Do they contribute to the healthiness of the pond?
I seem to have loads in mine.
They don't seem to be harming the fish, it's just that I don't like them attaching themselves to me when I clean out the pond.
Can they be got rid of easily?
Are you sure they're leaches? There is a little veggie thing that looks a bit like one... Or so I was told once.
I think!
Ollie, you might be thinking of lampreys? But they live in rivers, not ponds.
Sorry, have no idea what you can do about leeches. Yccchhhhhh!!!
ewww, yuck! (having done a bit of googling)... no, not them... crikey! Monsters!
On phone to dad in a mo so will ask him. I had them in one of my food "ponds" as a kid (bins for growing food for my tropical fish)...
I'm thinking of Planarians and I'm wrong... they wouldn't grip to you apparently! I'd love leeches, aren't they quite rare?
You get a number of different leeches in ponds - the most common being Erpobdella sp (liver coloured and longish) and Glossiphonia sp (light green colour with darker dots on the back - also broad) these both feed on snails or invertebrates so not a risk to your fish.
Another type Pisicola sp (which if I remember are light green coloured but long with very noticeable sucker bits)do predate on fish. If you get a good freshwater invertebrate book you should be able to tell which types you have. But likely you have a good balance which just reflects a healthy pond.
If you have the medicinal leech (Hirudo sp) I think these are protected now as fairly rare. There are some others that are rare as well but can't remember their names at the moment.
I think they must be Erpobdella, no.8 in this picture.
(http://www.unet.univie.ac.at/~a9909062/Bach/image026.jpg)
I looked up the Hirudo and found this beauty. (http://img.photobucket.com/albums/v89/AnthillMob/scared.gif)
I certainly wouldn't put my hand in the pond if I knew that was in there.
(http://www.abc.net.au/reslib/200704/r138958_475481.jpg)
From memory Erpobdella may be No7 - its a long time since I last did an invertebrate sample from a river. Not sure but No8 may be a horse leech - can't remember the latin name.
No 1 is definitely a pisicola - very definite suckers.
Dishwasher salt (salt with no anticaking additives) gets rid of leaches, and they do indeed stick to fish :(
1/2 imperial ounce per gallon for 1 week then do a partial water change of 10%.
Remove any water plants before adding salt as the salt will usually kill the plants.