Dear Christos:

Only from these pictures (are too dark) is very difficult to answer your question. On the other hand, would be good to include in the figures a milimetric scale....

Hi Josep!

Thanks for answering. I will soon come up with brighter photos and the mm scale as well.

Hi Christos, can you provide some information on the the locality/finding place.

Best regards, Otto

I add some brighter photos, with the mm scale.. This is a commonly occurring snail in Northern Greece (river Gallikos - Central Macedonia - Greece). I hope this helps..

Hi Christos,

now, having received all the inormation from you I can fully understand your big questionmark. I consulted some friends and they also could not decide if this snail is a "Bithyniidae" or "Hydrobiidae". One of my friends (Alexander Reischütz) made a suggestion. He and his father (Peter L. Reischütz), a famous malakologist in Austria make a sampling trip to Greece and will also cross River Gallikos (in about 10 to 14 days). He suggested that if you like please feel free to contact Alex, he is also RG member and willing to sample at the river to have some living specimens.

with my best regards, Otto

ok Otto! Thank you! I will contact Alex..

Christos, resembles Peseudamnicola conovula (Frauenfeld, 1863). You can see a beautiful picture at the following website

http://3.bp.blogspot.com/-njrj_DPZs3U/U5xo4gEHhSI/AAAAAAAAEds/-r59BziXEUs/s1600/Pseudamnicola+conovula.jpg

Thank you all for answering.

I recently read a Greek article on Hydrobiidae of GREECE and it seems indeed like Pseudamnicola sp.. I attach the relevant link.

Thank you again

http://zookeys.pensoft.net/articles.php?id=3508