If you want a dwarf octo, Expect to see it literally once in a blue moon, also, it WILL likely eat everything you have in that tank. Abdopus aculeatus is the only octo out there that I've heard will get along with tank mates. However I would expect all of the shrimp to get it and the chromis is so small that it will probably get it too. Larger fish such as foxfish or tangs, etc that are VERY peaceful will probably be fine though. Also, I see in your signature that you have a 29 which will be too small for all but a dwarf, which I don't suggest because, as mentioned above, they will eat everything you have listed and you will never see it.