Sterbai cory swimming nonstop, breathing heavy

  • #1
Please help: SterbaI Cory paralysis, twitching, "seizures"

Hello, I'm posting on this forum because one of my cories has had a rapid decline in health. I've posted on several sites and have gotten very little advice or none at all. I'm trying to be as detailed as possible with pictures and videos as well because I want to document this sickness. I have not seen many topics about it, maybe a few threads, but they never reach a conclusion. I am aware it isn't easy diagnosing fish and he will probably die, but I figure I might as well make his death somewhat meaningful or get some information.

Basically, he has lost function in his ventral fins and can't swim normally. He has bouts of twitching. Some say it could be poisoning of some sort or TB (curving spine) I've read of a similar cases on a forum with no conclusion and it seemed to happen to several of his cories, one after the other. Could this be contagious? Should I quarantine him again?

1. Water parameters
Temperature range. 76-79
pH: 7.6
Ammonia, Nitrate, Nitrite: 0, 0, 0
Water change frequency: Once a week, about 60%

2. Tank set up
a) Size. 10 gal
b) Substrate: Sand
c) Filtration: Tetra Whisper Filter
d) Furnishings: Some fake plants, a hideout made of slate
e) Other tank mates: two other sterbaI cories and a betta
f) How long has it been set-up? 10 months

3. Symptoms / Problem description

Summary: Sudden change in behavior. Swam rapidly into side of tank (abnormally, not normal cory behavior swimming). Lost function of ventral and pectoral fins and thus cannot surface for air or turn with ease. Spine curves sometimes when he is still, but he straightens it. Darkened skin. Twitching.

UPDATE 10/31/2014

No change.



I have observed that he cannot seem to use his bottom fins. He can't lift his body up with his ventral fins, which makes it difficult for him to feed. He has a hard time turning because he cannot move his pectoral fins very well, if at all. He scoots across the ground, lying flat on his belly. He does eat food, but cannot access it well because of the above problems. I don't think he can surface for air. The barbs of his pectoral fins seem grayish and faded, instead of bright beige like his tank mates. He twitches strangely every few seconds, but will have bouts where there is no twitching. Slightly darker skin tone.


I don't know the gender...

Sudden onset of erratic swimming. I know cories like to swim against the glass, but this is different. It's expending all its energy swimming as fast as it can in the corner and actually made a crater in the sand from swimming so hard. It's twitching here and there when it stays still. I thought it was going to explode from using so much energy. Didn't think it'd make it until morning. I thought it may be swim bladder, but I'm not so sure. It isn't turning upside down, but instead just swims in a straight line, always staying upright.

Seems to have difficulty changing direction or going up for air. Does not seem interested in food because it is too busy swimming fast against a corner and breathing heavily. It was fine 10/27/2014 when I went to clean the tank. It was swimming with its buddies and did not appear to be stressed. Mere hours later, it was swimming like crazy and breathing heavily. I had noticed rapid breathing for the past couple days. Its barbels are very short/gone, but its been that way for months. It didn't seem to affect it in any way. It has been staying away from the other two here and there. I thought maybe its belly was a bit swollen, but I cannot say for certain. Reddish tint on gills and belly, don't know if that's normal.

4. Action taken (if any)

Update: I have since returned him to the main tank. He has been fed and an air pump added. Did a 50% water change and vacuumed.


I moved him to a small tub with tank water. I was concerned it might hurt itself or its tank mates. I was uncertain what to do about a heater, I know it's bad to let them sit in a tank without a heater when that is what they are used to. I have a small heater meant for a 5-10g so I was unsure if it was safe to put in the container. It was very late at night and I stood up trying to find an answer to what might be wrong, but it is very hard to diagnose a fish. Nothing really seems to fit. Some mention the possibility of poison from their barbs, but I figured he'd be dead by now and his breathing rapid, not slow. Could be parasites. I don't know. I've been treating the tank with kanaplex because my betta is a fin biter and I wanted to make sure he didn't have/get an infection. I added the last dose into the tank when I cleaned the water.

I've put six doses into the tank so far, spaced out as instructed, and waited about a week between each 3 round course so it didn't kill my bb. I figured it might help its barbels too because I read it might be from infection and I think I saw a little improvement, but not much. I put a pea into the tank after deshelling, boiling and crushing it because there was nothing else I could do and I figured if he had SBD it might help. Admittedly, I haven't been as diligent with cleaning the tank of leftover food because I've been working on a lot of projects and I feel really bad about that. The nitrates reached 50 ppm at one point, but I have since cleaned it twice or thrice. That's all I can think of that might have caused it.

5. Medications used (if any)

A pea

Food: Omega one shrimp pellets and hikarI disc

His tank mates are acting normal with no signs of stress. They both have long barbels and swim together. Right now he is staying still and twitching here and there. I assume he is exhausted from all the swimming. I don't know what to do. I feel helpless. I'm not expecting any miracles and he probably will die, but I'm hoping someone might know something...

I have pictures and a short video of his behavior. Unfortunately, it doesn't exhibit the same vigor and urgency that he had last night, but you can see something is not right. Sorry if the frontal photo is distorted, but he just sits in a corner and the container makes it look funny. Should I put the heater in the small container? I don't want to cook him. I had plants in there but they seems to be impeding his ability to swim to the surface because he'd get stuck, so I took them out.

Thanks in advance.

  • #2
I don't see anything wrong with it. If your params are fine then I shouldn't worry.

My cories swim nonstop too.

On a different note: A 20 gallon is the minimum requirement for Sterbais because how much they love to swim.

  • #3
I've had multiple catfish who do that, my peppered cory swims up and down the side of the tank constantly sometimes, and I had another peppered catfish who use to do exactly what your describing. It usually doesn't last though.
  • Thread Starter
  • #4
Thanks for the replies. When I view the videos, it doesn't seem to express how furiously he was swimming last night and early this morning. I've never seen that kind of twitching of the body or vigorous swimming before which is why I was concerned. He was struggling to get up for air because he kept swimming toward the glass. However, if you guys feel he more than likely will pull through I will put him back in the tank. He is acclimating in his small container in the bigger tank. He is just sitting there right now, so I hope he will be okay. I know cories need more space, but we bought the tank kinda on a whI'm 10 months ago. I plan to upgrade in the future. I don't mean to dismiss the space, I know it can be annoying when people do that, but I'm doing my best for the time being. I regret buying a small tank.
  • Thread Starter
  • #5
I hate to "bump" this post, but his condition has not improved. There is definitely something very wrong. Please review my top post for new information and video.
  • #6
I lost all my Habrosus showing the same problems.
Still think it's a kind of poissoning (chloride, chloramine, ammonia, nitrite)
All these can cause they'll partly paralize, swim in a strange way, heavily breeding.
Does it rol over now and then or lays on it's side ? Sorry I can't really help.


  • Thread Starter
  • #7
It's possible. Just a bit strange that it happened after cleaning the tank. He does not lean on his side or roll over. The video I posted is about the only thing he does:

Did all of your fish act this way at the same time or was it one after the other?
  • Thread Starter
  • #8
Another one of my cories is starting to show symptoms. When he sits still his head starts floating upward like he has no balance and his spine is starting to go inward, not severely, it's very subtle. His upper fin is also going off to the side. I'm noticing a slight redness in the "armpits". I don't know what to do now. My fish are all gonna die.
  • #9
Are you sure she's not just laying eggs? My SterbaI cories do that all the time. With eggs being left behind on the glass and everywhere. They don't last long since my other fish eat the eggs almost immediately. Due to the color of your substrate I can't see if she's leaving anything behind.
  • Thread Starter
  • #10
I thought it might be spawning at first, but it has been going on for days. I don't see any eggs. One of my cories is already really sick, can't swim to the surface or move its pectoral fins. This new cory is starting to bend its spine and there is redness around the barbels.


  • #11
The only thing I can think of is some sort of contagious sickness, if they are all showing the same symptoms. It could definitely be some sort of poisoning, I'm guessing you have been doing tests, but maybe take a sample of tank water into your LFS and have them test it to double check. While your there you could also explain what is going on and see if they maybe know what could be going on.
Even if you are doing water changes, there could be chemicals in your water. Heck, while your at the LFS take a sample of your tap water in too.
It kinda sounds like swim bladder problems though, not being able to swim correctly and laying on their sides, but it seems like your treating them for that and it isn't working. I'll try to help however I can.
  • #12
One thing I noticed with your water parameters is that nitrate is zero. There should be some at least. Could be new tank syndrome or an incomplete cycle. You can shoot for a bigger filter with lots more bio media.
  • #13
One thing I noticed with your water parameters is that nitrate is zero. There should be some at least. Could be new tank syndrome or an incomplete cycle. You can shoot for a bigger filter with lots more bio media.

I agree. You said it started after a cleaning. What exactly did you clean? It is possible to kicked off a new cycle.

Similar Aquarium Threads



Top Bottom