After so many years... still no ID

[I-NSC 1]

It is not a nudibranch as it does not have any gills or rhinophores nor is it an underwater banana. It does crawl and is about 5mm in length. The head is on the left while the body is almost circular instead of flat.

Shot in Mataking, Sabah, Malaysia in the day, at the depth of 12m.

 

What could it be? I have initially asked around and one results I received was a juvenile sea cucumber. Can anyone verify and confirm? Appreciate your viewing and comments.

 

Edited November 12, 2012 by I-NSC

[JimSwims 31]

We have a sand dwelling holothurian down here that has similar shape and smooth texture. Paracudina australis, maybe something in Caudinidae???

http://museumvictoria.com.au/pages/31323/68_oloughlin_barmos_vandenspiegel.pdf

 

Cheers,

Jim.

[I-NSC 1]

We have a sand dwelling holothurian down here that has similar shape and smooth texture. Paracudina australis, maybe something in Caudinidae???

http://museumvictori...ndenspiegel.pdf

 

Cheers,

Jim.

 

Interesting... thanks Jim. Will have to read up on the papers.

[Leslie 0]

Do you have other photos of it that you can post? Or perhaps a enlarged crop?

[I-NSC 1]

Do you have other photos of it that you can post? Or perhaps a enlarged crop?

 

Dear Leslie,

 

I am afraid that I do not have any other images of the subject as I lost most of the images when my HDD crashed.

[Leslie 0]

Too bad about your HDD!

 

Well, I don't think it's a Paracaudina or another sea cucumber. Paracaudina species - especially young individuals - have translucent skin and it's easy to see the 5 muscle bands characteristic of holothuroids. They should be visible in an animal this size. I believe it's probably an acoel worm. They aren't noticed very much because of their small size. Until recently they were classified with flatworms but now they have their own phylum - Acoelomorpha.

[I-NSC 1]

Too bad about your HDD!

 

Well, I don't think it's a Paracaudina or another sea cucumber. Paracaudina species - especially young individuals - have translucent skin and it's easy to see the 5 muscle bands characteristic of holothuroids. They should be visible in an animal this size. I believe it's probably an acoel worm. They aren't noticed very much because of their small size. Until recently they were classified with flatworms but now they have their own phylum - Acoelomorpha.

 

Thank you Leslie,

 

I will look into the acoel worms to see if there are any other similarities and information. It is interesting to know that it is something not too observed due to it's size but when your waiting for a videographer dive buddy and looking around at a single spot, you tend to notice the smallest of things moving on the ground.