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Getting Bimac, Questions


Oct 1, 2003
I just placed an order for an aquacultured bimac from liveaquaria.com for Friday delivery. Aside from being a little too excited for words, I have some questions. I asked some of these on reefcentral, but this is the octopus place, so I figured I should probably also ask here.

First, I had a pygmy for about six months who died this past spring. Since it was full grown when I got it, I assumed it lived out its natural life span. So I can at least say I have some octo experience, even if not much.

I want to start this guy in a 20 gallon because of its size. I have a 38 gallon not in use except for some salt water mollys that I'll probably make its eventual home. So two questions. Is the 20 gallon too big for such a small octo (between 3/4 to 1.5 inches). And will a 38 work for a final home? or should I be looking bigger?

I am thinking it would be fun to attempt to breed octopuses; because I believe that propagation is the end goal of the hobby. At least a goal for myself. Should I be looking to change my order to more than one, or can I add another at a later time if I feel comfortable in breeding them. Is it a mistake to only get one now? I am under the impression that bimacs are pretty tolerant of other bimacs. But I'd rather not do more than one until I'm more comfortable with them.

The 20 gallon I am thinking of placing it in has two powerfilters running on it for lots of water turn over. Should I worry about covering the intakes in addition to the normal covers? An octopus wouldn't get stuck in/by the intake tube, would it?

Right now, there are two saddleback clowns and a cleaner shrimp. One clown is 1 inch, the other is about 1/2 inch. The cleaner is 2 inches. I'm afraid that I might not be able to catch them. I'm not as concerned about the current inhabitants getting eaten, but could they hurt a small octo?

Being aquacultured, is it likely to take frozen straight away, or will I have to train it onto frozen if it accepts it at all? I'd really enjoy the convenience of frozen if its possible. My pygmy only ate live food, and for such a small guy, rang up quite a food bill.

I look forward to your responses![/i]
Hello Fishgrrl,

First of all, welcome to TONMO.com! Yes, this is the octopus place, but we try to provide information about all cephs.

As to your questions - some people do use a smaller aquarium to start with, like a 20 gallon, but even a small ocotpus is a messy easter, so make sure you have good filtration.

At one time we believed that a 30 gallon tank was enough for a bimac. I now think they need larger tanks. My 46 gallon is barely enough for my adult bimac and he would be far better off in a larger tank.

Bimacs are not particularly tolerant to each other, and we have had instances of one baby octopus eating the other. I'm waiting for the first report of two raised together - some people were trying this.

Aquacultured octopuses are raised on live food, as far as I know. Look at the Buy,Sell, Trade forum and you'll see a posting for someone selling both octopuses and food. Your bimac may learn to accept frozen food later.

Your cleaner shrimp is destined to be lunch for your bimac when it's a little older. Sometimes an octopus will accept another creature as a tankmate and not eat it - you never know. We tell people to remove fish from their tanks when getting a baby octopus.

I hope you can post something more about your pygmy octopus - what species, if you know, what it ate, were you able to interact, etc.

All the best with your new octopus!

Welcome to TONMO. Nancy did such a good job here that I wont bother replying on reef central like i nearly did LOL glad i checked first!
Thanks for your response! I guess I'll be going fishing today. I don't look forward to catching the fish!

What do you think is a good "end" tank for a bimac? A 55? Does it need to be a standard shaped tank or could I use a large corner or a large hex with lots of vertical rock work?

Regarding the pygmy, I don't know what species for sure, but it was suggested it was O. mercatoris. It prefered to be a rather reddish brown most of the time. It was definately nocturnal and not very fond of me although it recognized the difference between being observed and feeding time. I think it recognized me peeling the tape off its aquarium lid to feed it. :smile: It never came out at feeding when I was around, but would become interested, peering out of its den.

I really only saw it out a handful of times. It would only come out when all the lights in the room where out, meaning no red nightlight!! I actually started watching it at night with my husband's nightvision. :smile: It would often sit just inside its den though, sucking on a hermit crab shell.

This is largely why I decided I wanted a bimac now. As cool as my pygmy was, I want one I can interact with more. Although I'm not sure I'm brave enough to let it touch me like some people do!!
Another question: I was just reading that bimacs aren't as prone to crawl out of the aquarium. Should I be concerned with finding and sealing all possible exit point or not? I was going to attempt that after I caught the clowns, but if I don't have to, I'd prefer not to.
Yes, bimacs do escape. We lost one this year, and last year one climbed out and fortunately its owner found it in time.

You need to secure your tank, maybe "seal" is too stong a word. I'm using a brick and pieces of black duct tape, maybe 4 inches long. I replace them almost every day. The entire lid is held down by 10 pieces of tape.

Interesting about your pygmy. They're certainly not friendly like a bimac.


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