Tankmate List


O. vulgaris
Nov 15, 2009
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So I have a potential list of tank-mates for my future octopus.

What I am looking for is simply an answer to the question of whether any of these pose a potential threat to an octopus.

The List Includes:

Green Striped Mushroom
True Green & Blue Bullseye Mushroom
Orange Florida Ricordea

Serpent Star
Brittle Star
Chocolate Chip Star

Would any of these be dangerous to the octopus? Ignoring possible coral reproduction.


Staff member
Sep 4, 2006
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Gainesville, GA
I would have hesitated on the orange ric but I put one in the tank that Tatanka has because it was not doing well in another tank and left it there with the hatchlings and now with Tatanka and have seen no signs of any problems with either the octopus or the ric so my single experience is that, at least the orange ricordeas should be on the OK list. Most mushrooms are fine (and possibly other rics) but be sure they are well established before adding an octopus. I have had three briareus try to pull up one of my red mushrooms that grew in front of a cave entrance. I have change the rock work so that the cave is better exposed below the mushroom but saw Tatanka pulling on it the other day. I know it does not sting her and the mushroom has survived numerous octopuses. As an aside, I have found Kent's Coral-Vite to be an excellent vitamin supplement for mushrooms.

I would avoid the Chocolate Chip star. They are aggressive meat eaters and are known to become problematic as they age. I have not kept one because of issues I have read about from others just in a coral and fish tank so I have no direct experience. I would suggest reading about them from people who have had them for more than a year on a reef forum.

Avoid the green brittle/serpent, eventually they become aggressive (ours was over 4 years old before he had to be put in another tank) but all the others I have tried have been great tank mates. We particularly like the orange (sometimes called red) brittles as they have their own personalities, seem to be especially active with octos. The orange brittle in our non octo tank I see once every three or four months, when there is an octo in the octo tanks, I see the resident "Pesky's - Pesky and PeskyToo - nightly and sometimes during the day).

I would add some kind for rock scraping critter to your list. Pencil urchins, snails (often needing to be replenished) or a cowrie. One other member has had problems with the cowrie flooding the tank with slime. I don't know if the colder water (bimac keeper) or just the nature of the octos makes a difference but I am particularly fond of the one in Cassy's tank for its rock cleaning ability. Pencil urchins can start eating corals (some types of gorgonians will be ravaged in a day) if they don't find enough food on the rocks but they do a good job of keeping the rocks clean and are not dangerous to the octopus.

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