Yeti - O. briareus

[DWhatley]

The pictures look more briareus than in person. His eye stalks are more distinct and raised than I think they should be and, even though he has doubled in size, I keep thinking he is growing slowly in girth. I think I am just imagining it but when I look at him I can't help but wonder if he will be really really small or is something else.

[DWhatley]

I took a chance with the flash after giving him a rather large (comparatively speaking) piece of crab (shell on) tonight. Unfortunately, The camera could not focus well into the abyss and even with help from my editor the clarity is poor. His colors are certainly briareus but I don't know if others can be similar. Every picture I have (not many) taken with flash of Cassy or Tank show the luminescent green speckles they are known for, none show arm stripes and the eyes are closer to the head and the head and mantle are more robust (the main things that have me wondering). The only other animal that I think Yeti could be is the Atlantic Longarm octopus, Macrotritopus defilippi.

[DWhatley]

I'm probably going to regret (or at least be embarrassed) posting this but I am sticking my neck out and saying I don't think Yeti is O. briareus. His mantle always looks quite pear shaped and his arms are most fragile looking. Tonight I invited him to touch my finger and he reached out and pulled a little. He is not very strong and this seems to go with the fragile look. He IS very curious and climbed in, out and through his live rock to examine my offered finger. I am relatively sure he is a young octo and not an unknown dwarf. All the dwarfs I have seen have a much more robust mantle, his is very slim.

We tried offering shell on shrimp last night. He striped the shell off the shrimp in one piece while it was on the feeding stick but did not remove the shrimp. I could feel vibrations in the stick like he was biting it but there was no exposed stick under his webbing. He decided it was not worth messing with but did not run away or even blow it away when I tucked it under his webbing, he just refused to take the food. I swapped it for a piece of crab and saw him very tentatively touch his suckers to the meat part to test it before he decided it was edible I still think that table shrimp may be too tough for the young ones even though this was a section near the tail that should have been tender.

[DWhatley]

Yeti appears to use his arm as a fishing lure like an angler fish or is looking for microscopic food in the water column. I tried to video the behavior with little success. I did post a clip on YouTube but the upload changes make the action even more difficult to see. I have noticed O. mercatoris appearing to skim the water for food and LittleBit would turn upside down at the surface (presumably eating Cyclop-eze) but this is a different approach and looks like he is using his arms to attract live food. Tonight I used a flash and you can see the arm but the still does not really depict this unusual behavior.

I am convinced he is not O. briareus but am not at all comfortable with naming another species. I wonder if the apparent feeding behavior is related to having been a small egg animal but I have never seen it in others. Also of note, he seems to totally avoid the sand. His supper fell off the feeding stick and he zoomed down a level on the rock but would not go out onto the sand or even reach for the piece of crab. When reoffered, he refused it emphatically and I had to get a new offering before he would eat.

[DWhatley]

Not much of a picture but significant! This is the first we have seen of Yeti during daylight (early evening) hours. He was not out long but I was able to give him a shore shrimp so we will not feed him at his normal 11:00 PM time tonight with hopes of being able to feed with the rest of the tanks around 7:00 PM.



I am still not at all sure on species but have relabeled him defilippi (Atlantic Long Arm) until I can come up with something negating the ID or find a better match. Of the videos I have seen, he reminds me of Ameloctopus litoralis but that species is smaller, not found in the Caribbean, has lower set eyes and has no ink sack. However, if you watch this video , Yeti's movements and general look are the same. Note how Ameloctopus molds to the substrate. One of the words Hanlon used to describe the one he kept was delicate and that well describes this little guy in there is not much to him. His arms are long but thin and his grip is not very strong. He was definitely a baby when he arrived and has at least doubled in size but I don't expect him to be as large as the smaller O. briareus and definitely not as thick in arm or mantle.

[CaptFish]

Yup, I'm petty sure NickNack and Yeti are the same species, they look identical. I like the Defilippi guess, and agree.

[DWhatley]

Friday Yeti showed up as Neal was feeding the tank and slithered (only way to describe it) around on the far side (furthest from his den) to pick up pieces of shrimp from the substrate. When offered the same shrimp on a feeding stick he has totally refused to eat it. I have mentioned that I wonder if it is too tough to eat when they are small but something else crossed my mind when I watched the savaging behavior. His approach to retrieving the food was very much like that of the "Pesky" (red brittle stars are all named Pesky in our aquariums) that lives with him. Pesky's are often found in our octopuses dens but this observation was at the far side of the tank and Yeti and Pesky were together. This is particularly interesting in light of the suggestion that he may be the "Atlantic Mimic" and unproven suggestions that octos can learn from observation (non-repeatable study with conspecifics made the news some time ago. Additional observation suggests observational learning still may be a possibility in spite of the discounting of the original study)

Second daylight spotting at about 5:00 PM on Saturday (more than an hour before normal feeding time). Yeti was out at his normal 11:00 PM feeding time Friday night (after his scavaging and being given supper) but I did not offer food so when he showed up at 5:00 PM I gave him a crab even though it was early. Unlike previous delays and missed first attempts, he was so fast to "jump" off the rock, catch the crab and disappear with it into the live rock, I was not able to get the planned video .

However, I did get a couple of pictures before the food offering. Note the tiny white papillae. They looked much like the fish parasite commonly called ich ([I]Ichthyophthirius Multifilis [/I). These are distinctive raised papillae and not just white spots). Reviewing Roger Hanlon's most recent video on O. defilippi, I see a similar look on the mantle as the animal digs into the sand and then on the rest of the body (but not the mantle) when it exits.



The second photo I shot for size perspective but did not get a full shot of the tank so he looks larger than what I was trying to capture.

[corw314]

Hmmmm.....looks like Squid.....

[DWhatley]

Nope, I am 85% sure he is not O. briareus (and 100% sure squid IS). However, there are a lot of features that are similar and he could fool me yet. Behavior is way different for one and, in spite of my effort, the perspective shot just does not show what I was trying to capture. I need your photography skills!

[DWhatley]

It took Yeti awhile to come out tonight but he was in position (across the tank from his den) at feeding time. Even at this size, the feeding stick is something that needs to be captured and he battled the urchin for the right. Note Pesky is being pesky on the sidelines

[DWhatley]

Why tonight's topics had to be escapes and missing arms is beyond me but ... Yeti did not come out for his dinner at normal tank feeding time but he did have a somewhat larger piece of shrimp last night ... No sign at 11:00 PM ... Now I am nervous and uncomfortable with the behavior change and stop posting to go looking yet another time. This time I checked the overflow, nope. Sump? Yikes! and missing arms! Oddly his longest arms are still in one piece but I think all of the other six poked into places in the hardware that were unsafe. Most of the intakes have sponges just to keep out larger things that might end up there but the sump was never intended to be octo safe or octo inhabited.

I have been considering moving him to the 40 ish (I think I determined it was 37 gallons) that was LittleBit's home until she out grew it but he was doing well in the 65 and and moving him would have been difficult unless I moved him in his den. Since I had to fish him out of the sump, I decided to go ahead and move him to the smaller tank. He inked once during the fishing expedition but only because he touched my hand while I was trying to scoot him toward the cup (he climbed over my hand at one point and did not ink), being chased with a cup did not seem to bother him and he sauntered away rather than zipping off. He was afraid to exit the cup though and I decided to try to feed him but he refused the piece of crab that was his planned meal. I tried his second favorite food, fresh shore shrimp, which he decided to take and then exited the cup with his dinner. Hopefully he will settle down and unstress in the darkness.

I took a picture while I was acclimating him to the temperature in the new tank (about 2 degrees difference) in hopes that I could see the damaged arms but he keeps his arms tucked in a spigetti mishmash with not moving about and the photo does not give any hints. The only thing of note in the photo is the presence of fluorescent green spots that I noted as not having seen while trying to ID him.

[octo..]

My Macrotritopus has never turned green like this before

[DWhatley]

fluorescent green dots are typical of O. briareus but there are others as well so not in themselves diagnostic. Their absence would mean NOT briareus but presence does not confirm an ID. This is the first time I have seen them on Yeti (they are not always visible but commonly seen on briareus. A flash will usually expose them). The fluorescence is often used to spot briareus diving at night using a bright light. I don't know if they are present on Macrotritopus.

[corw314]

My son just walked in the room as I was enlarging Yeti and asked "Is that when you got Squid?" I chuckled....Yeti is so cute!!

[DWhatley]

LOL, he/she may still turn out to be O. briareus.

Yeti is extremely shy again since his misadventure to the sump and relocation to the smaller tank. He is eating well but not coming out at supper time and waiting for his food but when we locate him and put the feeding stick where he can touch it, the food is taken and appears to be consumed.

[DWhatley]

After 3 months it is clear Yeti is a dwarf and nocturnal. In spite still looking like a baby O. briareus, I THINK I may finally have an O. joubini. However, if this is O. joubini, I do not understand how a cephalopod specialist could have determined that there was only one common dwarf as it looks nothing like O. mercatoris.

[DWhatley]

Yeti is finally getting stronger and tonight was able to move the LR when he pulled on the stick . He/she still looks very much like an O. briareus and is still too small to be one. The one behavioral difference I see is his/her crazy arm waving. It often looks like one of the brittle stars hunting techniques and I wonder if it is natural instinct or learned from tank mates. We seem to be back to the pre-sump excursion boldness (finally) and the last two nights Yeti has come out to eat relatively early. Last night he popped out and watched us for awhile when we were sitting in the breakfast room talking.

[DWhatley]

I have reclassified Yeti as O. briareus. I am still not sure this is what she is and her arms (at least some of them, she does not show all of herself much yet) are VERY long for her mantle size but her mantle if very small yet.

Video of passing cloud display - she has not done this before. I had given her a crab when she popped out of her den early tonight but I think she was still hungry and was trying to get my attention. You can get a feel for how long at least one pair of arms are in the video, the length is not a faction of angle of the camera.

[DWhatley]

The video shows a bit of the odd style of hunting Yeti uses but it is not as strange as we see at night. Watching her, it reminds me of the way her "Pesky" hunts. There has been a brittle star in the tank (two in this one) since she arrived and I am wondering if it is a learned behavior.

[DWhatley]

I think this is the first video of fully out the den. We see her/him more and more frequently but only the mantle, eyes and whatever arm tips that come out of the LR. Last week he did reach for my finger that I was moving around outside the aquarium and realized how loooong the front arms were. I think the video leave little doubt that she is indeed O. briareus but I expect she will be much smaller than others I have kept.