PlanetCatfish.com

For what it's worth(tm) and I'm Not An Expert(c), many, perhaps most, species of leech are not parasites but small predators who scavenge and eat snails and worms.

That said, I know of one documented case where a snail-eating leech attacked and killed guppies, so even the non-parasitic species may not be entirely safe.

Hi all,

many, perhaps most, species of leech are not parasites but small predators who scavenge and eat snails and worms.

Possibly why they haven't been attracted to the bait. The ones I have are Planaria sized and translucent cream (although you can see the sucker etc with a low powered microscope), they definitely don't parasitize the fish, but they are very attracted to dead prawns("Shrimp" to Americans), you can see their distal end "waving" in the current as they move up current towards the food (presumably they are sensing molecules in the water).

1) Clean out as many leaches by hand possible
2) Bait overnight (although I've had almost no success with this)
3) Medicate the next morning
4) Hourly tank checks - pull out any dead/dying leaches (Saturday/Sunday)
5) Do water changes as necessary
6) Hope for the best.

Seems a sensible approach, best of luck.

cheers Darrel

Well talk about throwing a wrench in the plans....

I purchased some API General Cure Anti-Parasite (250 mg Metronidazole and 75 mg Praziquantel per packet). Each packet is supposed to treat 10 gallons. Before taking apart everything, I sequestered one poor leech in a 1/2 gallon container and added one whole packet to the container to verify the intended effect. Bad news...it had no effect on the leech!

I've dosed Levamisole in the past with good success and little to no effect on the fish in my tank. I guess we are on to treatment attempt #2.