Marine leeches...

Kaboobie · Mar 18, 2020

I have come across something that seems to be rare. Lucky me. My display has leeches. I have removed the fish to quarantine and have potassium Permanganate arriving today to kill the ones on my fish. However how long can they survive in my display without fish present?

They are 100% leeches they have all the correct body structures when the big ones come off it is pretty clear. I can only guess they came in with my algae barn pods or algae order as that is the only addition to my tank in a few months. I have no coral in my tank yet so I can pull my inverts out and dose the display with things if needed.

Pickwun · Mar 18, 2020

Farm them and sell 'em to a biotech company.

Kaboobie · Mar 20, 2020

Here are a couple of pictures of the dead leaches. That I removed with a combination of manual removal and a series of potassium Permanganate dips.

Mike N · Mar 20, 2020

Eww!
I would be very upset if those things came in with an algae order.
Good luck in getting them out of your display.

Kaboobie · Mar 20, 2020

So some disappointing info I have found is that some leeches can live for up to two years without food. So now I guess a nuclear option is in order for clearing them from the display as a typical fallow period seems unlikely to be effective.

Does anyone have a good method for treating a tank to kill them without total annihilation of the beneficial bacteria?

Reaper603 · Mar 20, 2020

I have to be honest I have never heard of such a thing now I know and that is some crazy stuff. So I read these are extremely rare in the hobby but people were trying to figure out how to at least kill them because they say they are very resilient but I copied this for you hope it helps: With any parasite, the most important question is, how do we treat it. Well, we found these leeches to be extremely resistant to most of our treatments, which is unusual for a macro parasite as these are usually easily dislodged. Freshwater dips and praziquantel baths did nothing, as well as acriflavin dips. In the end it was a formalin dip that did the trick. A pretty extreme course of treatment for such a large parasite. Physical removal is not recommended, as it may cause wounds that could be susceptible to infection. Copper or potassium permanganate may be other suitable treatment protocols for leeches.

Kaboobie · Mar 23, 2020

This is the advice I had found about removal from the fish.

Does anyone have any thoughts on how to clear them from the display? I think the ones in my display are all young and possibly have not fed so I'm hoping will starve. I keep checking when I turn on the lights to see if I find any young ones on the glass and am still finding 4-5 every day that are tiny and have clearly not yet fed.

laverda · Mar 23, 2020

Are you removing the ones you see on the glass? If so use them to see what will kill them. First try some of the things safe for our tanks. Hypo salinity, hydrogen peroxide, melaflix, flat worm exit, are a couple that come to mind. Did you tell Algae Barn you suspect they came from them?
Good luck!

Kaboobie · Mar 23, 2020

I have not been removing them as I was using them as a way to monitor if they were dying off from not having a food source or not but I may remove a couple and try some different treatments as that is a good idea that I didn't think of for some reason.

Kaboobie · Apr 27, 2020

So just to give an update I ended up monitoring the tank and the little tiny unfed leeches were not disappearing so I put the fish back and simply removed them daily for three days until I no longer saw them on the fish or the tank. I have not had them recur as of this time.