Dear Abilio,

when you Google

"picture atlas of marine invertebrates"

you get very useful material for use in your search.

Best wishes, Kees

Dear Stigter,

Thanks for your tip.

Hi Anita,

It has many spines in the surface and a straight digestive blind  tube. Also, in the anterior end it has some kind of tentaculate crown. 

Abilio:

Please put scale.

Best

Syed

Hi,

some measurements will be very helpful

Well, the organisms were retained in a 0.5 mm mesh.

In my opinion it is not an entire organism it could be a structure like an elitra or a vegetal structure, where it was collected

Dear Adriana,

It was collected 100 m depth in the Atlantic shelf.  

I'm assuming it was found in fine sediment from collection depth. Is that so, and perhaps fine mud? Also, does it appear ( as it may to me ) to have been attached to something?

Hi Tom,

The specimens were sorted from fine  carbonate sediment samples. There are many individuals that were not attached to any structure in moment of sorting. Thanks.

Look kind of like a flat worm. Platyhelminthes

I suppose it may be a fragment of some organizm like some fragment of gills or so

Viktor is right. These aren't typically marine, it probably was washed out with a river or something.

Dear Viktor and Gunnar,

The specimens were collected faraway from the coast al zone where there is no influence of freshwater discharge..

Dear Abilio,

Could be a cephalohordata larvae?? Me desculpe se estiver muito errada...estou estudando os Pikaia do Cambriano e ando um pouco empolgada!!! Abs.

Dear Maria Helena,

Thanks for your tip. I did not ever saw a cephalochordata larvae. Did you have any picture of it? Sua empolgação é muito boa. Tenho esse esqueleto (o bicho!) no meu armário há alguns anos e preciso dar uma solução. Abraço

Oi Abílio, não tenho foto não. Minha sugestão é baseada em: Se o animal foi fotografado em vista dorsal, o que se parece com o trato intestinal poderia ser a notocorda, mas aí teria de se investigar se há musculatura em V (os miômeros), pois não vejo essa evidência através do tegumento. Outra hipótese é que, se for o trato digestório (vista ventral), parece estar completo (descartaria ser uma planária por enquanto). A boca circular com cílios próximos sugere sucção ciliar, mas tá difícil mesmo, pela foto o animal está "achatado"...se ele for assim mesmo (achatado), minha empolgação para aqui. Mas estou curiosíssima tb!! Boa sorte e continuo a te seguir nessa investigação. Abs.

Oi Maria Helena,

Sim, o animal é achatado e tão fino que não faz diferença se visto dorsalmente ou ventralmente. Não tem miômeros. Tirei tb uma fotomicrografias eletrônicas. Se desejar ver, por favor, me escreva por email ([email protected]) que envio. Apreciaria se desse uma olhadela. Abç

Some kind of trematode DIgenea. To have something more detailed than this you have to go to an expert in the group.

Thank you Antonio Carlos. Is there any free-living trematode?

Oi Abílio,

Above in another reply you mentioned this has no myomers. If there is no muscle, then this cannot be a trematode or flatworm. You also mentioned a tentaculate crown at one end. Perhaps I am missing it, but I do not see that structure in the photograph. Might you have a different photograph to post showing the crown?

Hi Tom,

Take a look in the picture attached.

Hi Abílio,

As unlikely that this could have been collected so far offshore, I think Viktor's suggestion is the best. I have attached a page with figure 109 for you to compare with. How these found their way to your sample site, one can only imagine.

Hi Tom,

I do nor believe it´s not a marine animal because it was collected very far from the coast or from any river mouth at 100 m depth. Another reason is that since there are many of them, the probablity of be an animal transported from the land is very small on my opinion. Regards,

Details of the surface of the non-Id organism.

A closer view.