Do you mean he is in the open all the time or that he has done no construction and sleeps in the liverock?
If you don't see your octopus taking a den to sleep this may not be a good sign. I hope I am wrong about this little guy but with the Mercatoris (behaviors are often noteably different from the larger octos), I have observed that when they stay out of their dens all the time it is the last week of their senscence (also an explanation of why so many WC die soon after arrival since they are easier to catch). If your fella is really Briarius, I fear this may be the case since they are naturally nocturnal and untrained, long duration, daytime activity would also suggest senscence. Since he is eating well, hopefully my thoughts are off base.
If, on the other hand, you are looking for an engineering feat and are disappointed that he just slips into the LR, this is not a concern. From memory (no quotable times) I seem to remember den building activity taking quite awhile for younger octopuses. Take a look at the thread on Biddle, I seem to remember Carol saying something about him/her being quite active lately with tank redesign and she has had him several months.
thanks for the replies. no hes not out in the open he usually is hanging on the underside of live rock, still visible but in the shadows and all curled up, he will also hide in a conch shell on occasion. hes only been here afew days though (:
also hes been shedding suction cups for about 3 days now. should i be worried?
one more question. my local pet/fish stores do not sell large shrimp so iv been giving him vitamin enriched silver sliders, are these acceptable as a dietary staple food? for a little variety i was thinking krill, as this is the only other large frozen food item they sell. would an octopus eat krill?
After reading you concerns and now knowing that the octopus is not just out in the open all the time, I remembered a study done observing Vulgaris and Briareius and it mentions that Vulgaris will often build a den where the Briarius will more often take what is available:
file:///C:/Documents%20and%20Settings/Owner/Local%20Settings/Temporary%20Internet%20Files/Content.IE5/0H8W8VYA/An%2520Analysis%2520of%2520the%2520Cohabitation%2520of%2520Octopus%2520Vulgaris%5B1%5D.ppt#256,1,An Analysis of the Cohabitation of Octopus vulgaris Cuvier and Octopus briareus Robson at Bailey’s Cay, Roatan, Honduras
i went out and bought a bag of carbon rated for a 110 gallon aquarium(for whatever reason this was less expensive than smaller bags)....will too much carbon pose a problem in the tank? i havent put it in yet.
Just rinse it well. Yes, leaving carbon that has absorb all it can in a tank is worse than none at all at it will leach nutrients back into the tank. Two or three days is a very short time, however, unless you had only a very small amount. Are you sure you are circulating your water well? The carbon should be in some kind of bag that gets direct flow and not just laying in a sump. Odor is usually a sign of a filtration problem or stuff dying in the tank so please keep a very close eye on your ammonia and nitrites. I would also suggest a water change.
Glad I remembered the study. There wasn't a lot to it but is certainly addressed your concern rather nicely.