• Looking to buy a cephalopod? Check out Tomh's Cephs Forum, and this post in particular shares important info about our policies as it relates to responsible ceph-keeping.

Do Hiding Benthic Octos Prefer High Spots or Low? (Possible O. Merc Escape?)

wasitgreen

Hatchling
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Joined
Nov 21, 2011
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6
I ask because my O. Mercatoris (acclimated 11/21) somehow escaped from his mini enclosure and is now somewhere in my main tank, I think either my dog spooked it at night or it was my constant checking on him to make sure he's ok (first Ceph so trying to spot anything worrying in advance) but anyway, I started to check on him less to give him some time alone (by the way I just take a peek at him, I'm not moving his hiding rock around or anything) and he somehow, at least I think since I can't find him (and just to be fair thinking now, I only had 1 rock and macros in there because I am picking up an order of new rock just for him today), escaped through < 1/4" slots and into my main. While looking for him it occurred to me that he liked to be high up in his rock in the mini tank, but the fact that he is a benthic octo, it would make more sense looking near the sand? Also if there is any tricks to get him to come out so I at least know he's safe and in there please share. He should be safe as I am turning off powerheads and screening the top in a few hours, however I have concerns over him getting stressed by a curious lion, who thankfully is small enough to be just bigger than the octo, and small/passive enough to leave my Mandarin alone. While my skunk cleaner may pester the poor octo to death trying to clean it (if it hasn't been made into octo-lunch yet). I'm thinking that even though he is nocternal, I will be able to see him at lunch time when I put some ghosts in there as he seemed to like them eating 2 or 3 with in 15 mins of introduction, or are they really just that good at hiding? He only seemed to be able to display limited color/texture changes in the black/grey/white range. I will also add that I wasn't fully expecting him to escape and didn't really prepare for it (99% sure the slots are smaller than the beak and being the idiot I am, I didn't prepare for a worst case). Sorry for the rambling, just trying to make sure I told all the info I have. And although this seems irresponsible not preparing, this is why I located an older, smaller octo, to see where problems would arise, make sure water is fine, check his stress and see if I can acclimate correctly, what to do if there is an escape, and worst of all, see if I can handle to short life spans that cephs have. All of this info will help me when I dedicate a 55-65 gallon to either a O. Briareus or A. Aculeatus in the future. Thanks all!
 
I usually advise that critter keepers are only good for about a week or two, the octos WILL escape them (multiple occurances are recorded).

I hope your "black" is really a dark reddish brown or I am misguessing species. I don't know of any that turn black (deep dark brown is common) but the merc dark color always has a ting of red. That being said, few people ever describe colors the same way and limited color and patterning is typical so I will stick with my guess.

My mercs all chose middle ground for denning, guestimating at about the lower 1/3 of the tank. If you can find a purple barnacle collection to put a couple of inches off the substrate, you might entice it to den there but the males I have kept moved dens every week or so, even with the barnacles available (the females took ownership and kept them all their lives).

Yes, they are very hard to find and in looking you will discover a lot of "octo rocks" :wink: I find two things helpful. One, look for white suckers but they look much like artifacts in the LR so you may find several. Two take several pictures of your tank and look at them on the computer. I have seen many things in photos that I don't see when looking into the tank. That being said, mercs are particularly good at going into crevices in the LR and not being visible at all. If you can set up a red light over even part of the tank, feed around 11:00 PM with all ambient lights off (red light on) and sit very quietly (ie no movement) for perhaps 30 minutes you may see it. If you can do this regularly you may be able to hand feed but it takes time and lots and lots of patience.

I have not kept mercs with any exposed impellers (not even the Koralias that I keep with other octos) so I don't know how curious they are around dangerous equipment (mercs are the least curious of the ones I have kept). Even though my Koralias have been successful without covering, I now keep a mesh zippered bag over them since my larger animals like to use them as a shedding tool.

I have not kept fish with any octo (and that is my recommendation) so I don't know how safe the mandarin will be. Older, well fed mercs have ignored or been unable to easily catch the shore shrimp so your cleaners have a chance.
 
You are right on the color, he is a deep reddish brown, it just looks black due to my glass being wet. I did find him (in almost exactly 1/3 of the bottom), thankfully, he was in a hole my emerald used to frequent with a "shell-door". I am going to try and move him after I can assess the new rocks I am going to pick up. I am for sure going to pick up some meshing, though I in an hour or so when I go to get the rock. I also am having a 2-toggle light when I get a dedicated octo tank for next year I hope. Thanks for all the info, I hope to stay around and learn to better keep these awesome animals!
 
If you can find a media bag with a ZIPPER (not velcro and NOT string) with fairly open holes and will fit around whatever you are shielding, they work really well to shield impellers and the like, can be relatively easy to clean, don't need modification and allow water passage. I discovered using them when I had hatchlings and just left them on the Koralias.

Most embarrassingly, I forgot to mention looking for a shell in an odd place, particularly one that will not fall off when you try to pick it up :oops:
 

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