Help with internal parasites, again...  Mollies   9/1/07
Hello Crew!
<Greetings.>
I've had a few long chats with Tom about my Mollies with internal parasites. This has proven as hard to get rid of as ich and killed many fish.
<Curious. My first question when people have problems with mollies is whether they are keeping them in freshwater or in brackish/marine conditions. In the former case they seem to me to be irredeemably delicate, and successful maintenance requires excellent (i.e., zero nitrate) water quality. In brackish/marine conditions mollies are basically indestructible. For me, it's a no-brainer: if you want to keep mollies with the minimum fuss, keep them at 25-100% seawater salinity (~SG 1.005-1.018). Ich/whitespot cannot survive under such conditions, Finrot and fungal infections are extremely rare, and internal parasite "spores" (or whatever) cannot survive the saltwater conditions so cannot infect healthy fish.>
It all started when we lost one small black balloon Molly, and then realized that her companion was getting way too thin and had the red worm-thing sticking out her anus. We tried Metronidazole and a variety of other medicines, but she died despite our frantic attempts at a cure.
<Why did you use Metronidazole? That's a drug primarily for internal bacteria and to a less extent protozoan parasites. As far as I know, it has no effect on multicellular parasites such as worms. For those, you need something worm-specific (i.e., an anti-helminth drug) such as PraziPro or Sterazin.>
So, when we got two new balloon Mollies, we treated them in the quarantine tank with PraziPro (which is supposed to be effective) before we let them join the two remaining healthy fish. We added them to our apparently unaffected two remaining bigger Mollies, who came from a different dealer (one orange male and one spotted female). We lost the male two weeks ago (within three days he stopped chasing the females, then one morning was lying at the bottom of the tank gasping, then he was dead, no symptoms of anything). My boyfriend just called to tell me the spotted female died today, and apparently she has this red worm-thing again. What's worse, one of the two living Mollies has a distended anus with some white tube-like stuff protruding.
<This is a dumb question perhaps, but are you sure the problem here is worms? Parasitic worms generally don't cause quick deaths. What you tend to see is a gradual loss of condition or a failure to grow or put on weight. By their nature, most of these intestinal parasites have evolved not to kill the host outright, since they die when the host dies. Wild fish commonly carry a parasite load, but otherwise aren't harmed. Nine times out of ten, mollies die from nitrate poisoning, Finrot, fungal infections, or acidosis. This is especially true when the die "quickly". Gasping, for example, is a good sign of respiratory distress, which can be caused by poor water quality and a too-low pH. Just a reminder, mollies in freshwater conditions (if you're foolish enough to keep them thus) need three specific things: zero nitrate, pH 7.5-8.2, and hardness not less than 20 degrees dH. In brackish/marine conditions, the sodium chloride will detoxify the nitrate so that isn't an issue, and the other salts in the marine salt mix will raise the pH and hardness automatically. Please note that "tonic salt" or "aquarium salt" won't do anything other than mitigate the nitrate, so are a greatly inferior product when keeping mollies.>
He's moving them to our quarantine/treatment tank as we speak and will start treating with PraziPro again. Should I also give them Metronidazole? I know they can be mixed, but it's not supposed to be super effective against those kinds of parasites. In any case, I'll follow your advice.
<PraziPro yes, Metronidazole no. As a rule, unless a qualified animal healthcare professional has said otherwise, you should NEVER mix medications. The synergies between two or more drugs are unknown, and potentially lethal. But more importantly, sit down and review your water conditions and chemistry. If you're keeping your mollies in freshwater, please understand that you will always be fighting to keep them healthy. It's just the way it is with mollies. While they are certainly freshwater fish in the wild, in aquaria they just don't do well kept thus. Spend any time reviewing the livebearer e-mails here, or postings on fish forums, and you'll see that there are always bucket-loads of messages about sick mollies.>
Now, the only remaining animals in the tank are a Nerite snail and two Amano shrimp (maybe a few Cherry shrimp too but we haven't seen them in a while).
<Ah, now the good news here is both Amano shrimps and Nerite snails are salt-tolerant, so you can raise the salinity of the tank to SG 1.003-1.005 without problems, should you choose to do so.>
Do I need to treat the main tank to ensure that all parasites are gone? The fish are apparently reinfecting each other, and I want to ensure that they don't get sick again when I put them in the main tank. Do I need to leave the aquarium fallow? If so, how long? Do I hunt the shrimp and move them out, then treat the whole tank? Help!
<Yes, you need to treat the tank. Yes, you will probably need to remove the shrimps, as they tend to be sensitive to medications.>
Do I need to treat the Betta and his Eclipse III too? He used to be in the same aquarium as the Mollies, he might have been exposed...
<Probably not, unless you see some symptoms.>
I know many people say that healthy fish "strike a balance" with their internal parasites and live in apparent health for years with them.
This hasn't proven true for me, those are nasty little bugs (and tough too, after a week of PraziPro the worm was still hanging on) and I'd be extremely glad to be rid of them, once and for all.
<My suspicion is that you're dealing with mollies that are fundamentally stressed, and the worms are at best an "excuse" for them to wave a little white flag and give up.>
Those have to be from the LFS, and they must have lived for months with the things in their digestive systems without showing any signs, since we haven't given them anything else but Nori, flakes, sinking pellets and bits of corn for about a month. They also get frozen bloodworms, and occasionally brine shrimp, but they're both Hikari brand that's supposed to be well sterilized.
<The foods you list should be fine. Do bear in mind mollies are primarily herbivores, and the ratio of green to meaty foods should be of the order 80% to 20%. In fact, feeding them exclusively on vegetable-based fish foods (livebearer flake, Spirulina flake, algae pellets) would be entirely acceptable.>
I really don't want to battle internal parasites AGAIN!!!
<If you want healthy mollies, keep them in brackish/marine conditions. If you want to have to deal with "disease of the month" with your mollies, keep them in freshwater. That's Neale's sage advice for the day.>
Thank you so much for your advice... once again!
Merci beaucoup!
<You're welcome.>
Audrey
<Neale>

Re: Help with internal parasites, again... – 09/01/07
Hi again, Neale!
<Hello Audrey,>
Thank you for such a detailed answer. It did make me feel slightly like I was a bad fish owner, but maybe I deserve it for waiting so long to do what I know I should be doing....
> <Curious. My first question when people have problems with mollies is whether they are keeping them in freshwater or in brackish/marine conditions.
*blushing*... I know, I know... All right... I won't ask any questions again until I do the switch to brackish... I've been planning on it for ages, but I was waiting until after we got the new apartment more or less organized so we could move everyone to a brand new 30 gallons... Looks like this is the signal to get a move on...
Incidentally, we never detect any nitrates. We have plants and a healthy dose of algae so I suspect they get used up before our test kit can detect them. We also had a light fish load, four very small Mollies (balloon variety, they never grew) in 10 gallons (I know, too small, we'll wait until we get the 30 gal we're planning on before we get any more fish, but with the move we've had to buy essential furniture before we can think of a new aquarium). The LFS tells us we can put 10 Mollies in a 10 gallons... (!?!?!?!?!?!) Let's just say we have learned very quickly to take their advice with a big grain of salt :-) pH was always at least 7.5 and climbed very slightly during the winter, high enough that I didn't want to risk most of the fish they sell in the LFS, who need neutral or slightly acidic water. I guess the big problem is with (hardness? alkalinity?), I need to learn what scale it is measured in but the water here is a steady 9.
You're going to say too low, I know. We used to add livebearer salt, but after reading your advice (worthless, waste of money, etc. unless used for a specific problem), we stopped adding it to the tank a few months ago. We'll drop by the marine LFS this afternoon and pick up some marine salt.
<Ah, you seem to understand what's going on, so there's not really much more to add. Mollies just aren't as easy as everyone thinks, with the result that lots of them (most?) get sick and die rather quickly. I'd compare them to goldfish in this regard -- they seem easy, but they're not. For aquarists who want to stick with freshwater, I always recommend platies or swordtails instead. On the topic of pH and hardness, it's almost always safe not to worry about these (within reason). Most common freshwater fish (as opposed to brackish water ones!) can adapt to a wide range of values, so Neons, for example, may *prefer* pH 5.5, near-zero hardness, but they'll *thrive* at pH 8, 20 degrees dH if acclimated to it carefully and otherwise looked after properly. What matters isn't so much the values as the *stability* -- what most fish hate is pH and hardness levels that bounce around. In other words, get fish that are already thriving at the retailer, keep them in your local water conditions, and use good filtration and regular water changes to optimise water quality while diluting the background water chemistry changes that happen in freshwater tanks anyway.>
See... sometimes it takes fish dying so that we learn. Another red flag should have been that they've never bred... we thought our male was sterile because try as he may, he could never get one of them pregnant. In retrospect, maybe they were just in the wrong conditions to breed.
<Quite possibly. But just as likely the fry got eaten or sucked up the filter or whatever.>
> <Why did you use Metronidazole?
Ah, well, because the only symptom we had was one dead emaciated fish and one very thin, formerly very plump, fish and we didn't know what she had, and this was recommended by the marine LFS and was the only thing we could find FAST! The local LFS have never heard of a cure for internal parasites. They just let them be. We did our best on short notice. And then we did more research, and found out about Praziquantel and other medicines, and tried to get some locally but *nobody* sells it around here, we called about 6 places, so I tried to mail-order it, but the two Canadian mail-order stores I know of didn't have it in stock, so we ordered Jungle Labs medicated food, which they wouldn't eat, and then we ordered Gel-Tek, which does contain some Prazi, but that didn't work, and finally the mail-order place got some PraziPro in stock, but by the time we tried that I think it was too late and the fish died, with three very visible red tails sticking out of her anus. But at least we'd finally got to the right medicine - I think.
<I see. Sounds rather bad luck.>
> <This is a dumb question perhaps, but are you sure the problem here is worms? Parasitic worms generally don't cause quick deaths. What you tend to see is a gradual loss of condition or a failure to grow or put on weight.
I think this is exactly what we were seeing, but didn't recognize it in time. We've had some of those fish for six months and they haven't grown. It's just so gradual that we don't notice until the fish are too feeble to function properly. They seem fine, and then one morning they're not quite right, and a week later, they're dying. They never get to the not eating stage. I'm not saying their death can't be due to something else, and it might be more than one factor, but my test kit tells me the pH is steady at 7.5 and that there are no nitrates.
What I see is fish that won't grow, and that after a few months just stop functioning. When the male died he hadn't chased the females for about a week, maybe more, we just didn't notice at first... I feel bad for not noticing those things, but they happen so gradually... and when we did notice something wasn't quite right we didn't know what the problem was.
<OK. Again, you seem to have a sense of what's going on already, so all I can add here is a second opinion. Often, fish deaths come about from multiple small factors acting in concert. Much as with sickness in humans. So you need to watch for the small signs and act swiftly. Odd behaviour is often one of the very best clues, and a lot of experienced fishkeepers will hardly ever need to use test kits because they can spot when things aren't right in established tanks because the fish aren't doing what they should be doing. I don't recommend that approach for beginners of course!>
> <PraziPro yes, Metronidazole no. As a rule, unless a qualified animal healthcare professional has said otherwise, you should NEVER mix  medications.
Ah, but in this case, we know they can be mixed safely because most general anti-parasite medicines contain at least those two, and sometimes other medicines too. But if you say Metro is worthless in this case, I won't use it. This is my understanding as well, but sometimes we bow to people of superior knowledge, so I was asking just in case, because I have some in my fish medicine cabinet...
<I'm not an expert on antibiotics for fish -- they're essentially prescription-only in the UK, so when you get them, the vet will tell you exactly how to use them. I'm happy to let others give you relevant advice here. But me, I prefer to use medications sequentially. It's also important to identify the problem before using the medication; scattergun approaches are risky because many medications can stress the fish, and if they aren't fixing one problem, they could end up causing another. Mollies should be fine, but things like loaches and pufferfish often react badly to medicines, and stingrays and invertebrates can be killed outright. So you need to treat medications with respect. Identify the disease, choose your drug, and look out for side effects.>
> <Ah, now the good news here is both Amano shrimps and Nerite snails are salt-tolerant, so you can raise the salinity of the tank to SG 1.003-1.005 without problems, should you choose to do so.>
Yup, that's exactly what I was planning on when we got the 30 gal. I didn't want to do it with the Cherries in there, because from what I read they're not salt-tolerant at all, and I can't put them with the Betta because he'd rip them apart (he did it before, so we tried some cheap Ghost shrimp, and only found shrimp bits...). I was also trying to find a supplier of Bumblebee Gobies, for the future, and I have lists and lists of salt-tolerant plants, and know the ones we have now *should* make the switch (Bacopa, Anubias, Java fern, and Vallisneria in "quarantine" so we can screen for snails). We're all ready. We just haven't done it yet.
<Very good. I'm not sure whether Cherry shrimps are good in brackish or not. I'd personally risk it, at least to SG 1.003. Shrimps tend to be salt tolerant (many, though not Cherries) have a marine stage in their life cycle, as is the case with Amano shrimps. Acclimating slowly is perhaps the key. I keep (and inevitably breed!) Cherry shrimps and have found them to be rather robust animals, for their size. All your plants are good brackish water denizens, and assuming you have enough light and good substrate for them, will adapt readily. You've also got a nice mix there. When people rely solely on slow-growers like Java fern and Java moss, they end up with algae problems. Throwing in some Bacopa and Vallis should help a great deal. Indian fern is another good algae-beater that tolerates low-end brackish.>
> <My suspicion is that you're dealing with mollies that are fundamentally stressed, and the worms are at best an "excuse" for them to wave a little white flag and give up.>
Then I'll work under this assumption. I promise not to bother you again with my Mollie troubles until they're safely in brackish water.
Then, if I'm still having problems, I'll let you have a go at it :-)
<Heh! Brackish water doesn't fix everything, and it certainly won't cure infected mollies of things like intestinal worms. But what it does do is make them orders of magnitude more robust, and the salinity also suppresses many external parasites as well as the infective stages of certain internal parasites. This is why brackish water fishes have a reputation for being so hardy.>
> <The foods you list should be fine. Do bear in mind mollies are primarily herbivores, and the ratio of green to meaty foods should be of the order 80% to 20%. In fact, feeding them exclusively on vegetable-based fish foods (livebearer flake, Spirulina flake, algae pellets) would be entirely acceptable.>
Yes, they've been getting Nori at least a day out of two. I tried peas but they don't eat it, but they do like corn. I'll try broccoli next.
Can you believe I haven't ever seen a vegetable-based flake around?
Sometimes I feel aquarium shops around here are 20 years behind the times... Even the sinking "algae" pellets have fish flour in them, sometimes even as the first ingredient, so they're not really vegetarian... I've been looking for something called "Spirulina flake" but haven't seen it, just regular flakes with Spirulina among the other ingredients. *sigh*. Maybe I'm simply not looking in the right places. In the meantime, we got some Nori for free at the local sushi place, we just ask for a sheet when we pick up some takeout and with only four small fish, it lasts a long time... and the Amano love it too.
<Interesting. I picked up Spirulina in a grocery store called Hy-Vee in Lincoln, Nebraska over Christmas. So I suspect it's a case of looking out for the stuff while you're on your travels. It isn't critical though. You might even grow your own: a plastic goldfish bowl placed outdoors and filled with water will quickly develop a nice flora and fauna including insect larvae and thread algae. Yum, yum! I love taking this approach, because my "live food ponds" become interesting aquaria in their own right.>
Interesting unrelated tidbit, our Betta eats everything, either floating, sinking or lying at the bottom of the tank (flake, sinking pellets, Betta food, live shrimp, dead shrimp, bloodworms and brine shrimp, peas, corn, everything we ever put in his tank). He even tried Nori. Well... he tried it the first time we gave it to him, but stubbornly refused to taste it ever again :-) I guess even the most wide-ranging tastes have their limit :-)
<Indeed! But that's the right approach to feeding fish. Let them have a little of everything.>
Thank you again, and sorry to be such a bother :-)
Audrey
<Not a problem. Good luck, Neale>