4 Cory Sterbai dead in 24 hours

Discussion in 'Corydoras' started by lukethegti, Jul 13, 2015.

  1. lukethegtiNew MemberMember

    Hi Guys,

    Bought 6 cory sterbai from my local shop yesterday and when I came home one was dead (one of those things).

    However, I have just got back from work today and another 3 have died. All have red blotches on the sides.

    My LFS was happy to give me a credit note for the single fish however, I feel I should take the other 3 dead fish back.

    can people please have a look at the photos to see what they think it could be.

    500l tank, tank was purchased second hand, and was cycled for over a year before hand, has been run empty for 10 days, all parameters are fine (LFS tested today, maybe slightly hard water).



    Attached Files:

  2. BornThisWayBettasFishlore VIPMember

    Welcome to Fish Lore!!!! Man, you live in the U.K. too? Some people have all the luck.......

    What did your LFS use to test the water?

    Can you give us the exact readings?

    What did you use to cycle your tank?

    I'm not sure if anything could've happened to your beneficial bacteria or your cycle in that short of time, you'll have to wait for more opinions.

  3. CoradeeModeratorModerator Member

    Sounds like a case of self poisoning if one died in the bag & others succumbed soon after, sterbai are one of the species more prone to self poisoning.
    Edit: another thought, it could also be red blotch disease  

    Last edited: Jul 13, 2015
  4. lukethegtiNew MemberMember

    Hi Guys,

    Thanks for your replies.

    In terms of the fish dying, non died in transport, just a few hours after going in the tank.

    The water was tested using a standard strip. I have just done another and the following came out:

    No3 10mgl
    No2 0.5mgl
    Cl2 0mgl

    Not sure what it could be! Potentially red blotch?


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  5. Dom90Fishlore VIPMember

  6. CoradeeModeratorModerator Member

    I must've misunderstood your first post, sounded like it had died in transit, if that's not the case then I'd go with it being more likely red blotch disease.
    Forgot to say Welcome to Fishlore :)
  7. lukethegtiNew MemberMember

    Usual, left them on the top of the tank for around 30mins slowly adding water from the tank.

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  8. lukethegtiNew MemberMember

    Thanks Coradee!

    Is there a way to be sure?

    Also I have 10 black neons in there, are they going to be ok? Ie how contagious is it?

    Would it have come on that quick? Nothing too obvious in the shop (although admittedly I didn't look out for it). One was dead in the tank though :S

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  9. CoradeeModeratorModerator Member

    Unfortunately there's no way to be 100% sure, keep a close eye on the remaining two & keep the water pristine.
    If it was red blotch then it shouldn't affect your other fish as it mostly affects catfish & other bottom dwellers
  10. CindiLFishlore LegendMember

    What is self poisoning? I have not heard of this before. When I first brought home my cories I lost a number of them with 24-48 hours after arriving home. My current 6 I've had for months now.
  11. CoradeeModeratorModerator Member

    Corys can give off a toxin when stressed & if it happens in the bag they can just keel over & die or die soon after they've gone into the tank.
    It's thought to be a defence mechanism from predators.
  12. lukethegtiNew MemberMember

    Potentially it could be that then.

    To be fair one did die within 6-8 hours and the others may have had a nibble.

    Would you say this is a stress / defence mechanism?

    I am thinking of asking the shop for my money back, am I entitled?

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  13. Dom90Fishlore VIPMember

    That would depend on what kind of guarantee the fish store gave when you bought the fish.
  14. lbonini1Well Known MemberMember

    You should get a liquid test kit such as the API Freshwater Master Test Kit, it's much more accurate than the strips.

    Also, if you're getting a NitrIte (NO2) reading on any sort of kit be it liquid or strips then that would be a cause for concern because your tank isn't cycled.

    I'd get a liquid kit to confirm your results and then do water changes with Seachem Prime or Amquel+...

    Good luck!
  15. alinkWell Known MemberMember

    Based on the strip test results, you are positive for NO2, which is Nitrite. I would then be concerned you may have ammonia, which would account for the red spots on the gills and the fast deaths in the tank. However, strip tests are not very accurate in getting precise numbers. Do yourself a favor and get an API Fresh Water Master Test Kit. It is a liquid test with vials and you follows the directions and it will give you a far more accurate test, plus you get over 800 tests for 30 some dollars (euros?) which is a lot cheaper in the long run compared to the strips.

    You said you acclimated them by slowly adding tank water to the bag. When you released the fish into your tank, did you dump the water from the bag in with them? If you did, that could bring a whole bunch of problems to your water that can effect any inhabitant in there. You should net the fish from the bag and then add the fish to the tank. You dont know what is in the fish stores water (diseases, contaminates, etc), and you dont want that in your water. If you didnt add the water, then good, you did the right thing.

    Finally, moving is stressful for the fish. Often times within the course of a week, they are caught from a breeders tank and put in a bag. Then they are shipped across the country (or world) to another distributor. This could be your LFS or a bigger distributor who will then ship them to the LFS. Then they are in a tank with fish that arent necessarily ideal companions and the water quality could be less than stellar. Then they are netted, bagged and transported to your house. That is a lot of stress for these fish, so sometimes they just dont make, or they pick something up along the way. This is why quarantine tanks are strongly recommended. The fish stores usually have a warranty on the fish for a period of time, but if those fish you buy from them today, bring something like ich into your tank, and then some of your other fish catch it and dont make it, they wont cover that. So its best to keep them isolated for 2-4 weeks after purchasing. In that time anything bad they have will appear and you can deal with it there without effecting your main tank.
  16. Dom90Fishlore VIPMember

    Like alink said, it might have been ammonia poisoning since there is a big red spot near the gills of the fish. Is your tank cycled? Did you check the numbers given by the LFS or just take their word for it?
  17. lukethegtiNew MemberMember

    Hi alink thanks for the advice.

    When I put the bag in the tank I didn't empty the water in there also. I haven't ever done this, as you say it can open a whole can of worms!

    I will have a look at the API master tests and maybe get one of those!

    In terms of the LFS they did the standard dip test strip, so I suppose neither of us are sure whether there is any ammonia.

    However, I have transferred 10 neon fish (on the day previous) and they seem fine.

    The tank was run for over 8 months prior to my owning and once it was set back up it has been empty for over a week. I do appreciate it may be coming out of a fish less cycle though.


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  18. Dom90Fishlore VIPMember

    If you only added the 10 neon tetras the previous day, you need to let the bacteria catch up to the new bioload before you add anymore fish. Usually give it a week to settle in.
  19. alinkWell Known MemberMember

    How long was the tank dry between the 8 months it was running and now? If it was more than a day or 2, any bacterial that has colonized is likely dead. Therefore you would be starting over with a brand new tank. Running the tank for a week will not bring it back, even if you use a bottled bacteria product. Cycling a tank takes anywhere from 2-4 weeks, and has been occasionally reported to take up to 6 weeks depending on method of cycling.

    If you just added 10 neon fish the day prior to adding these cories, that makes me think even more that you have ammonia. Lets assume your tank was cycled when you added the neons. At that point, your bacteria colony would have to multiply enough to process the extra waste produced by the neons. This takes anywhere from 3-10 days. Adding more fish the very next day, didnt provide enough time for the bacteria colony to catch up, which means there was likely ammonia in the water that was waiting to be processed and that could have led to the death of the cories. It is commonly advised to wait a week or 2 between batches of fish, and when you do, it should only be 5-6 at a time so you dont over load your bacteria.
  20. lukethegtiNew MemberMember


    The filter wasn't ever dry in the few days between the guy emptying the tank and me refilling it the old tank water was in there.

    I know not ideal and this was emptied and refilled once tank was ready to go.

    In terms of bioload, the tank has two filters on there (both for up to 500l) and surely with that plus the amount of water for the ammonia to dispurse it shouldn't be a problem?

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