Unknown Phylum. Any suggestions?

30-40 cm is one BIG sea slug... I have seen big Aplysias before but usually around 25-30 cm. I have never seen the big ones swim before, only the little ones (about 10 cm or so). While the patterning looks the same, the body with the siphon, holes, eyes, whatever does not remind me of a sea slug...
 
Tremoctopus

Hi All

I have had contact with the South African Museum about the same pictures and I am pretty sure it is Tremoctopus. See attached picture. In the South African pics the arms are pulled in, which is confusing. However, the rest of the photographs resemble the attached pic I would say.

Regards Henk-Jan
 

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I dunno, the protruding snozzle thing doesn't really sit with Tremoctopus as far as I can see, although yes the colouring is similar.

"very distinctive ‘nose’/ trunk like protrusion which appears to be able to move independently of the rest of the body".

It looks very sluggy to me, but I'm a landlocked landlubber so what do I know?
 
It's a shucked ammonite.:wink:

At the moment, big swimming sea hare leads the non-ceph race, IMO. But, I gotta tell ya, my first thought was ceph. My after-a-glance thoughts were that it looked like some kind of finned cephalopod floating inverted, possibly with air trapped in the mantle, and that the twin pits on the top might be pouches for filamental tentacles...arms contracted or bitten off...etc.

But it also looks like a big swimming sea hare. As for the nudibranch theory, the head-on shot of the shnozzle thing reminds me of the business end of pelagic nudibranch.

AWESOME pictures. What a weird thing.

Cheers,
Clem
 
Torn. Colour and "zebra" pattern shout Tremoctopus!!! as loudly as Steve will at Greg during TonMoCon, yet the dimensions are just "wrong" and there needs to be a lot of allowance for arms being tucked away, etc. There seems to be fins ("winglets") on the sides of the creature that have something to do with sea hares, and holes where gills should have been, were this to be a nudibranch, that are in the wrong place for T. violaceus...

Edit: Winglets appear to be mantle opening, openings are in the right place on second thought,..., it's the trunklike thingamabob that bothers me...
 
Torn between two species, but as far as I'm concerned the most likely candidate is Tremoctopus violaceus, especially because of lateral mantle openings and pores on top, see 1st pic for comparison. Included as 2nd pic a ventral view with "zebra" striping obvious on webbing and the exact same orange colour as seen in the SA picture posted seperately by Steve at the start of this thread.

I would also not be surprised if the "trunk" appears to be angled because of simple diffraction and it is merely a pointy mantle. The 3rd pic is attached as an indication of "pointiness" in this species.
 
I am a novice when it comes to marine biology, but I do have an interest and I think cephalopods are cool. Looking at this post I am fairly convinced that the mystery creature is tremoctopus. Here are some visual comparisons of the photos already presented on this post that helped me with this conclusion:

Swimming style of Sea Hares:

swimmingbehaviorseahairsq9.jpg


They seem to have a very typical body shape and swimming behavior that does not look similar to the mystery photos. The mystery animal seems to lack the large, skirt/wing like appendages. Also, the sea hares seem to keep elongated for the most part with thinner structures both forward and behind the animal, features also apparently not present in the mystery animal.

Also notice the color patterns, they are very mottled and there is rarely a smooth coloration even on a portion of the sea hares, unlike the smoothly colored animal in question.

The portion of the sea hare that is mantle like in appearance, as far as I know, lacks the holes visible in the mystery animal.

More Texture and Morphological Differences from Mystery Animal and Sea Hares:

seaharetextureshl2.jpg


The stalk like appendages do not appear in the mystery photos as far as one can see. The animal could be inverted.

Similarities Between Tremoctopus and Mystery Animal:

tremoctocomparisonls0.jpg


Notice that the mystery animal, when alligned with a top view of tremocto, has a similar proportionality in features. This could be flawed to some degree in the comparison due to different perspectives in the photos and the size of the animal in each is unkown. However, the two holes are present in both, coloration is smooth and similar, and other parts of the mantle seem to be a match for the mystery animal. Swimming behavior of both also seems alike.

The big difference is the lack of tentacles in the mystery animal. It seems to me that they could be tucked-in in the mystery photo. Using Occam's Razor, it seems easier to me that this would be something similar to tremocto with tucked or missing tentacles instead of a sea hare that has lost its wings, is swimming oddly, has tucked or lost other anatomical features, and has a rare coloration.

As for nudibranchs, the branching structures seem to be absent in the mystery animal, and again, coloration and wing structures are also not visible.

This is the weakness of relying soley on photos. You cannot always get a descriptive angle and the animal may not be in a typical pose, meaning one can draw many conlcusions and imagine just about anything:smile: Goodluck, I really look forward to the verdict!
 
Well, as we were basically posting a similar post at the exact same time, I guess you can count me in, positively :wink:
 
Certainly OB:smile: I did not mean to repeat your post. I only saw your first pic when I grabbed it. Your second picture clearly shows that tremocto can have the striping visible in the mystery animal, one of the things that had not been posted previously. Good job!:smile:

Could the octopus be feeding on something, if that is what it is? I am not familiar with why an octopus would swim with tentacles tucked in other than for mimicry, which I have not seen performed at the surface. Illness, as stated previously, is also a good reason for why an animal might behave funky:smile:
 
When the female T. violaceus swims, she usually tucks in both ventral pairs 3 and 4 and leaves pair 1 (short, with large webbing attached) trailing and pair 2 (long) in support of the webbing, but I wouldn't know why there couldn't be different modes of swimming out there. Pair 2 can be quite contracted and stiff, almost like a hoop, or relaxed and extented, I guess it's merely a case of the former with this lady here.

Your comparison of the the swimming specimens just below the surface shows the earlier positive ID to be of even more pointy mantleshape than the SA one.
 

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