• Looking to buy a cephalopod? Check out Tomh's Cephs Forum, and this post in particular shares important info about our policies as it relates to responsible ceph-keeping.

Blue Ring Octopus


Mar 21, 2004
Hello, I am seriously considering getting an octopus. I have done a lot of research and currently have a 20 gallon saltwater tank with a few clowns and tangs. My first question is, is a 20 gallon tank large enough for any species of octopus? I have plenty of live rock and hiding places, but will one outgrow this? And my second is about the Blue Ring octopus. I understand they are very venomous, but besides that what is there major downside? Are they harder to keep or shorter lived than an average octopus?
A 20 gallon would only be suitable for a dwarf octopus such as O. joubini or O.metocaris.

There are more downs than ups to keeping blue rings, they have a short lifespan (so does the dwarfs) or about 6 months from birth and most of the blue rings yyou get will be adults.

They are nocturnal like dwarfs and only display their blue rings when threatened or excited. Note that stressing out the octo just to see the rings will lead to a short death to it and possibly to you if it bites you.

We don't recommend keeping blue rings since they're one of the top 10 most venemous creatures.

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