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Octopus tank mates...

Oct 13, 2005
Hello all! I would like to convert my 75 gallon reef tank to an octopus tank, but I have a few issues...

First, I have a few tank mates that i'm not sure I could part with...such as my blue hippo tang, and a mandarin goby. Now, I know that the mandarin would be food, but what about the tang? Would he pick on the octo, would the octo kill him? I really want to get a briareus from MarineDepotLive. I think that it being a 75 gallon tank, it would give more room for errors in quality, more room, etc. The tang is a smaller one (about 2 inches) but he is very fast, and I think he could get away from an octo. Especially since the tang was there first. I do have some hermits, snails, etc., but i'm not extremely concerned about them. I could move my corals to the 20 gallon frag tank, or just leave them in this tank. I know that they cna sometimes move corals around, and disturb them, but I'm not sure this would be an issue, as the corals are large zoa colonies, and if they do, I could move them to the 20. LMK if this sounds alright.

Brock Fluharty;79117 said:
Now, I know that the mandarin would be food, ...

I just shot this photo of my sleeping goby and my sleeping cuttlefish. They are in the same 30 gallon. They are touching each other - (it isnt a depth perception thing.)

I actually had a 3 spot damsel that the Octo (bimac) didnt eat that would grab live fish and drag them down to the octo's lair. He would eat the bits that floated away as the fish was eaten.

Both of these are NOT the norm, and I would have said never happened if I didnt see them with my own eyes.


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It depends on the size of the octo and the individual in general. I would guess the goby to be eaten shortly. The tang is a toss up. Ive kept octos with tangs before. Some octos will constantly 'try' to get the tang and fail, another of mine, would eat any fish i put in regardless of size, and my current one wouldnt even think of it as food.

If the octo is small, it may not be a good idea for the tang may pick on or annoy the octo. Tangs can get territorial. They may not be able to do much harm, but they will turn the side with thier spike hanging out and create a wall and bully the ceph by trying to push it away. No damage is done, but it can stress them out.
I think the point trying to be made here is that every octopus has its own personality and you don't know how the tang is going to react to a new resident. So you can't know until you try to put the two of them together, there are too many variables. So if you leave the tang in the tank, you are taking a chance of them not getting along. No expert can give you a definitive answer.
:oops: Sorry... I have some mushrooms and zooanthids that are going to share with my S. bandensis when they move to the 55 gallon and I know of others that have kept soft corals and cephalopods together. The octopus might move them around...I guess you could just see what happens and then move them if you need to. The only problem I could forsee is the octopus causing the corals to fall and injure the octopus.
Well, they are large colonies, but like I said, they are all naturally attached to the live rock because of growth. Will my 216 watt T5's be way too much for him? I really would like to keep corals with my ceph. I saw someone over on RC that got an octopus as a hitchhiker, and I believe he had MH's, and a ton of corals. His octo was pretty large too. I believe O. vulgaris...

Also, I have a maxima clam, which I am assuming he would immediately eat? I hope not...
Let me start out by saying that I have never had corals with octos. But I can tell you that it shouldn't matter if the rock is stacked or flat, because if they are small enough for him to move, they will be dragged all over the aquarium.
Think of octos as saltwater oscars- with arms.

My opinion is that they wouldn't bother the polyps if they can't move the rocks.

Depending on your tank size and layout the lights could work if he had places to go to get out of the light. I do think that he may hide more because of it. Dan is playing with his cuttlefish and mine hides all the time. I think the difference is that I have MH lighting on my 30 gallon, so he stay in the caves. (or maybe Dan is more likeable. :cry: )
Hmm...this could be an interesting experiment with lighting and octos then. If I had another 48" tank, I would just switch the brighter lights to it, but the longest tank I have is a 40 gallon, which is about a foot short. I don't want to sell this fixture, so maybe i'll just put the NO flourescent strip bakc in it from when I bought the tank. I think i'm gonna get the octo from either Marine Depot Live, or Saltwaterfish. Not 100% sure yet, but i'm leaning towards MDL. I need one that is active, and out all of the time (well, the majority) as I have about 100lbs. of live rock in this system, so if he wanted to act like a dwarf, he very well could. I'm going to have to move my clam, YWG, blue green reef chromis, and blue tang (possibly).
Ok, well I am going to put him inside one of those little pladtic critter trail things, with holes drilled in the sides for circulation, and see if he looks to be stalking the blue tang from within the smaller cage. If he does, then the blue tang is moving to another of our tanks. I've decided to move all of my corals/inverts to a 20 high that i've had set up as a small frag tank for a month or so now. It should make a nice mixed reef from zoas to SPS. I'm going to stack the live rock in a back corner, so I will have plenty of options for toys in the open space, and he can roam wherever he wants to. I already have some seashells in the tank, but i'll get some more. I'm going to make him a den out of PVC with live rock glued all around in. I want it to be vertical, so he comes out of the top of it, but I realize this may stress him. I'm starting to get creative with toy designs, and water bottles...:biggrin2:


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