Got an octopus the other day as an "assorted" species and it was small enough to put into a Top Fin 5 gallon all in one aquarium. I have reviewed a few species descriptions but am really not certain as to what species this one is. I do not know where it came from which further complicates identification but it does seem to be a young male that is no more active at night than it is during the day. The octopus can stretch out across the tank but its abdomen is only maybe an inch at most in length when elongated. It's about the size of my 8 year old daughter's last digit on her index finger (and she's very small). It often exhibits cirri above its eyes and sometimes along its body (pretty interesting as they sometimes look like foraminiferens). It does not have any eye spots that I have been able to see and sometimes seems to exhibit a very slight bluish tinge to the skin, but this may just be a reflection of the light in the room. There is no red coloration that I have seen, either, which leads me to believe that it is not a nocturnal species. More often than not it's a tan coloration except when its eating at which point in time it turns a nice black color. It does not exhibit much if any fear (it has inked 2x out of the blue when we walked up to the tank but if we are there it is more curious than anything else). It does not hide at all but hangs out on top of the rocks or on the glass. It often is up at the top of the water and sometimes sticks its eyes out of the top to take a peek around. It carries one of its arms curled up for the most part, leading me to believe that this could be a male, but I have not seen a hectocotylus to verify. Suckers on the tentacles are paired and uniform and the arms seem to be fairly rounded, although with such a small octopus this is hard to see. It does not seem to exhibit a very large mantle. I have more or less ruled out Briareus and Joubini, both of which seem to be available through the wholesaler (same as liveaquaria from what I understand) and although it does resemble a few photos I have seen of aspilosomatis it does not resemble the majority of the pictures I have seen. Some more factors that may help in ID are that it often exhibits raised eyes. It also sometimes has a striped pattern across its body. Honestly, it looks more like a cyanea but I don't think that this is what it is. Pictures to follow.