I want to remove the leeches that live in my aquarium. When fundulus mentioned bristle worms, I looked them up and found that people often use traps to catch them and get them out of the tank. Maybe that kind of trap might also work on the leeches. Does anyone have any experience baiting leeches or other worm-like things?

I found this design online. Please tell me what you think of it:

How to Fabricate the [Bristle Worm] Trap
* Use a kitchen type container or a used food container made out of plastic. Make sure you have lid for the container. The container needs to be opaque. I have outlined this before. After you have added the food to the trap, lower the container in the water and let it fill with water.
* Place it in the area where you think the bristle worm or whatever else you need to trap resides or hides.
* Before doing this though you need to prepare the trap:
* In the lid make an X shaped cut with a razor blade.
* The size of the X should be just smaller than the thickness of the worm, or Mantis shrimp, or whatever else you are trying to catch.
* Gauge the thickness carefully as the size of the opening in the lid needs to be slightly smaller than the size of the animal you are trying to trap. This is probably the only difficult part in the whole process. Remember that worms can make themselves real thin.
* Push the four pieces of plastic that are loose as a result of the X cut inwards, at about a 45 degree angle. You can do this with your fingers or a tool. They should remain in that position. This is important (see below).
* This allows the animal you want to trap to get in easily, but makes it hard for the animal to get back out. As it tries to get out, the pieces you pushed in will want to come back up as a result of the pressure the animal exerts on them. That is what makes it hard for the animal to get back out of the trap.

Source: http://www.netpets.o...f/bristle3.html

Modifications to the design and other ideas greatly appreciated.

Just found something interesting: an inverted cone entrance way to the trap. Image: http://c1.f3images.c.../ES09550_99.jpg

Have you noticed the leeches congregating on any particular type of food? Liver works well for predatory flatworms, not sure if it works for predatory leeches. You could use it conjunction with the trap, or just drop it in and sweep up the leeches when they gather around it.

Have you noticed the leeches congregating on any particular type of food?

Nope. I've actually seen the leech twice, both times yesterday. The first time I saw it, all I really saw was a traveling hump in the ground, like in the movie "Tremors" or like how Bugs Bunny goes to try to get to Albuquerque. It was really weird to watch; the blackworms were freaking out and I saw one fling itself literally out of the ground and into the water column to escape. I decided not to poke whatever the hump thing was and just leave it alone, but then later that night I saw a leech like basking on the substrate, indulging in the fact that it has no predators.

Anyway, no idea what it eats except for blackworms. Liver is a as good a thing to start with as any.

Edited by EricaWieser, 23 February 2011 - 06:55 PM.

If it's just one or two, you might be better off using some long forceps or hemostats. Less trouble in the long run. Just keep the forceps by the tank and keep an eye out.

If it's just one or two, you might be better off using some long forceps or hemostats. Less trouble in the long run. Just keep the forceps by the tank and keep an eye out.

I did squish one just now. Ew. I'm going to trap them too, though, because I bet it's like it is with cockroaches; if you see one, there are actually a lot more.

I've been weighing the pros and cons of buying a bristleworm trap versus making my own. I do still have this half inch PVC pipe left over. I'm just not sure what type of cone I could use to make this: http://ecx.images-am...L500_AA300_.jpg

Free time met leftover building supplies and I just built one.

Picture log:
http://img.photobuck...imiru/016-3.jpg
http://img.photobuck...imiru/017-2.jpg
http://img.photobuck...imiru/018-3.jpg
http://img.photobuck...imiru/019-5.jpg
http://img.photobuck...imiru/020-1.jpg
http://img.photobuck...imiru/021-1.jpg
http://img.photobuck...imiru/022-4.jpg
http://img.photobuck...imiru/023-3.jpg
http://img.photobuck...imiru/024-1.jpg
http://img.photobuck...imiru/025-2.jpg
http://img.photobuck...imiru/026-3.jpg
http://img.photobuck...imiru/028-5.jpg
http://img.photobuck...imiru/030-5.jpg

I baited it with cocktail shrimp because that's what I had in the freezer. Maybe I'll catch something tonight. I'm going to check it in the morning.

Goal: Catch this:
http://img.photobuck...imiru/014-3.jpg

Edited by EricaWieser, 23 February 2011 - 11:36 PM.

Update:
I checked the trap this morning and the shrimp was still inside, untouched. There were some snails on the outside of it looking wistfully at the entrance they couldn't get in, but that's about it. I wonder if I killed the only leech by squishing it yesterday. Or if there are more in there but they just didn't take the bait. Or if they would take the bait if given another night or two. Hmm.

Goal: Catch this:
http://img.photobuck...imiru/014-3.jpg
[/quote]

Looks like some kind of earthworm to me?

Looks like some kind of earthworm to me?

That is a leech. Earthworms don't move like this:

I think he's kinda cute.

I think he's kinda cute.

I think my blackworms are kinda cute:
http://gallery.nanfa...resize.jpg.html
The leech eats them.

I'm thinking that maybe the one way opening I made was actually a no way opening. It might be more fruitful to just buy the premade one. Hmm.

Suggestions on one way opening designs much appreciated. The "cut an X out and push it one way" just seems to make a lot of sharp edges.

Unless you actually see more leaches I wouldn't worry about buying a trap.

Unless you actually see more leaches I wouldn't worry about buying a trap.

I'm buying a bristleworm trap Friday. This is a recurring problem in my tanks. I've had leeches, despite all my efforts, for the past year now. They have obliterated my blackworm population twice now, in two different tanks, and I'm sick of them eating the Elassoma gilberti's food.

Have you noticed the leeches congregating on any particular type of food? Liver works well for predatory flatworms, not sure if it works for predatory leeches. You could use it conjunction with the trap, or just drop it in and sweep up the leeches when they gather around it.

Beef heart is said to work well too.

Bristle worms are a whole nuther critter. They come out at night and actively forage for any kind meaty food they can find. They also reproduce and survive quite well in tank with enough hiding places and left over food. Very few fish will eat them. I always had them in any tank that had tropical live rock or cultivated rock seeded from wild collected rock. Conventional wisdom says they're bad but I honestly can't remember why. They never bothered me any. Most people don't even know they're there until the move rock around and dislodge one. Then they freak out and go buy some pest solution. The tank and fish were doing just fine when they didn't know they were there.

I've had leaches show up frequently after adding wild plants but they always seem to get thin and eventually disappear. I never saw one eat, never saw one attached to a fish and I never heard of them reproducing. I also never kept live blackworms.
I think it's kinda cool that the blackworm colony provides conditions favorable to leeches. I'd like to observe it myself [summer project ] but I don't blame you for not wanting them to eat the fish's food. Maybe if you observe the tank at night, maybe with a red bulb if they're shy, you can use an aquarium net and scoop them.

I have purchased a bristleworm trap! yay. I'll set it up overnight soon and post the results.

Maybe if you observe the tank at night, maybe with a red bulb if they're shy, you can use an aquarium net and scoop them.

They live under the substrate, moving around by tunneling, and hunting underground too. Have you ever seen the old cartoons where Bugs Bunny is trying to get to Albuquerque? Or the movie Tremors? It's sort of like that, the way the mound moves along the surface because there's a leech moving fast underneath.

Edited by EricaWieser, 06 March 2011 - 02:45 PM.

They live under the substrate, moving around by tunneling, and hunting underground too. Have you ever seen the old cartoons where Bugs Bunny is trying to get to Albuquerque? Or the movie Tremors? It's sort of like that, the way the mound moves along the surface because there's a leech moving fast underneath.

That's exactly how ammocoetes move - it's quite neat actually.