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New Unexpected Friend

Joined
Apr 2, 2010
Messages
286
Just thought I'd share,
Someone brought a very small octo into my LFS that I work at, wondering if it was ok to keep in his reef. He found it while out diving. When he discovered that it couldn't be kept in his reef, without causing danger to all his invertebrates, he wanted to leave it at the store. We didn't want it there, as we had no where to keep such a tiny critter, so I took it home with me. I believe it is a dwarf species, but I'll let you guys check him out. I plan to keep him in a 20 gallon for now. But I have plenty of tanks available if I need to move him into a bigger one.

I have experience keeping cuttles, but this will be my first time with an octo. Hopefully all goes well.


 

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I THINK it may be an O. mercatoris but the coloring and striped arm pattern are making me hesitant. Here is the journal for my last merc, Sleazy , a typical merc image in our photos and one of Roy's great detail shots. The second set of photos I added to Sleazy's journal noted as added for ID are the ones that show a similar mantle shape (and possibly age) to your new friend. If this is a correct guess, then a 20 is a good size and I recommend adding a giant purple barnacle cluster about 1/3 of the way up the tank where you can view it but it is secured in the LR. This has been successful for me with several mercs and allows viewing most of the time. Dens chosen in LR often result in never seeing them.

Look for an arm to mantle ratio of around 2-2.5: 1 , the strong tendency to bring arms one and two up over the eyes when denning or in a defensive posture and for it to be nocturnal. There is another dwarf that is "supposed" to be common in the Caribbean and we MAY have seen ONE. Look at Sedna's probably O. joubini, Pandora. There are not a lot of photos as this one is also nocturnal and I suspect they look more like vulgaris than mercs but can't be sure on the id. Pandora's similarity to a vulgaris had me thinking Little bit was also Joubini until she grew too large to be a dwarf. IF Pandora is joubini, the I don't belive this is what you have.
 
Thanks for the info D!
I experienced my new octo displaying the behavior you mentioned with the arms over the eyes. At first, it made me think of a spider, how it shrivels up when dead. I didn't think that behavior was too comforting to see at the time, but this new news is good to hear.
I do have some barnacles I can add to the tank. I'll add those tomorrow.
The octo accepted food very quickly, in fact, he ate a ghost shrimp while at the store.
My first guess on the ID of the octo was Merc, that's even what I told the guy who brought it in. Assuming it is a merc, what do you think the age is on a specimen this size?
My octo in a gatorade bottle at the LFS:

 

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Age is a tricky guess but, particularly with the mercs, I noticed that they turn a dull gray white and are very sluggish near the end. The similarity to Sleazy during acclimation would have me guess an equivalent age but that is stretching it. Mercs can be expected to live anywhere from 8 to 12 months. I had one tank bred male (Wiley) that lived for 13 (but all siblings died sooner and, of course, you don't know the starting age of this one). Sleazy was with me for 6 months but was female so, not very active (the males tend to be out and about at night where the females I have had pick a den and stay there most of their lives). Wiley's journal has some notes and photos about detecting senescence (eating well is a positive health and age sign, BUT a female will eat a lot just before brooding so it can be an aging sign as well).

Something to think about though. If this one is female, there is a chance she has mated. No octopuses are easy to raise from new hatch but the mercatoris is one of the two most successful in home aquariums (O. bimaculoides being the other). Determining sex is not always easy but look for the third arm clockwise as you orient your eyes to the octopus'. If that arm is normally curled up toward the mantle when others are not, then this will likely be a male. Here is a thread with pictures of several species that should be helpful. Females have no over ID traits except, perhaps a misshaped mantle just before brooding.
 
Thanks again D!
I'm not sure which I am hoping for: an older female that may lay fertile eggs, or a young juvenile that will live longer but probably produce no offspring.
I'm not sure on sex yet, as I will have to spend more attention to the legs.
This morning I thought I lot him. The only thing in the tank right now is live sand, a heater, an airline (located at the top half of the tank), and a couple pieces of PVC fittings (Couplings and Ts). I woke up this morning and went to look for my new friend. I checked every PVC fitting but couldn't find him. Finally I found him burrowed in the far left corner of my tank. Whew!
 
Please don't delay in giving it a proper den. Early on, I think I may have ended one's life early by not giving a merc a place to completely hide and I have been sensitive to the idea ever since.
 
As long as she/he can hide and be in the dark it should be fine for the octo. I recommend the barnacle for viewing as they can be placed where you can look in and seem to be quite acceptable to this species (a bit odd since the barnacles are not native to FL and actually come from the Pacific).
 
It is so frustrating when we lose them in the first couple of weeks. After that there are occasional mystery deaths but not many (or at least we see the signs of senescence and assume a natural death when it comes). I am getting a new little one tomorrow and will be holding my breath for the first couple of week, regardless of how well it "seems" to acclimate. I prefer not to get octopuses from an LSF because they so often try feeding fish (almost guaranteed to have been copper treated) but even a few of the octopuses I get directly from the collectors have died for no obvious reason (inking during shipping is an exclusion, that one we know, fortunately it is rare) and I would not discount stress as the culprit.
 
Well it is slightly better to hear that it is somewhat common for new, young animals to pass so early.
This critter that I had came straight from the ocean. Someone found him and then brought him in that day to see if he could out the octo in his tank. He let me take the octo, which I kept in the gatorade bottle he came in with an aerator. So this octo didn't have any fish from the store in it's diet, I made sure of that. Instead I fed him ghost shrimp.
 
I wish we knew more about the young deaths as it is likely avoidable we just don't know the key. With the few tank raised/bred we have journaled, if they survive the first two months they seem to live the expected lifespan. The highest mortality is in the first two weeks (much smaller than this one) but breathing easy is roughly at the two month mark. It may be that this one was easily caught because it was not going to make it even if left in the wild. Strictly conjecture but I don't have a better suggestion.
 

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