Hi

I recently read about Holothuria arguinensis colonizing the Mediterranean Sea, and Your specimen resembles that one - but I'm not sure on this. H. arguinensis has previously been Distributed in the Atlantic but probably due to human impact it is now beeing reported from the Mediterranean. It has also been confusions regarding calling it H. arguinensis or tubulosa.

I attach an article on the matter. Please keep in mind that the Holothuroidea may be difficult to identify, and for a certain id several Things should be checked including the ossicles. The article will give you an idea of the shape of the ossicles for this particular species.

Kind regards, Halldis Ringvold

Hello Egidio,

you specimen is definitively an aspidochirote sea cucumber, most likely a member of the Holothuriidae ... for better identifications we will need more views of your specimen (amount and shape of tentacles ... bivium = dorsal ... trivium = ventral) ... And I agree with Halldis, for detailed species dentification you have to look on the microscopic body wall ossicles too ...

Best wishes, 

Mike

Its holothuroid, but a detailed close up is reqd. to identify the species

Thank yoiu all. When I have found it I was not in the conditions to preserve it for a detailed study. I was impressed by the yellow spines in the flanks of the body that do not appear in any mediterranean species. Maybe in the next future I will have the opportunity to find more and to preserve them. 

Gosh, what a marvellous holothurian. I agree with others that it is an aspidochirotid perhaps referable to the genus Holothuria but this requires more observations and pictures of tentacles, calcareous ring and ossicles. Egidio, what you describe as spines are perhaps tubercles for the papillae or tube feet. I haven't seen such a beast before, at least not in a living state like when photographed.

Most likely Holothuria arguinensis

Now that I have looked at Gustav's comment and GonzalezBorrero's 2012 paper I think it may be H. arguinensis. Ossicle pictures will help. Recently Karim Mezali and I published a record and description of this species from Algiers Bay. It looks different from your & GonzalezBorrero's specimens and might be a variant. Sorry could not download paper bur you can view it here.

Marine Biodiversity Records, page 1 of 4. # Marine Biological Association of the United Kingdom, 2014

doi:10.1017/S1755267214000438; Vol. 7; e40; 2014 Published online

Hi Egidio

The very first impression of the documented specimen suggests Holothuria arguinensis.