Big transparent leech

[vole-woman]

Stream-dipping this evening in our local nature reserve, we pulled out what at first we thought was a blob of snail-egg jelly. Imagine our surprise when it began to squelch across the surface of the net, waving its tentacle at us. It was an amazing thing. Are these transparent leeches common?

[Dogghound]

It is likely this was a type of diptera larvae. Did you get a photo?

[vole-woman]

My son did. I'll upload it tomorrow.

[vole-woman]

Here it is. Not a great quality photo as it was taken with my son's camera, but it gives the general idea. I'd say the blob was abut the size of a penny piece.

[Dogghound]

Hm... very odd little creature. Yes a leech of some description.

[vole-woman]

I thought all leeches were black/brown.

[Dogghound]

So did I . Thats why I though straight away that it was some type of fly larvae. Ive never really looked closely at leaches.

[animartco]

I have seen a bright bottle green leech but never a transparent one. Fish leeches are semi-transparent but have definite stripes. Did it move like a leech? And could you see any internal structure? If it didn't move like a leech it might be some sort of melanin deficient tadpole? Is there a land drain running into the pond?
very interesting. Hope someone comes up with an ID

[Malcolm Banks]

I reckon it is a leech. I posted an olive green leech (image below) from my pond last year, and the nearest ID I managed was a duck leech (parasite of anatid waterfowl) - this I thought most improbable until I saw a pair of mallards on the pond at a later date. Stretching it a bit to call it translucent like VWs though, so probably no further forward with that one.
M

[Chiltern Ben]

Hi,

I think it's a leech called, Helobdella stagnalis. It's a common leech and can be found in many parts of the world - including British ponds. I've seen pictures of them as both whitish and nearly transparent forms.

Cheers, Ben