If Your Rasboras Start Dying Suddenly...


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**If your rasboras are dying quickly after displaying symptoms of swim-bladder disease, read this entire post**

I thought this really important to post, as I didn’t find an answer to my problem when I was having it. I did come across a very old post from someone having the same problem, but no one knew what it was. So here is how I learned to deal with it.

Firstly, I’d like to say, don’t buy fish from Walmart. I learned that the hard way. When I was shopping in the pet section, I saw that Walmart had Harlequin Rasboras, and I was wanting some for my tank. So I bought five. They didn’t seem very active, but I thought it was because they were nervous. They didn’t school closely and I thought that was strange. I put them in my tank and they didn’t get any better. They wouldn’t eat but that’s normal for new fish. I just wanted to see how they did.

The next day they started dropping like flies. I noticed one swimming on its back, displaying swimblatter symptoms. But it was worse than that, he was dying. I had to get him out of there because my shrimp seemed to think that he was a snack and started feeding on him. Shortly after that another rasbora was doing the same thing, and the shrimp were after him, too. So I removed him. They both died.

I had come to the conclusion that the shrimp were killing them, as they were ghost shrimp, and I had read that sometimes pet stores would sell palaemonetes vulgaris (aggressive shrimp) thinking they were palaemonetes paludosus (nonaggressive ghost shrimp) because they look so much alike. I tried to identify them, but I just couldn’t tell. I thought the shrimp were harassing my small rasboras (they were very young) so I removed them and put them in another tank.

However, they kept showing the same symptoms and dying off. I noticed that some who had already been munched on by the shrimp had injuries, so I treated them with melafix and stress coat to help heal them, and to get rid of any disease that might be in there. It seemed to work, though all died except one.

The one was getting better, though still not eating. He seemed really upset that he was all alone. I’d planned to get more if he survived, but at this point I still thought that it was the shrimp that caused it, though I wasn’t sure. After a day I decided to put him back in and monitor him, hoping that maybe he wouldn’t be as lonely with the other fish in the tank around. So I put him back in and monitored him to see if the shrimp would bother him. They didn’t, and he seemed to be doing fine, even playing in the current and bubbles. I had hope.

The next morning, however, he was dead and lying on the filter.

A few days later, I wanted to try again, this time from another store. I got five more rasboras and two female platies. They were so lively! They were actually healthy, and they started eating shortly after I put them in the tank. The rasboras would chase each other around and play in the current. I was happy to see them take to the tank so well.

The next day, to my horror, the rasboras started displaying the same symptoms that the previous batch had before they died. Within an hour they started swimming on their backs and lying on the floor of the tank, at witch point the shrimp would think they were food. I took all of the rasboras out immediately so they wouldn’t be bothered by the shrimp, which were clearly only going after the dying ones.

I finally realized that this is a mystery disease, as I found nothing online about it, to my dismay. I started treating both tanks with melafix. Even though the illness only affected he rasboras, both tanks were contaminated, so I needed to treat both. I continue to treat them separately, and when the treatment was over for both tanks, I put the remaining rasboras back in with the other fish.

The melafix worked, so it was clearly bacterial, though I don’t know what it was, and it only seemed to affect the rasboras. Only two survived. By the time I had began treatment there were four, and one was definitely not going to make it, the other had already turned on its back. They both died within an hour. So I think it’s safe to say that when they turn belly up it’s too late for them.

The symptoms were this:

The rasboras would stop schooling and stay in one place, being lethargic. They would stop eating or even showing interest in food. Then they would start to tilt upward, and appear to be having trouble staying upright. Then they would turn belly-up, still swimming around, then coming to rest at the bottom. They would breathing very hard for a while before dying.

The two that survived were starting to show the symptoms of tilting and trying to stay upright, but when the treatment started they slowly got better, and a day later they started eating.

Now they are back in the tank, active and eating, though they are lonely, I will have to get more. First I want to monitor them to make sure they don’t get sick again before I get anymore fish. If they are fine within a few days then I’ll know that the disease is gone, as it kills alarmingly quickly.

So, through experience I figured out that melafix treats whatever disease this is, and does it pretty effectively.

If anyone knows what disease this is then please let me know. Also, if anyone is experiencing this disease but with another type of fish, then we’d know that it doesn’t affect only rasboras. To my knowledge, it doesn’t, as during the entire time I was dealing with it the other fish were fine.

I hope this post was informative and helped anyone who might be experiencing this problem.
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