Cories Flashing? Help

  1. simplepleasure Initiate Member

    I have three pygmy cories that I've bought in the last week. The last couple days I have noticed that at least a couple of them (not sure if it's all three, two of them are hard to tell apart) are flashing a little. I've never seen this before (at first I thought it was a funny idiosyncrasy until I Googled it). My other fish seem normal. I see no other external signs of a problem, and the cories are acting fine (as far as I know, obviously my experience with them is limited).

    I read that a pH change can cause flashing; my pH is steady at 8.2, but the LFS pH might be lower if they use RO water. Ammonia, nitrates, and nitrites are 0. Should I treat for something like skin flukes just in case? No experience with this at all.
     
  2. Aquaphobia Fishlore Legend Member

    How long has your tank been running? What kind of substrate do you have? Have you changed or cleaned your filter at all?
     

  3. Floundering_Around Well Known Member Member

    Have you been using aquarium salt in your water? Cories are more sensitive to salt since they don't have scales to protect themselves
     
  4. simplepleasure Initiate Member

    Tank has been running about two months. Substrate is a mostly smooth gravel (will use sand in larger tank that I am getting for the cories). Filter remains unchanged.

    I have not used any salt.
     

  5. BeanFish Well Known Member Member

    I used to see ocasional flashing in my pygmaeus and I think it was caused by flukes. If you have a lot of detritus hanging around that can also cause them to flash, has also happened to me, I suspect it has to do with the detritus getting caught in the gills and irritating them.
     

  6. EJ_Fresh Well Known Member Member

    Keep a close eye on them. If the flashing increases or if you see any other signs of illness (changes in eating habits, reduced energy level, clamped fins, labored/rapid breathing etc.), it may be worth treating. When I first started my tank, I had a batch of cories that ended up being ill and the first sign was flashing. I think it was flukes or another type of parasite. I lost a couple of the cories, but then had good results treating with Seachem Paraguard. I would recommend getting some to have on hand in case you need it.
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  7. simplepleasure Initiate Member

    Thanks. They sometimes have their fins down when they are lying down; is that not normal? Would that be fin clamping? I'm not sure I've had them long enough to be able to determine whether their breathing rate is fast, but I will keep an eye out. Otherwise they seem to by happily settling in and behaving normally.

    Edited to add: When is it normal for them to have their fins pulled in a bit? One cory is swimming around with top and bottom fins pulled in somewhat. Others seem to consistently have them in when they are lying on the substrate. (I assume some fin movement is normal; I'm just trying to figure out what is normal versus abnormal.) Thanks.
     

  8. EJ_Fresh Well Known Member Member

    I know what you mean. It can be tough to figure out what is normal when the fish are still new to you. As far as the fins, my cories default position is having their dorsal fins positioned upright and their other fins mostly out to the side. It's the same whether they are swimming or resting. If they swim super fast, or are going through the filter current, their dorsal fin may go down briefly, but then it pops right back up. When mine were ill, their fins were held close to their bodies most of the time. I will include a picture of what mine look like in the "normal" position. Hope it helps.
    image.jpeg
     
  9. simplepleasure Initiate Member

    Thanks. I think I will try using the ParaGuard just in case. It does seem like something it a little odd, even though they are acting and eating okay.
    I think this little tank will become my QT once I get a bigger one!