Jump to content
mattdiver

Slimy thing

Recommended Posts

Hi Guys,

 

I recently saw this slimy thing slithering on the sand in Indonesia.

 

It may well be something common, but I've never come accross anything like it before, and I can't find it in books.

 

Description in short: about 1m long, 2cm wide, and 3-4mm thick.

 

The second photo shows what should be the head (?), from which it was probing and moving ahead.

 

Anyone knows what this is?

 

Thanks,

Mat

 

post-4904-1127017092_thumb.jpg

 

post-4904-1127017112_thumb.jpg

Share this post


Link to post
Share on other sites

It's a sea cucumber. Phylum Echinodermata, Class Holothuroidea, maybe Euapta godfreyi or one of the Synapta species. It feeds by probing the sand with its sticky oral tentacles for tasty bits then inserting the food-laden tentacle into its mouth -- sort of like a kid licking his fingers.

Share this post


Link to post
Share on other sites

Don't laugh too fast - they're popular food items in many parts of the world!

 

Joe - I kept thinking I knew you but couldn't remember why. Today the brain cells kicked in: didn't we both work at MBC in the mid-80s? I was in the tax lab, & you were a field tech?

Share this post


Link to post
Share on other sites

Hi guys

 

I am not sure that this is a sea cucumber !

 

there are some "slimy" ones - synaptids for example, but they are not that flat ! 3-4 mm ..

 

I would say it's a nemertean worm, I know some are very long (exceed 1 m)

 

but maybe I am wrong ..

 

cheerio

 

Art

 

:)

Share this post


Link to post
Share on other sites

I thought about that possibility but decided against it as this animal is translucent (you can see right through it). I've never seen a nemertean that wasn't completely opaque. Still, I'll send it to Jon or Megan and see what they think. If it's a nemertean they'll recognize at first glance.

Share this post


Link to post
Share on other sites

Leslie

 

some nemerteans are pelagic !!! have some references (but see also Brusca & Brusca)

 

so why not a semitransparent benthic one ?

 

but we'll see .. on the other side, I don't know of any really flattened holothurians either

 

Art

 

:)

Share this post


Link to post
Share on other sites

I know, I use to work on them. I'm willing to be convinced and equally willing to admit I'm wrong! :)

Share this post


Link to post
Share on other sites
I know, I use to work on them.  I'm willing to be convinced and equally willing to admit I'm wrong!  :)

 

And I am wrong. It's a nemertean. Good thing you're around to keep me in line! :)

Share this post


Link to post
Share on other sites

Well, since I'm trolling through here looking for nemerteans... ;)

 

My first hope was nemertean, but dashed that hope the instant I saw it was translucent. Sorry, no translucent benthic nemerteans. They have way to much muscle tissue (almost lacking in pelagic nemerteans). Synaptids are commonly translucent. I don't know anything about tropical ones but would bet dollars to donuts that Leslie is right on the money.

--Jon

Share this post


Link to post
Share on other sites

I was right originally? With that head?

Share this post


Link to post
Share on other sites

I'm glad that this photo prompted so much interest, didn't expect it...

 

Since we're at it, after Leslie's first reply, I felt a bit curious. Being no expert in sea cucumber or marine biology, I'd always thought that sea cucumbers were members of the echinoderms, and had a penta-symmetry. So a flat sea cucumber sounded unusual. But then again, my knowledge on this is very limited...

 

Any clarification, even succinct, would be appreciated.

Thanks,

Mathieu

Share this post


Link to post
Share on other sites

You're right about the penta (5-sided) symmetry. That doesn't have anything to do with diameter or shape however. Some sea cucumbers have fairly rigid exteriors & appear round or rounded on top & flat on bottom. Others are very soft & quickly go from a circle in cross section to completely flat by expelling their internal water.

Share this post


Link to post
Share on other sites

OIC. Thanks for the explanation. Guess I'll have to get myself one more book on marine life and get more dives in to observe critters :)

Share this post


Link to post
Share on other sites

More diving is always a good option!

Share this post


Link to post
Share on other sites

Leslie's uncertainty has me wondering. It definitely is not a nemertean. There are not many translucent options among benthic critters, especially at 1 m long. It's not a benthic ctenophore and I am almost certain there are no marine flatworms this long. We may be looking at the hind end of whatever it is. If we are seeing sediment in the gut, it almost has to be a synaptid; they certainly get that long. If we are seeing sediment through the entire thing, I would guess that we are looking through the tentacle of the world's biggest terebellid polychaete, which would tally with the probing behavior. A scary thought. Leslie, could there be such a large terebellid? Or maybe the hind of one?

Share this post


Link to post
Share on other sites

Certainly not a polychaete tentacle! And I don't know of any terebellids that come out of their tubes. Maybe the world's largest echiuroid proboscis?

 

Matt - you're just going to have to keep diving until you find & rephotograph this thing for us. Now get back in the water!! :)

Share this post


Link to post
Share on other sites

Actually, I do have a couple more pictures of that critter, whatever it may be!

 

I'm not sure whether they provide more insight on what it is, though... <_<

 

post-4904-1130157239_thumb.jpg

Share this post


Link to post
Share on other sites

This shot's horrible artistically speaking, but gives an idea of its length...

 

post-4904-1130157294_thumb.jpg

Share this post


Link to post
Share on other sites

Actually, while skimming through my pictures, I uncovered a shot of this thing, taken during the same dive:

 

post-4904-1130157374_thumb.jpg

 

Hope this one's easier to pinpoint :)

 

Mat

Share this post


Link to post
Share on other sites

Now this one's really interesting as it might be a polychaete in the family Flabelligeridae.....maybe..... it could also be a weird sponge or cnidarian but the regularity of the side appendages really suggest a polychaete. Can you send me a high res file ? I need to see more detail.

 

You have quite an eye for the odd ones!

Share this post


Link to post
Share on other sites

Thanks for the file. I am much more confident now in calling it a flabelligerid polychaete, possibly in the genus Flabelligera or Flabelliderma.

Share this post


Link to post
Share on other sites

mmmmm, compare with this not very good picture of Lomanotus vermiformis (a nudibranch at Bocas del Toro, Panama) but I can see the potential for difficulty;) I know this only because I sometimes take bad pictures of things other than nemerteans - especially when Leslie isn't on-site to make me feel too self-conscious about it:)

--Jon

 

post-5293-1130528446_thumb.jpg

Share this post


Link to post
Share on other sites

Worm girl, if you deside that Jon's right and you're wrong about this one being a worm, you may want to abuse your moderator powers and delete this whole thread to keep up the appearance that you know what you are talking about. :blink:

Share this post


Link to post
Share on other sites

Sponsors

Advertisements



×
×
  • Create New...