[Octopus]: Ocho - A. Aculeatus Finally received a octopus


Apr 1, 2007
Hello all finally hunted down an octopus. The owner of the fish store told me when asked where the octo was from said it was probably from Atlantic. Any help would be greatly appreciated!! Thank you guys for always being a wealth of knowledge and helpful information.


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So cool! Be sure to start up a Journal for this guy!
Thanks for sharing the great pics... I'm sure our resident experts will be by soon with some thoughts.
...I'll try to goose some input via FB.
(edit: done.)
He/she is missing half of an arm on the front left I believe. The mantle is only about maybe an inch long. I am worried that the octo is stressed out from the pet shop and I can not find a ton on the forum on arm loss. It is active and searching around the tank, I have not tried to feed it. My pH is 7.8, sp 1.025, temp 72. I just do not want to stress it out. The shop said it was feeding on live pepermint shrimp. Just worried it loss it arm due to stress or possibly other reasons. I have no hermit crabs in this tank.
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I can not find a ton on the forum on arm loss
I found this hard to believe when I read it, so I tried a search on "autophagy," and I was surprised to only find a few responses...

So, I checked settings, optimized mapping and rebuilt the cache, and now have 7 pages (120 results) on that term. Here's that search: autophagy
Do you know if the arm damage occurred before or after you placed it in the tank? Virtually all octos we take in as pets are from the wild and will have lost parts of arms before being placed into a non-predatory environment.

Arm loss will generally occur in one of four ways (order of expected frequency).
  1. Predation - arm bitten off by any of a number of predators (pretty much any thing that swims and is larger than the octopus)
  2. Defense - arm discarded at a specialized section to avoid predation or entrapment.
  3. Autophagy - self immolation caused by damage and or stress
  4. Autophagy - self immolation caused a bacterial affliction (the bacteria not yet identified but anecdotally is considered contagious).
In cases 1 and 2, you do not need to be concerned if it occurred before you acquired the animal. The arm will grow back and there is no real harm to the animal (assuming the animal is not in the last stages of life. A senescent animal's tissue will not recover but the animal is in a dying state and is the least of the impacts on its health).

In case 3, sometimes the animal will recover if self consumption is stress related and the stressful condition is eliminated.

In case 4, the condition has always been observed as fatal but is unlikely in this instance.

From your pictures, I am guessing that it is NOT from the Atlantic, but rather imported from the Philippines general area and is likely in the Abdopus complex. Use the search term Abdopus in titles for both journals and images of octopuses we have identified in this genus (many are assumed aculeatus as the species).

Aculeatus is a medium sized diurnal, small egg common octopus (sometimes referred to as a Bali octopus). However, there are an unknown number of similar looking animals in the Abdopus complex. Some are much smaller, some are nocturnal. We are not sure how many are not yet described.

Lastly, your PH is very low for an octopus. I would recommend slowly raising it to at least 8.2 through water changes (your new saltwater should be registering in that range if you are using RO water and a commercial salt). You may want to add buffering for awhile until your tank maintains the higher PH. DON'T try to raise it all in one day but work on it over a week's time the monitor it and add buffering to your NEW water if needed (not directly to the display). If you have a sump, you may want to add an air stone (again, not recommended for the display tank) to encourage additional release of CO2.
I have looked at the videos I took when she was in her bag and it is clear her arm was not there before going in the tank. Thank you so much for giving me some tiny relief. I will keep an eye on it and update you guys in a couple days. Thanks!!!!!
a search for "arm loss" (no quotes) returned 3 pages of results... I'm not sure that was the case when I tried it yesterday... possibly, our search function is acting a bit strange... will keep an eye on it.
:periscop: :feet:
I thought I noticed a short arm in the video but it was not clear it was the same one that concerned you. You might enjoy watching the regrowth process. Initially you will see a tiny string develop from the end. (The first time I saw this I wondered if it was dead tissue that should be removed :oops:wink:). Slowly you will start to see tiny suckers along the string. It will start to fill out to the width of the original arm as it lengthens. Depending upon the age of the animal, the damage may ultimately be invisible. Often though there is a slight miss-alignment of suckers at join or a slight thinning. With the species I suspect, it will be hard to observe (because they move more than hold still) but you can try to find older arm regrowth when you sit and observe it. Look for one arm in a pair (pairs start at the front an are traditionally labeled L1-L4 and R1-R4). L (left) being counter clockwise as you orient your eyes to the octos. For hobbyists, regrowth of lost arms can easily be detected where you see unmatched lengths in the pairs. Different species of octopuses have different pair arm lengths (and sometimes thicknesses) but the pairs will be consistent with the exception of (usually) R3 of the male. The hectocotylus is typically shorter, has a suckerless tip (ligula) and is usually kept protected by being curled when walking about (photos and a bit more on sexing can be found in this thread).

Be sure to read my full initial response as I included a bit more species suggestion info with an edit.
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Small update... Ocho is doing very good active and out a lot and feeding on live fiddler crabs. His/hers missing tentacles are beginning to grow back and it is pretty cool watching it happen. I am still trying to dial in my protein skimmer but other than that the water parameters are pretty solid. Thanks again for all the help! I have been a long time lurker and finally getting back into the hobby but plan to be active on the site.
Yes that is fine DWhatley. Thanks again everyone she has been feeding and very active. I am cycling a 100 gallon tank to move her in eventually. I will post some new arm growth pictures soon.

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