Help for a starter!


Apr 29, 2010
Hello everyone...

I just joined today and I am interested in hearing advice from some of you!

First off, I am interested in getting a PYGMY octopus, and from what I understand, I need to be looking for an Atlantic Pygmy Octopus (Octopus joubini) rather than getting a baby octopus.

A couple of questions I have are:

What is the BEST sized tank for an octopus of this size?

I've been looking at Biorb tanks that are spherical or globe shaped. Would this be ok for a pygmy?

Does anyone have any good resources for where to buy actual pygmies and not just babies? I have looked over the site thoroughly, but a lot of the posts I've found related to my questions are older, so I just wanted to hear some current opinions on the best sources to buy from.

Also, what, if any, compatible marine life is there for this species? I know they eat just about everything, but what about urchins, puffers, starfish, and anemones?

Any advice for a first-timer would be greatly appreciated!

I look forward to chatting with all of you!


Staff member
Sep 4, 2006
Two of our staff have written a book just for cephalopod keeping. There is a review and link to amazon for Cephalopods Octopuses and Cuttlefishes for the Home Aquarium in the book reviews section found on the home page. The Ceph Care Articles, also found on the home page has numerous getting started articles that will be helpful. Experiences of other dwarf keepers can be found by looking at the List of Our Octopuses 2008 - 2010 in the Journals and Photos forum. The octopus species is listed and is a link to the specific journal. Two older journals that would be of interest are GHolland's history of Varys and her young and my journal of Trapper and her brood.

The most commonly kept dwarf species is O. mercatoris (often incorrectly labled joubini). These are a nocturnal animal and will not acclimate to daytime activities. The ones we see are from either the Gulf of Mexico or the south Atlantic (often from the FL Keys). I recommend trying to source one from a direct or indirect collector in South Florida as most know how to identify them. TONMO member DantheMarineMan sometimes has them available as bi-catch found in their live rock and TomsCaribbean often has them as bi-catch from the crab and shrimping industry. Additional occassional direct bi-catch sources are Sea Life Inc and Island Marine Life

IMO, a biorb is not going to work for most marine life (and is only recomended for FW). I have converted mine to SW but use it for anemones, sponges and a single mantis shrimp. I have completely removed the filtration and use a circular air tube to ensure enough CO2 exchange and change out 5 gallons of the 8 weekly. IMO there is nothing you could do to make it appropriate for an octopus as the waste load is too high and the filtration totally inadequate.

Next, octopuses don't eat just about everything in spite of what you hear. A proper diet will consist of primarily crustateans (for a dwarf, shore shrimp and fiddler crabs and sometimes they will eat snails and/or hermit crabs. My current merc will take small pieces of frozen grocery store shrimp but none of my others would accept it). Fish are not a wise choice as tank mates. They do not provide a good source of food and will generally become food (or at least be killed as a threat) or harass the octopus and make it even more timid.

Avoid putting any animal in the tank that can damage the skin (either by stinging or by puncture) as skin damage can easily lead to infection, often resulting in death. Most caribbean sea, serpent and brittle stars are acceptable (avoid the green serpent) if the aquarium will support the starfish. Pencil urchins have mostly blunted spines and can be used but other urchins may or may not be problematic (the rocks have very sharp spines that will break off and embed - taking forever to come out of a finger - and the pin cushion's velcro like attachment can be an issue).

All octopuses need exaggerated CO2/air exchange and heavy filtration. A skimmer is recommeded even for a merc. Water volume depends upon your maintenance habits. I have successfully kept a pair in a 15 gallon with a skilter combination filter/skimmer and 5 gallon weekly water changes. A 20 gallon or larger is suggested if this maintenance schedule needs to slide to every two weeks. Anything larger than a 35 gallon makes it difficult to observe them. I have an unofficial write up on tank suggestions and personal recommendations for housing a mercatoris if you will PM me with your email address.