Diptera.info

Posted by cthirion on 29-04-2010 23:22

Unknown

Fixed on sediments

2cm, B/ Lac de la Plate Taille, barrage Eau d'Heure

P.Bouxin photo

Edited by cthirion on 30-04-2010 10:41

Posted by Tony Irwin on 29-04-2010 23:32

photo??

Posted by cthirion on 30-04-2010 15:37

I asked Tony to insert the photograph but it misses, I asked Paul, that then does not pass from at home!
A little patience!
Camille

Posted by Paul Beuk on 30-04-2010 17:23

No wonder it did not attach: illegal characters in the filename and a whole bunch of spaces!

Posted by cthirion on 30-04-2010 19:33

Thanks Paul!
Camille

Posted by atylotus on 01-05-2010 10:05

The locality (lac/lake) suggests that you have photographed it in aquatic or at least a wet habitat. The white part with the black spots, reminds me of a snail of the genus Radix. But if this is true, the snail is already dead or dying and not within the shell. The yelly, striped part looks more like a Hydrozoa. This means, that I don't know for sure. Will you let me know if it could be aquatic?

Posted by cthirion on 02-05-2010 22:29

Yes, it was posed on fixed sediments, was observed in diving! Several between 6 and 20 m of depth, resemble a mussel without shell.

Thanks!
Camille

Edited by cthirion on 02-05-2010 22:31

Posted by cthirion on 05-05-2010 15:40

Nobody to specify, please?

Posted by atylotus on 05-05-2010 18:41

There are no freshwater bivalves with these kind op pigmentspots. I have seen this only in the genus Radix, a freshwater gastropod. You can see the pigmentspots on the mantle of the body at the leftside of your specimen. At the top it seems as if you photographed the actual head, which is entirely white. At the right hand side you'll notice the brown remains of the posterior body with undigested material in the intestine. The posterior body is retracted within the (missing) shell and is softer than the anterior part with the head, which is more or less outside the shell (when living). I'm not sure which Radix species it is for the shell is missing and I'm not quit sure if it is actually the head at the top. If the head is unpigmented, then it must be Radix balthica, if the head has small blackish pigmentspots then it is R. auricularia. The edge of the mantle (which is the thick line between the pigmentspots on the mantle and the jelly part at the lower part of the photo) is unpigmented as well as the head (?) so Radix balthica is most likely. In R. auricularia the edge of the mantle has a row of multiple blackish spots. I have no idea what this jelly striped material is at the bottom.

Posted by cthirion on 06-05-2010 15:36

#10

Thank you from P.Bouxin and C.Thirion!

Posted by Tony Irwin on 12-05-2010 11:38

#11

It looks like a bird dropping to me!