Can you please help? Last week (Sept 2013) I saw a very strange creature 'swimming' on the surface by the dockside in Skopelos harbour (Greece). It looked like a sort of sea cucumber, but it had 'wings' which it undulated in a flowing action to move slowly. The body was about 8 inches long and about an inch and a half in diameter - like a longish sausage. The 'wings' stretched right along both sides of its body, they were semicircular, widest in the middle and tapering back into the body at both ends. The 'wings' extended about 2-3 inches from the body at their widest point. The animal was coloured, but didn't change colour as I watched, it was marked rather like a pinto pony, large patches of white and a dark brown (that could have been dark maroon). It clearly had mouth parts at the front, for it kept gulping air on the surface. It's mouth resembled that of a tiny manatee, in that it split open - like a split top lip. Other people joined us and we watched it for about 15 minutes, it never left the surface, moving slowly, constantly, in a very primitive fashion by rippling its 'wings'. It appeared to take no notice of us. I saw no eyes on its body. There were small fish in the immediate area which took no notice of it.
I've never seen anything like it - can anybody identify this animal?