Fungus killing larvae & pond fish

[larah]

Sorry for the long post but please read!

I recently started feeding my CB Taricha granulosa larvae red (tubifex?) worms from my mom's outdoor pond. However, the fish in the pond have developed some sort of fluffy/stringy white fungus stuff and I am suddenly losing my larvae to the same thing. The fungus attacks quickly and usually appears on the very tip of the tail or the forelimbs (the larvae are small, most only just beginning to get their back legs). I separate any larvae that look affected, sterilized the tank, do frequent/full water changes (NO pond water of course), and am feeding them exclusively on baby brine shrimp. Is there anything else I should be doing? Should I put the larvae in separate cups or something?

The other big question I have is what to do about the pond? It's full hyla regilla (pacific treefrogs), rana aurora (red-legged frogs), taricha granulosa (though lots of the adults have finished breeding and left), tadpoles & larvae, and about 20 or so 3-8" koi & goldfish. Some of the fish recently spawned and there were lots of baby fish (they were actually first to get the fungus) but we were able to remove most of them.

Problem is, the pond is irregular and we don't know how many gallons it is (maybe around 600) and don't want to treat it with anything that would be harmful to the newts & frogs. Up until now we didn't realize that the fish could pass whatever this is to them. The only thing that's been added to the pond so far is AmQuel, NovAqua and a small bag of salt (probably not enough to do much, but again, we don't know how many gallons it is). We tried catching the koi and dipping them in antifungal stuff but could only catch about 40% of them. So far the koi/goldfish are the only thing in the pond we've seen affected (adult H.regilla and T.granulosa "look" fine, but of course can't see their babies). Is there anything we can do? Any medication that would work in a pond like this? Water changes afterwards would be difficult, so whatever gets put in the pond would probably remain there for quite a while.

Thank you!!

 

[david]

I don't know how to treat your pond, but if you're having a fungus or infection problem with your larvae, I'd be very careful about cleaning out the uneaten brine shrimp. They can foul the water quickly. Maybe you should try daphnia or live blackworms from a different source. Any particular coloring or swelling on the infected larvae? The reason I ask is if there is only about 600 gallons, with that many koi, frogs and taricha using it, there's lots of waste being produced and probably overcrowding. These types of conditions can lead to various infections.

(Message edited by dln on July 14, 2004)

 

[sharon]

Hey no kidding 600 gl is NOTHING. We have a floating ring pool that is over 1000 gls.

Are you sure about that number?

 

[larah]

Thank you for responding-

No, as I said before, I am not sure how many gallons it is. The pond has irregular angles and an uneven bottom that ranges from maybe 9" to over 18" deep in some places. There are also lots of large rocks and plants in the pond. It could easily be over 1000 gallons. I was surprised when we were getting numbers lower than that after calculations.

I agree that the pond is overcrowded. However, most of the visitors came in on their own from the wild. My mom added the fish to eat the mosquito larvae, and I must admit I don't care for them much. I was hoping the AmQuel and plants would help keep the ammonia/waste problem in check. I would appreciate any suggestions on what else to do.

As for the larvae from my captive newts, I'm cleaning out the left over brine shrimp after 3-4 hours. I run the brine shrimp net over the bottom which seems to scrape up & collect most of them, and then I change as much of the water as I can. Do I need to be removing the larvae all the time to scrub out the tank? I wasn't planning on doing that too often because I thought it would stress them. I'm all out of blackworms right now, I'll go get more. Hopefully they are big enough to handle them now. . . before even after I chopped them the pieces were still pretty big for them and they were spitting them back out. I don't know where to get daphnia unless there's somewhere I can get them online & I thought it took a while to get culture started.

 

[pin-pin]

Hi Larah,

I know it's not advised, but you can try this chemical called "methylene blue" in your larval tank. If the fungus is killing your larvae, then better do something than nothing at all.

If you dip just the tip (4mm or less) of a toothpick into the methylene blue, that is the amount I used per gallon. The color of the treated water should be barely noticeably blue.

If the blackworms are too large, you can try ordering a culture of grindal worms. They do eventually die, but they wiggle for about 1-2 days before drowning. You can get them online at The Bug Farm or other specialty on-line places.

Nice photo, btw.

(Message edited by apples on July 14, 2004)

 

[jennifer]

Hi Larah, lots of issues here.

First, the pond. Can you tell us the approximate length/width? Even without knowing gallons, we can get some idea how big it is. There are lots of web sites to help you calculate the volume. You just need to estimate the AVERAGE length, width, and depth. Here is one site, but there are others that work:
http://www.urdls.com/j/pondcalc.htm

I was told that, to have any koi at all, you should have a REALLY big pond. When a tank or pond is overcrowded, the chances of getting fungal (and other) infections skyrockets. I don't know how to treat it, but future prevention will depend on keeping the number of animals within the capacity of the pond. Can you give some fish away? And try to do some partial water changes?

Regarding the indoor newt larvae, you are doing about the right things. I agree with the suggestion regarding methylene blue. I would encourage you to simply the pour the larvae into a clean container every day or two. I do this, and being tumbled around doesn't bother them a bit.

Yes, it's a little late to get a worm culture going. The easiest thing will be to keep a steady supply of live blackworms, chopped and later on whole. Even if they spit pieces out, they are probably eating some too.

Good luck!

P.S. No a big deal, but... if you got the newt larvae from the pond, and they came from wild newts, you can't call them CB, technically speaking. You can call them captive raised

 

[larah]

I will definitely medicate the larvae if I see any more signs of the fungus, the good news is I haven’t seen any sign of it for almost 2 days now. Here’s a picture of one of the babies with its tummy full of brine shrimp.

Jennifer, all of these larvae came from eggs laid by two of my captive T.granulosa. I’ve had them for years (kept in a tank indoors), even before I moved here, where there are lots of wild newts (cool huh?). They laid eggs after I moved them into a tank enclosure I built and put outside on my porch (the weather’s always pretty mild here). I took the eggs out of the parent tank and am keeping the larvae indoors. The only “contact” they’ve had with the pond is the worms and pond water that I was feeding them. That qualifies as CB right?

I’m going to go take more measurements and maybe a picture of the pond to post later tonight. I guess I could try doing some partial water changes for the pond, but I think it kinda does that on it’s own. What I mean is, the water level goes down several inches every couple days (more than just evaporation loss, I think it has a slow leak) and water is pumped from a creek in the backyard through a fountain to refill it.

 

[larah]

I took some more measurements on the pond and came up with about 1300 gallons. It's the depth that's the tricky part to figure. . . it's really uneven with huge boulders all over the bottom (and 1' deep vs. 2' deep makes a HUGE difference). Here's a picture of it-

 

[ira]

thats a really nice pond. i would definatly take all the fish out of it and just make it a newt pool

 

[jennifer]

Yes, they are CB in that case. That is a lovely pond, I wish I could have one like that! It's good that the pond is doing its own water changes by leaking some. That is probably how it manages to sustain the number of animals it has.

 

[pin-pin]

I wanna be like you when I grow up.