Treatment

While I was very optimistic about fenbendazole as a treatment option, I'm a little more worried now. After two days of treatment, I don't see fewer Camallanus worms hanging out of the fish. I am very concerned about whether the fish are ingesting enough of the drug, especially the smallest female Macropodus, which also seems to be the worst infected. I have soaked a mixture of foods in a fenbendazole suspension, and I'm hopeful that they are getting enough of it, but the only way I have of monitoring the treatment is by looking at the worms hanging out of the fish. They still appear red and healthy, which isn't a good sign. This is the final day of the treatment course, so I was hoping for some visible results. "TheGreatBlueDiscus" had visible results after 36 hours, but since he was treating his fish twice a day, that amounts to three treatments.

Since I won't be able to continue the treatment over Christmas, I'm seriously considering euthanising the Macropodus. Not something I would want to do, but I can't afford dead fish floating around the tank for several days (there's only so much my plague of snails can handle).

Timeline of infection

A parasitic nematode like Camallanus needs to get into the aquarium from somewhere. I've been thinking about possible paths of infection. According to Levsen and Berland (2001) Camallanus cotti takes 11 days to fully develop in its copeopd host, and then another 34-42 days to develop after it is ingested by a fish host. Presumably the adult feeds for at least a few days before it extrudes from the anus of the fish and starts releasing larvae of its own. Levsen (2001) found that it took a minimum of 62 days and a maximum of 110 days for visible signs of the parasite in a system with monoxeny - direct (fish to fish) infection. Since I first saw signs on the worms in mid-December, they became infected somewhere between early September and early November. That said, I first noticed the worms last weekend, and once I looked there were worming hanging out of several Macropodus.

In that time period I bought (and didn't adequately quarantine) quite a few fish. The fighter is an unlikely culprit - not only did we buy him too recently, he also shows no signs of infection. The pygmy corys are also unlikely, since they have never been in the main tank. On the other hand, the plant tank has a population of copepods, so I would only have to introduce the copepods, not actually any fish. It's reasonable that Camallanus was introduced with infected copepods that came with the Java moss. The timeline is reasonable - about 55 days. I also transferred a couple larger corys from the plant tank to the main tank, and an Otocinclus. They are also potential sources of infection.

There are, of course, other possibilities. I bought three batches of neon tetras this Fall, and had remarkably high mortality. I also bought some ghost shrimp. The ghost shrimp themselves are unlikely vectors - I have not read about Camallanus infecting shrimp, although there's a slight chance that they were using them as secondary hosts. The neons, on the other hand, are another story.

I bought my first batch of neons back in early September. Four of the five died within two days, and that was followed by a wave of mortality: a fighter, two Angels, two platies and a couple Macropodus. It seems pretty obvious that they weren't the ""cleanest" of fish. The extra burden of Camallanus infection could be blamed for the death of the neons (if you're already feeding parasitic worms, you have fewer resources with which to handle stress), it seems unlikely that transmission of the Camallanus larvae could have resulted in such rapid mortality among the other fish.

While I initially blamed the pet store, the deaths of the other fish led me to wonder whether something had gone wrong with my water, and that the timing might have been coincidental. Anyway, the sole survivor remained in the tank, seemingly healthy, but with a shrunken abdomen (which was always a cause for concern). He died a couple months later, after I bought some more neons to keep him company.

I'm most inclined to blame the neons (or more specifically, the one neon). And while I could do a lot to improve my quarantine procedures, segregating new fish for 2 to 4 months just isn't something I can do at present. While I hate the idea of medicating new fish as a precautionary measure, I can see why people would do it.

1. Levsen, A. (2001). Transmission Ecology and Larval Behaviour of Camallanus cotti (Nematoda, Camallanidae) Under Aquarium Conditions . Aquarium Sciences and Conservation, 3(4), 315-325. DOI: 10.1023/A:1013137801600
2. Levsen, A., Berland, B. (2002). The development and morphogenesis of Camallanus cotti Fujita, 1927 (Nematoda: Camallanidae), with notes on its phylogeny and definitive host range. Systematic Parasitology, 53(1), 29-37. DOI: 10.1023/A:1019955917509

First casualties?

While the Camallanus still appear well (there are still red worms hanging out of most of the Macropodus), one of the male Macropodus died. Was it worm-related, meds-related or just coincidence? I'm inclined to think it's something other than coincidence. After all, the only visibly infected fish are the Macropodus, so I'm guessing that they are more susceptible to the Camallanus.

It makes me wonder whether there's a stress component. The Macropodus are likely to be the most stressed fish in the tank, since their struggles for dominance consume a lot of their energy. Interesting thought.

Camallanus biology

One of the challenges of home diagnoses is "getting it right". Based on the University of Florida IFAS Extension document (Yangong 2006) on nematode infections in fish, a diagnosis of Camallanus infection seems reasonable. But, like any biologist, my first question is: what species? Is there only one species that you tend to find in freshwater aquaria, or are there many?

According to Yanong, Camallanus requires a secondary host, usually a copepod. I suppose a moderately planted tank with driftwood has lots of room for copepods, even if I can't see them. There are enough hiding spots for them in there. So I'm guessing that control of secondary hosts really isn't an option.

"The dreaded Camallanus worm"

On Sunday I noticed something red and spiky protruding from the anus of one of my female Macropodus in the main tank. When I looked at them carefully, I saw something similar on one of the males. While I had never seen anything of the sort before, it was easy enough to recognise based on the descriptions I had read online - my tank was infected with "the dreaded Camallanus worm". A quick Google search reveals two things - one, that aquarists dread this worm (a genus of parasitic nematodes), and two, that there are two fairly well-established treatments: fenbendazole and levamisole. Fenbendazole is a common dog dewormer, and levamisole is apparently used for pigs. Fenbendazole was available at the pet store locally, so I went with that. However, levamisole is probably easier to use, since it can be applied to the water, and is usually effective with a single treatment. Fenbendazole needs to to ingested by the fish, and involves a three-day treatment cycle, followed by another treatment two weeks later. Since the fish have to ingest the drug, the issue of dosage becomes very complicated. On the other hand, the more powerful a drug, the more suspicious of it I am. I was reassured by the low level of warning on the fenbendazole package as well.

Based on what I could find online, I decided to make a solution (or suspension) of the fenbendazole and soak bloodworms in it. For good measure, I also added some sinking pellets to the mix. The fish at both quite happily, so it does not seem like the drug made the food unappealing (either that, or it didn't soak in well enough, which is a concern of mine).

Like everything else in the world of fishkeeping, the major source of information out there is the bulletin boards. And like everything else, I'm hesitant to trust them. I'm glad I came across this University of Florida IFAS Extension document. It was also nice to find this essay at PetFish.net - most people use levamisole, so it's nice to have something against which to compare my own experience.

Main tank

Yeah, I know...it barely deserves the designation "planted tank", but that's without carbon dioxide injection or "adequate" lighting.

Experimenting with Excel

I bought a bottle of Seachem's Flourish Excel - apparently it's basically glutaraldehyde, which serves as a source of bioavailable carbon for aquatic plants (but not algae). It's also supposed to function as an algaecide, especially at higher concentrations, although it isn't actually marketed as such (see Seachem's FAQ; there's also a lot of talk about this on discussion fora).

While I'm terribly curious about the mechanism of action of glutaraldehyde (or whatever it may break down into), I'm mostly curious about whether the plants in my main tank are CO₂ limited. My light levels are well below what's recommended, but when people talk about planted tanks, they talk about light and carbon dioxide. Given my current light levels, would my plants be able to utilise additional carbon? I hope to find out.

Not shrimp?

I feel fairly confident that the smaller organisms swimming around my plant tank are not baby shrimp. I'm guessing they're some sort of cladoceran that got introduced either with the plants or the fish or shrimp or, for that matter, on a rock, in some dust... The unusual thing probably isn't getting things like that into your tank, it's a matter of their finding predator-free space. The current inhabitants of the tank (Cherry red shrimp, pygmy corys, Otocinclus) aren't going to both organisms that stay out of their way. Adding a prefilter also makes the tank more friendly to smaller organisms.

Betta bulbs

It's been about six weeks since I planted the "Betta bulbs" (Aponogeton sp., allegedly A. ulvaceus), so whatever's going to grow has probably grown. Apparently I planted four in the main tank, one in the Macropodus tank, and two in the plant tank.

They grew well in the plant tank. After about two weeks, one of the bulbs had sprouted, and after another week a flower spike broke the surface of the water. While the first one didn't expand, the plant has produced another four in rapid succession. The young inflorescence looks like the top picture. As it expands it ends up looking more like the lower image.

Shortly thereafter, the second bulb in the plant tank started growing, and it too has produced a succession of flowers. Both plants have also produced floating leaves.

Things were a bit different in the main tank. One of the bulbs floated up fairly soon, apparently dead. A second one eventually made it to the surface, and appears to be dead as well. I'm not entirely sure what happened to the other two - there's one plant that's either a young Aponogeton or a Cryptocoryne sucker, and another leaf that could be a second bulb. In both cases, the plants are small and could easily be something else. I haven't seen any sign of the bulb in the Macropodus tank, but that tank has become so heavily overgrown (since I upgraded from incandescent to compact fluorescent lighting) that I'm really not sure that I would be able to find it if it were growing.

Nineteen

Just counted 19 juvie shrimp (and that doesn't include the little dots that are still flitting around). My best prior count was 15. On the other hand, I haven't seen the last adult for several days - I'm getting a little worried about him.

Using OpenID for comments

I added the option of using OpenIDs to comment on this blog, per phydeaux3's blog post. So it should now be possible to leave comments using AOL/AIM, LiveJournal, TypeKey, WordPress or other OpenID logins.

Phydeaux3 also has instructions on how to alter the settings on to allow this on Blogger.

Restricted aquatic plants

As I mentioned in the past, I was surprised to realise that one of the most widely recommended aquarium plants was a federally listed noxious weed in the US, and may be illegal to possess in Oklahoma. Today I came across a notice that possession of Cabomba carolinina is illegal in Maine. With a tankful of an unidentified Cabomba sp., I grew a little concerned. But it doesn't fall on the federal noxious weed list, and it doesn't appear to be on the Oklahoma list. Still, there are a few important thoughts in all this:

• Never release anything from your aquarium into the wild. (That should be pretty obviousl but it isn't).
• Dispose of all plant material with care. While that is especially true in warmer climates, aquarium plants can obviously even be problematics as far north as Maine.
  
• If it grows like a weed, it probably is a weed.

Shrimp skins

After losing three of my four adult shrimp, I was rather concerned when I started finding what looked to be dead juveniles. In the first few cases, I noticed that they seemed rather thin and insubstantial, but after a while I concluded that they were probably shed carapaces, rather than dead shrimp.

That said, some amount of juvie mortality is to be expected. I'm still thrilled with the fact that I ended up with at least a dozen offspring, despite the fact that the tank was very unsuitable for shrimp when they first hatched; the initial setup included a female platy and an unprotected filter intake. On the other hand, the filter box may have provided a refuge/nursery for the young shrimp - since the filter pad was very dirty and the flow was only moderate, it might have been a perfect, food-rich environment for them. Makes me curious how well they tolerate the water flow and whether light is important for their development...