Surprise! It's a Mimic!

[davelin315]

I have had a number of peppermint shrimp do just fine in octo tanks BUT the oddity is, no matter how many I have put in, ONLY one survives and the others are eaten. I am not sure if they kill each other and then the octo eats them or one gets an assigned territory too close to the octopus.

The one in the video practically crawled across her. She has two in there that I added and they are actually looking quite pretty in there - they are turning really red and I know that at least one has eggs so we'll see if they do any better in a system without anything that eats them!

Seriously, though, it seems really odd to me that she shows no interest unless she recognizes them as cleaners, although I'm not sure that I've ever seen anything on octopuses visiting cleaning stations. She has eaten Nassarius, Astrea, Ninja Star Astrea, Trochus, Cerith, and Nerite snails now but still not a shrimp? Hermit crabs, fiddler crabs, emerald crabs, but again, puzzled by this lack of interest in shrimp. If this keeps up perhaps I'll add a coral banded shrimp to take care of some of the bristle worms. She grabbed 2 or 3 crabs again tonight despite not being all that hungry. She didn't really pay them much attention (she had 4-6 crabs last night as well as a snail) until one decided her arm looked like a nice meal or a pinching post. She then grabbed it, bit it, and then grabbed another one and held it until she was done killing off the first crab before taking care of it as well.

On a cool note, sorry, no photos yet, her arm that came in injured continues to grow and the arm that had the tip bitten off by the molly has begun to grow back.

 

[davelin315]

I have taken to feeding her 4 crabs at a time and tonight was one of the cooler feedings as I saw her doing a behavior I had witnessed only sporadically and wasn't sure that it was an actual behavior or just from her touching the aquarium wall as she moved about. Anyway, she was "tenting" and standing up on her arms almost like an "octopod" (ha ha, play on tripod despite it actually being correct). I have seen this behavior before but tonight she was actively doing this across the rock and I saw her picking up shells so I take it as a hunting behavior. I wasn't able to capture this on video but when I fed her she "tented" again and when I fed her she stayed propped up against the glass. I was able video from a low angle as she moved one crab she grabbed into position to bite it and then moved the other into position to bite it as well before settling down for her meal. It only takes about 15 seconds or so to start immobilizing each crab but she definitely waited for a few minutes before starting to eat. I will post video when it is downloaded, again, about 15 minutes of video capture which is huge in size.

 

[davelin315]

9 new photos by davelin315

photos.app.goo.gl

 

[davelin315]

Tonight's feeding was a bit different than the normal ones as I decided to see how many crabs she could handle at once. Turns out she is limited by how many arms she can dedicate to each crab without getting pinched. Check it out. So many crabs, not enough arms...

Interestingly when she abandoned one of the immobilized crabs (aka dead) I examined it and did not find any evidence puncture or bite wounds. Looks like as she is enveloping the crab she is not injecting the toxins but perhaps spraying them. She did take the crab she dropped when I offered it to her afterwards so no wasted crabs tonight.

 

[davelin315]

No interest in peppermint shrimp still.

In this one she yet again shows that she has zero interest in eating a peppermint shrimp. They never touch her but they certainly go very near her and she shows zero reaction. I wonder if perhaps she recognizes them as a cleaner species? I would doubt it as I have never heard of octopuses visiting cleaning stations in the wild or in captivity but I suppose anything is possible.

By the way, she also much prefers fiddler crabs to emerald crabs as you can see from the video.

 

[davelin315]

And finally, some photos taken while she was eating, post getting pinched.

 

[DWhatley]

I break the tip off the male fiddler top claw before feeding. The fiddler often throws the claw if I am not quick enough but breaking the tip keeps me and the octo from getting pinched enough to make a hole.

Judging from the pulled "flap" on the crab she runs off with, maybe she is not injecting venom but simply using her suckers to kill the crab by separating the shell. Even the female crab you examined with the skewer after she has killed it appears to have had the "flap" pulled.

 

[davelin315]

I break the tip off the male fiddler top claw before feeding. The fiddler often throws the claw if I am not quick enough but breaking the tip keeps me and the octo from getting pinched enough to make a hole.

Judging from the pulled "flap" on the crab she runs off with, maybe she is not injecting venom but simply using her suckers to kill the crab by separating the shell. Even the female crab you examined with the skewer after she has killed it appears to have had the "flap" pulled.

I have done that in the past as well but tend to leave them alone now in terms of the pincer. I figure it is enrichment making sure to eat carefully.

That very well could be the case with how she is killing them, I have been contemplating figuring out how to film from below to see what is happening under her mantle... those little convulsions as she kills the crab could very well be the act of pulling the shell apart.

 

[davelin315]

She is still going strong and I observed a new "color" pattern on her tonight but was not quick enough/willing to stick my crabby hand into my pocket to grab my phone to get it. Tonight when she went after her first crab she turned completely black, no stripes, nothing. It was pretty stark going from the beige color to full black but after grabbing her first crab she went back to the dark color with some patterning on her in the beige color. Will try to get a photo of it tomorrow night when I next feed her.

 

[pkilian]

Those are great photos you posted. Really nice coloration!