As it was a sticky in the previous BCA server, I thought people would want this back up....
I thought I'd post one of my articles which I had written for the Vancouver Aquatic Hobbyist Club news letter. The reason I thought it was worthy of posting is because lately people have been experiencing these nasty worms (nematodes). Anyways, enjoy!
Parasitic nematode: callamanus worms
Many years ago I received a handful of angle fishes from my cousin which I placed in a tank of their own. It wasn?t until a month after I got the fish that I noticed that they had little red worms sticking out of their vent (anal opening). I was surprised since I had never had them before and I really thought nothing of them but just to keep them on their own. As I further did some research on the worms, I soon found out that they were callamanus worms, or more specific, a parasitic nematode.
These nematodes are contagious and should be eliminated when sighted. By the time you notice that the worms are protruding from the vent of a fish, the worms will have been in their reproductive stages and may have already released microscopic larvae into the tank.
As an experiment, I threw in a few smaller fish with the infected angels, and I observed. After a month or so I noticed that a few of the introduced fishes had only one or two worms sticking out of them. After about 4 months all the introduced fishes in the tank had it and eventually a few died and the rest I had to put down since they didn?t look so good. And all this time the adult angels didn?t seem affected by the worms. So what did I learn here: first, smaller fishes are more prone to deaths than larger ones and second, they are infectious and quick to reproduce. The results are based on a single experiment and may mean nothing, but I took the results seriously and was not willing to kill more fish to find out. I had to decontaminate my tank and angels of these parasites.
I found that a medication which claimed to work very well was called Levamsole HCl. This particular medication was specifically for larger animals such as cattle, pigs, and sheep. However, a few sites demonstrated that the medication can also be used in fish with great results. I had to get some medication as soon as possible.
Upon purchasing the medication, I treated the tank. I dissolved 5 grams of pure Levamsole HCl with 88 ml of water. For every gallon of fish tank water I added 1 ml of the dissolved Levamsole HCl. Most of the angels fishes had the worms sticking out of their vents, however after a few hours of treatment, more worms were protruding out of the fishes. The next day, even more worms were protruding and a few almost completely out dangling a good centimeter out. It is often difficult to tell the amount of infestation by just looking at the vents of the fish until treatment was conducted. When they were infected I only saw at most 2-3 worms sticking out of the fishes. After treating the tank, I saw as many as 12 worms sticking out at once and was soon to be released from the fish. Every day I did water changes (to remove the feces and any worms) and fed the fish lots of food. I noticed that after the second/third day, the aggressiveness of the fish towards food was greater. They were more eager to eat and less shy. It seems that there was a change in behavior and that the worms really did affect the fishes. By the forth day, all the worms were no longer present (sticking out of the fishes) and I even got a pair of fish to start spawning. The results may vary but I certainly would agree with anyone who would think that removing the worms is better than just leaving them in the fish. I find through experience that smaller fishes don?t do well when infected and will not last long. Compared to larger fishes, such as angels, I find that they can tolerate the worms and seem to look okay, however, the behavior is a bit more shy. For smaller fishes, I noticed that once infected, they only last for about 4 to 6 months and possibly 7 months. In my angels they have lasted for about 1 year without mortalities. Keep in mind, you should always be doing water changes when treating your fish making sure that you take out any fecal matter since possible worms and larvae may be within the feces. As for the parasitic nematodes, I have not seen them since and I?m keeping my fingers crossed!
Here is a photo of a few nematodes which I pulled out from an apistogramma:
Here's one from a live fish: