on size. On my hand the first joint is close to an inch and 2" at the bend for the knuckle. The mantle is measured from just behind the eyes. If the perspective is not off, and your hands are similar to mine then I am guessing 1.75 - 2". A large briareus can have a mantle up to 5" but 3" - 4" is more what we see. Octos vary in size greatly so you can't tell much about age.

She will not grow extremely fast at this point but the never stop growing altogether. The 50 is going to be small for most and this species currently has the highest availability so I would suggest getting the larger tank up and running soon. :wink:
She made it through the night (I always worry.) and after slowly increasing light she is now sticking her tenticles out through holes in the pile of live rock she's under! Looks very healthy and active from what I can see. That bulge in the one pic is just something the camera happened to catch! Crazy!! I was trying to coax her out of the plastic bag. I decided to cut bag open and just let her leave it on her own.

Her arms are interesting. One is growing out from her mantle. Really cool for the kids to see! At least 2 others are long with what looks like tiny new growth towards the end. New growth is thin compared to rest of arm and about an inch or so long. At first I thought this meant it was a male, until I saw same thing on arms other than 3rd on right. So.... can we even tell if it's a male or female if that arm is damaged?

The tank I am going to move her to is a 125 that is already up and running. I would just need to relocate a few fish. Am also going to start looking for an even bigger tank. I have been looking at a really cool used 200, but it is taller than it is wide. Am wondering which is more important, height or length? Will put up another pic when I get a good one! Thanks!


Staff member
IMO, DON'T GET THE TALL TANK unless you are a glutton for punishment (not a problem for the octo). I have 3' tall and 4' tall tanks and cleaning them is the pits. When someone is looking at tanks I always recommend checking to see if you can reach the bottom as the tank will be set up (so in some cases this includes a hood height).

I am glad the lump is a camera artifact as it worried me a bit. I am wondering if it caught some of the biologics though. I will be glad when you make a good sex ID to see if there is something to the candling affect. Based on that thought I am guessing female but we have not seen this effect before so that is just an impression. The arm you want to observe is the third arm to the right clockwise as you position your eyes with the octopus'. None of the other arms (in all most all cases, there have been some odd exceptions) are going to tell you anything. Losing an arm does not change the biology and the hectocotylus will have a channel running the length of the arm (more easily seen in photos than with the naked eye). The tip will regrow without suckers and have a different tip but the biggest give away will be that the arm is usually carried rolled up. We named SueNami when she came with the third arm completely missing. As it grew back, it was clear we had a boy named Sue :grin: Initially we conjectured that this arm was the most protected so the octo must be female, later we decided that he may have lost it in a mating attempt. All second guessing of course :roll:.

The regrowth of the arms should be a very good interest point for the kids, especially if you can get her to feed when they first come to class in the AM as you should ultimately be able to get her to reach for the food so you can see the arms thicken and catch up to the others. The octopuses that come from Tom are usually brought in from crabbers and this is stone crab season in the Keys. If you have eaten stone crab claws, you will note that they are quite strong and can intuitively understand why the octos are in arm regeneration all the time. Additionally, when you see this species hunt, it is clear that they lose their arm tips to anything hiding in the rock in addition to natural predation instigated by other animals.

She will take awhile to start coming out but live food will help (in addition to a regular feeding time). If you can get your hands on a live shrimp or two (bait shop is your only bet here I think. They should survive fairly well in the other tank and not be too hard to catch) you will likely get a nice show of the webbing and full body. If you will go to my YouTube channel (dwhatley_GA) and search for: shrimp, there are a couple of videos of this species attempting to or catching their shrimp dinner. This species seems to have very far sighted vision and does not see well close up so the shrimp allows them some hunting time in close quarters.
Oh cool! Thanks for comments! "D", you are so right about height of tank!!! I have one tank that is a pain already! Not sure what I was thinking! LOL!! Will keep looking! :) Am sure 125 will work at least for a bit! It's a really nice old fashioned long one. It's actually easier to clean than the 50!!

For now I will call it a she! She definitely has a spot she's using as a den. She sticks her arms out of it every once in awhile and feels around all over! So different from Ziggy! She took a thawed fiddler crab this morning, but later I watched her practically throw the whole thing out of her den! Too funny! Happened too fast to get video. About half hour later she took it back inside and I haven't seen it sinse. She is also moving sand out from her spot. She pushes it out through the lower holes in the liverock! The only other thing I saw was, while still in her plastic bag in bucket, she curled up all her arms in the same way and kind of shook them all at the same time. She kind of looked like a wind up toy vibrating up and down! I have no idea what that meant!!

As far as the lump on top of mantle, I haven't seen it since pic was taken. Actually, we never saw it at all until we looked at picture, so it happened pretty fast! No new pics yet, but have camera ready just in case!! :) Will check back in tomorrow! Thanks to all!


Staff member
Is this the arm behavior you saw (watch the whole video). This has been called grooming behavior but IMO it is closer related to stress. Sometimes you will see sucker shed when they do it but I don't think it is a primary gooming movement in spite of other determinations.

Hopefully the sand moving is just to make a comfy den and not making a brood den. Either way, it will be an interesting experience of course but I hope you have some time with her before she broods. In addition to somewhat faster acceptance of humans an advantage to getting this species after sexual maturity is the potential to raise hatchlings. Definitely box of good chocolates, regardless of how it all turns out.

PS, my camera lives next to my octo tanks on a tripod in the corner.
No, or maybe a yes, no, I think there was a major difference. When she did it she was sitting flat on the floor of the bucket and curled up each arm, all looking exactly the same and then kind of bounced/vibrated straight up and down quickly with her entire mantel centered and completely exposed. Probably lasted 2-3 seconds and then she stopped. In the video I watched, arms were curled in different directions and covering the mantel. This was amazingly cemetrical!! Would have made a perfect picture for kids of something round like a circle!!

More to report.... Let's see... she is doing the fishing line thing where she sticks her arms out and kind of leaves them out until something wanders by! Last night she threw, and I mean threw, a bristle worm out of her den! Then she threw out the remains of two fiddler crabs she had eaten the underside out of! So at least I know she's eating!!

OK, I am also thinking that you, "D", are once again right!! I went back through pictures carefully this morning looking at mantel. Am going to put one up that shows a slightly round area at top of her mantel. Not all pics show this, but it does prove that it happened more than once while we were snapping pics.


OK, sorry everyone!! I am so not good at this computer stuff!! The above is the correct pic, but I thought it would be larger so you could see the mantel better. But nooooooo! I somehow put 2 pics up of the same thing! LOL... I gotta laugh at myself, or I'd quit using computers all together.

With that said, I am going to post a pic of when the kids first saw octo when it came out of box. The one little boy got soooo excited! :)
Moving on.... I think that maybe the new octopus is a female that has mated. My husband, Kevin, is going to put his go-pro up on the tank tonight!! YAY! Hopefully tomorrow we will have something to really study as far as her mantel and arms. If she's going to lay eggs, I will do my best to keep the young alive as long as possible, but will need lots of advice! :) To be continued tomorrow..... :)


Staff member
:lol: Slow down :wink:
The mantle is too small at this point to expect brooding, it simply looked odd in the one photo. You cannot tell visually if she has mated as the eggs are fertilized (we think) at the time they are laid with sperm that is stored until it is ready to be used. Typically, you will see the back of the mantle widen and she will have difficulty controlling it. During this time she will clean out a den (sometimes one she has used, sometimes another). Often you will see prebrood females go between two dens, "deciding" which is the best location. During this process, she will start dragging small pieces of substrate (shells, rocks etc) to the new den to block it from invasion( sometimes the small pieces of substrate are not so small :roll:).

I saw your note on Yeti's journal but Yeti was much younger when she arrived. Better examples might be Kooah (female with viable eggs), SueNami (male) or Kaysoh (female with infertile eggs)

For other journals, go to the sticky at the top of the journal forum marked Lists of our octopuses and scroll down to the more current years then click on the animal names next to animals labled O. briareus. Here is a direct link to the 2012 list.

As far a viewing the pictures, if you will click on the image in the post, it will get bigger. If your browser is set to resize the images, it will be no larger than the original but as big as the screen will display to show the entire picture. If the original image is larger, clicking the image again will size it to the original huge image. I am not sure what you are doing to post the photos twice :grin:
Oh good! Am really hoping she will be around for awhile! Actually, am interested in Yeti to get ideas of possible behaviors, etc... that I might expect from this one since they are same type. Am going to check the ones you mentioned also! I'm very excited about the fact that she is so much larger than Ziggy and more active during day, even if it's just arms! LOL! Can't wait to see her come out and hopefully start interacting in future!

Thanks for help with pictures. I have no idea why those pics showed up double! :hmm: I have go pro set up right now so am hoping to see some activity from her in morning! It will record for 4 hours straight! Will report tomorrow!
Note to husband: :mad: you can't get video of an octopus if you only have 10 minutes of time left to record. You must first delete old videos! LOL ! With that said, we have over 4 hours of recording space for tonight, so I am going to cross my fingers. I was so disappointed this morning!!

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