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bimac is a good choice if you can keep the temperature low enough. If not i would look into briareus or A. Aculeatus, also hummellincki seem to be pretty interesting as well, but they don't seem to fare very well in aquariums. Check the Octopus Availability thread to find sources for octopuses.
I agree... all the hummelinckis that died came from the same supplier at about the same time (within a month or so) so I suspect that perhaps there was a batch that was infected with some disease, or were exposed to toxic chemicals in capture or shipping, or similar. A few people have gotten hummelincki recently, and they seem to be doing much better.
They seem to be relatively sociable, very active during the day. I kept two and they never hid much, but they weren't with me long either. As Monty mentioned, several of us kept them and all had similar results. They didn't live long. They all came from the same source, and some of them had eye problems. The reason for their deaths was undetermined, but we speculate that it was either due to their collection methods, containment after capture, or that they were all already old.
My first one would approach me and grab my fingers without much hesitation and I fed it by hand on day one. The second one had a rotten eye when I got it, and never interacted with me. I will definitely be looking for this species again and hope to find a small one next time.
Watch Dwhatley's video of Octane or you can search for my videos of Tuvalu.