Leeches?

[starlight]

Are leeches a natural part of the ecosystem in small natural garden ponds? If they are, do they have predators in this situation and what damage, if any, will they cause to other species?

[naturelover]

hi starlight,are you sure they are leeches,i thought i had them but they turned out to be some sort of fly lava.

[starlight]

Im pretty sure, leech like movement. I have put in a tiny bit of mincemeat and it appears to suck it then go with nothing for long periods.

[smartie]

We certainly do get leeches in our pond, but I'm afraid I can't answer your other questions, as I only tend to see them when we clear out some of the weed and they appear out of the debris.

[starlight]

Ok thanks for your reply, I guess they are naturally occurring then, possibly on birds feet of frogs that wander in on their own.

[Adam Cheeseman]

Originally Posted by starlight

Are leeches a natural part of the ecosystem in small natural garden ponds? If they are, do they have predators in this situation and what damage, if any, will they cause to other species?

Hi Starlight,

Yep leeches are a natural part of a pond ecosystem. I'm assuming you have one of two common species in your pond Erpobdella (liver coloured) or Glossiphonia (light yellowish-green). Most Leeches are sanguivores - they attach themselves to prey and suck blood. Others are are carnivores in they hunt and eat prey (bit simplified). Most pond leeches target snails and molluscs primarily for their food. I'm not sure what eats leeches but I guess beetle larvae and dragonfly nymphs wouldn't be beyond giving them a go.

Cheers,

Adam

[starlight]

Thank you for that great info Adam, it is liver coloured with 2 pale patches, there are snails in there too, but none seem harmed in any way. All these are in a tub at present so I have been able to observe them. As my pond is not finished yet.

I have not seen the leech at any time sucking, chewing or molesting any of the snails, but it has gone for small bits of mince, which the snails finish off.

[therealbobbo]

When I had a pond,ocasionally,I noticed oval shaped leeches on fish.As it was a small pond,9x6x2,they were easy to net,and once out of the water,they dropped off before the fish became distressed,and very quickly died.bobbo

[galanthus]

Thanks for that info Adam, it explains a recent mystery.

I had 2 lovely, naturally arriving, ramshorn snails, however, they were outnumbered by an abundance of pondsnails. I found leeches around 5 months ago, amazing creatures and they're welcome in our pond as I believe a pond finds it's own natural balance. Anyway, I was commenting this week that I hadn't seen a water snail, I thought they were possibly hibernating, however, on reflection, we haven't seen any for some time. I think now maybe the leeches have scoffed them.