ID of Pond Beastie

[lucysboss]

Hi, I'm a new member & need help (in many ways) Pond dipping with school group so no pic I'm afraid. Beastie was about 5cm long, translucent creamy/white. No obvious head, just pointed at each end. A black line down centre of body presumably the gut. It moved like a "slinky" spring by drawing up the back? and pushing forward the front The body contained what looked like a slug of mercury (silver coloured) which moved forward internally to give the impetus to move the front half. Any ideas anyone? Thanks in anticipation.

[slimrbp]

Hi, welcome to WAB.

The description of the movement puts me in mind of a Leech, but hopefully the more knowledgable members will be a long soon

[Deb London]

Big transparent leech

Unknown leech - might be of interest.

[RoyW]

Sounds like a good description of a leech (the species we have in Britain aren't likely to attack humans though).
The silver coloured slug you descibe is probably the internal organs/gut contents. Forward movement would be by 'normal' muscle contractions, the internal parts just move backwards & forwards as a result.

The kids you were pond dipping with would probably have loved to have been told that they'd caught a leech!

[healfdan]

A very common leech found in ponds and slow moving rivers is Helobdella stagnalis. Fits your description although not too sure about the black line along the back. Still worth checking out even if only to discount it.
Healfdan