Anyway, my search has been horror. I went to every toy shop in town, visited the thrift shop every other day and I digged in the toyboxes of my niece and nephew to find what I was looking for but it just doesn't seem to exist.

We went to the fish material shop yesterday and I bought these 2 below but I'm not really thrilled about them. The tail of the first one is too long and the tail of the second one is not really a tail, it's a flat piece so that fisherman can add it to their hook. I might use the head in this case.
So I'm goingto experiment with those two for now.
If you have any fish laying about that you would like to get rid off for art purposes, don't hesitate to contact me. I'll be happy to hear from you: mitsy@artmind.eu
Just don't send me anything yet, but show me a picture first so that I can see if it's useable and if it's THE fish I have been looking for. I'll pay for the fish and shipping or if you like an exchange better, we'll trade a fish for a singing bird! :)