Leech?

[mistern2005]

Appearantly a colony of these moved into my tank. Other than having a very high "creepy" factor they seem to be completely buried and don't bother my zebra plecos. Any ideas? Should I try to kill them off or just let them be?

The overexposed picture shows the color as it appears. The underexposed picture shows good detail. When stretched out this guy is about 2" to 2.5" (inches).

[Silurus]

Yup, it's a leech alright. You wouldn't want to be attacked by these things when you stick your hand in the tank, so I'd try to get rid of them.

[PlecoCrazy]

A long while back I had a similar problem. The best way to get rid of them and/or reduce the size of the group is to keep the gravel cleaner and do not overfeed. You should be able to suck them up with a gravel siphon while cleaning. Make sure you pick up rock and decorations and get under them. That is where you'll find most of them.

[geminiluna]

How do they get there?

[mistern2005]

Recently I added plants and do feed live foods so they might have been hitchhikers.

Are these guys going to be bad citizens? Just yesterday I pulled out some very small zebra pleco fry, and I assume if the leaches were going to attack anything it would have been the fry. I'm thinking they might not be bad citizens. If the only fault of the leeches is they rank high on the "sleazy scale", I'll probably just ignore them. If there is a chance they could hurt my fish, it will be a different story.

[geminiluna]

Considering I was naive and had to ask how leeches show up in an aquarium, I may not be your best source. But I do believe that leeches can transmit blood-borne parasites from one fish to another. Not knowing what type of environment these leaches were in when they hitch-hiked into your aquarium would give me cause to wonder if they could transport infectious agents and pose a risk to your zebras.

[mistern2005]

My zebras have shown no sign of distress or injury - actually they spawned just a few days ago. I still feel the question remains whether these will be bad citizens? And, if so, what should I use to eliminate them - keeping in mind I have blackworms, snails, and shrimp living in the tank.

[dw1305]

Hi all,
They are very likely to be a leech species that doesn't attack vertebrates, the leeches are all carnivorous, but a lot eat other worms, small invertebrates etc.

Unfortunately they are difficult to ID. without a key and binocular microscope.

I often find them in my tanks, and they don't stop the Apistogramma spawning successfully, but they may eat the eggs of egg scatters etc.

You could try a meat bait in a net at night, you will probably find more leeches and plenty of Planaria.

cheers Darrel

[mistern2005]

I've almost decided that I can't tolerate the "creep factor" of the leeches.  Is there a way to chemically eradicate them without harming my fish or plants?  I have some fenbenazole around, but I'm unsure if this will work and the proper dosage.  Any helpful advice is very much appreciated!

[mistern2005]

Any ideas about safely eliminating these creepy things?

[PlecoCrazy]

Dead or alive your're going to have to suck them up. I'd remove all the decor and start siphoning.

[mistern2005]

Here is the thing, if I start sucking them up while alive and miss a few (which I will inevitably do) I'll be back to where I started from. I'd greatly appreciate a suggestion of some sort of "safe" chemical warfare I can wage to prevent their return.

[mistern2005]

I know this is an old thread, but I am looking for new ideas.

After a long period of joyful bliss, I suppose these leeches have reached their tipping point. The oldest adult leeches are dying off - to the tune of several per day. One might think this a good thing, however I am having to remove bodies on a daily basis. Not that big of a deal...until I go out of town for two weeks in a few months. Then what?

Does anyone have a good clear, specific way (like dosing instructions) to help eliminate these things?

[donpetty]

There are several medications that may be effective for these leeches. However it should be understood that treating for the removal of the leeches will effect/kill any snails and will also kill your inverts (Shrimps) If you have a place to remove the shrimp and any snails that you want to keep then move them to another tank first.

The following meds should work pretty quickly. I’d recommend a good water change first and gravel vacuum if you have gravel substrate or a water change drawing as close to the bottom as possible if you have sand. I was able to grab some information for you from a site I often reference when treating newly acquired Cory’s.
http://www.americanaquariumproducts.com ... aziquantel


Medications:

A product called CLOUT (Trichlorfon) is easily obtainable and works. However,CLOUT can be dangerous for use on scale less and silver scaled fish.
From the web: Dosage: There is no recommended dosage (other than Freshwater fish acute toxicity= 1.6-180 ppm), refer to manufacturers directions for all products containing Trichlorfon. Sorry not a lot of help with clear dosing on the internet.

Or/ Praziquantel or Tetra/Jungle Parasite guard; Dose 5mL to each 20 US gallons or if using the tablets: 1 tablet per each US 10 Gallons (From package) Again will likely kill snails and shrimps. I have used this product very successfully when treating newly acquired Corydoras especially wild caught that I suspect having parasites.
Or/ Try Levamisol has a wide range of anti-nematodic (worms) effects.
Dosing from the internet: Dosage: Refer to product instructions containing these medications (Do NOT use any of these in the presence of invertebrates). If Levamisol cannot be located, the use of Levamisol HCL found in many commercial dog, poultry, cattle, etc. wormers can be substituted. (Pet Wormers)
59 mg of Levamisole HCl is equivalent to 50 mg of pure levamisole.
2.36 mg/L (or 9 mg/Gallon) of Levamisole HCL, so approximately 90mg of Levamisole HCL will treat 10 gallons (38 liters) with a required 2 ppm concentration. Since Levamisole can be safely over dosed (with a considerable safety margin), approximately .019 teaspoon will work per 10 gallons.

The things I would be concerned about are; death to any sensitive fishes, death to any useful snails; Tylos or Assassins, and death to any shrimps or crabs; also a mass die off of leeches could cause a mess if your not there to do a large water change. So treat only when your able to supervise for at least 2 weeks.
Hope this helps,
Don

[dw1305]

Hi all,
They are really difficult to syphon out as they adhere really firmly with their sucker to whatever they are attached to. I'd try baiting with a prawn in a net at night, and just remove and dip in hot water. You will be amazed how many you have.

cheers Darrel

[mistern2005]

Thank you both for the most recent posts. I am thinking it is time for chemical warfare....

Don, I am going to follow you recommendation on Praziquantel. Thankfully there are no other inverts in the tank to worry about. I'll update the thread with my progress....

[wijnands]

My mother's wildlife pond always had some leeches in it. Hardly ever a problem until one year when their population exploded and they went for anything with fins. We had quite a lot of success by baiting them with a piece of fresh, red, bloody beef on a piece of line. Just don't pull it out but scoop it out wiht a net was the key.

[dw1305]

Hi all,

I am going to follow you recommendation on Praziquantel.

This will kill both Leeches and Planaria, but I'd strongly recommend reducing their number first. During the day they will congregate under stones, wood etc and can be removed by hand (just drop the stone into very warm water to kill them). If you combine this with the baiting method "Wijnands" and I have used successfully, this should thin the number down before you use chemical methods.

For every Leech and Flatworm you see, there will be x10 you don't, and a complete kill may lead to water quality issues.

Personally I want tank stability above all and because of this I only use any chemicals when all other options have been exhausted.

cheers Darrel

[naturalart]

You are probably in the chemical process by now, but if not, I will add: what about the option of transferring all fish over to another tank and letting the original tank and substrate go bone dry? Then rinse out carcasses, treat chemically (optional), then rinse again?

[mistern2005]

All are very good points - I do plan to remove as many of the leaches that I can possible get my hands on before I start treating the tank. These guys do in fact congregate under rocks, in the substrate (which I have very little), and tight places in general. Absolutely - for every 1 you see there are 10 hiding and plotting against you.

My plan was something like this -
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.

Thank you all for the helpful advice.

[Mike_Noren]

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.

[dw1305]

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

[mistern2005]

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.