Aggression Among Commons

Discussion in 'Freshwater Beginners' started by Sync, Apr 24, 2017.

  1. SyncNew MemberMember

    I received 5 new commons to add to my 2 commons. After the weekend I noticed one of the fish was bloody and had torn fins and a new fish was hitting her side. I removed both of the original commons and don't know what to do.

  2. Bruxes and BubblesWell Known MemberMember

    How big is the pond? I assume we're talking about common goldfish - they can give chase and possibly be aggressive if they feel like they do not have enough space to call their own.

  3. SyncNew MemberMember

    I use a tank, and a very spacious one with 10 fish, including the 7 commons

    I can't say for sure, but I estimate the tank is 1 1/2 feet tall, 1 foot wide, and 4 feet across. The 3 other fish, not goldfish but silver and black and unknown to me, fit in just fine. As expected the 5 new common fish stick with each other but behind the building and plant.

    Last edited by a moderator: Apr 27, 2017
  4. FishFish221Well Known MemberMember

    Your tank size you described seem to be for a 45 gallon long, which is too small for 7 common goldfish to properly develop. This could be causing the aggression. For 7 common goldfish, they need more than 100 gallons.
  5. BeanFishWell Known MemberMember

    7 common goldfish probably need 1000 gallons.
  6. FishFish221Well Known MemberMember

    What are the other three fish that you have? If possible, can you include an photo of them.
  7. SyncNew MemberMember

  8. BeanFishWell Known MemberMember

    That is a black skirt tetra, they are schooling fish and I think they have a little bit of fame as nippers. They are also tropical fish so they need warmer water than goldfish.
    You have size issues and compatibility issues, goldfish should be kept with goldfish IMO (and maybe Plecos). Commons need ponds and as said, skirt tetras are schooling fish which means they need at least 6 of them to feel safe, and need warmer water.
    I would also fill your tank all the way up, you seem to have a lid, and all that space between the water and lid is just wasted space that you could fill with water so the environment is more stable.
    I would personally rehome the commons or get a pond for them. You can also just rehome the black skirt tetras but that wont solve the size issues.
  9. SyncNew MemberMember

    Their origins are more unknown since I received them as gifts in 2 separate bags of 1 and 2. Also, the 5 new commons were from my friend, since in a nearby public swimming pool, they stopped using chlorine and used fish instead which leaves 65 fish or so in a black container that probably holds 100 gallons so how come they aren't aggressive? They all look fine and treat each other kindly

    I couldn't get a good picture when I got Butterfly out of the tank in her torn state but here's a picture of her right now
    Last edited by a moderator: Apr 27, 2017
  10. BeanFishWell Known MemberMember

    This is all getting confusing, state species please. If 65 goldfish were in that 100 gallon pool, well, first of all, it is masively overstocked, secondly, I think they were goldfish right? Goldfish are not agressive, I dont think your goldfish are fighting, the 3 new fish that you added, are black skirt tetras and those more than likely are causing the trouble.
    I would not suggest you handling your fish like that, you are stressing him which is not good, specially for beaten up fish that need an strong inmune system.
    I would inmediatly separate those 3 fish from the goldfish.
  11. FishFish221Well Known MemberMember

    And I think the fish would need a filter as there does not seem to be one in the photo.
  12. SyncNew MemberMember

    My friend said they were comet goldfish apparently, and the black tetras fit in perfectly. So 5 comet fish, 2 commons and 3 black tetras, I believe. And the 65 fish knew each other since they were in a public swimming pool before moving into a big container
    Last edited: Apr 25, 2017
  13. FishFish221Well Known MemberMember

    Well, first of all, black skirt tetras cannot be healthily kept with goldfish and vice versa. Goldfish need temperatures of around 22 degrees celsius (71.6 F) and black skirt tetras need at least 24 celsius (75.2 F).

    Second of all, your fish tank is not large enough for the goldfish to grow and be healthy. Seven single tailed goldfish [Comets, Commons and Shubunkins] need at least a 6 feet long fish tank.

    Do you have a filter in your fish tank? There doesn't seem to be one in the photo.
  14. SyncNew MemberMember

    Yes, there is a filter
  15. _IceFyre_Well Known MemberMember

    Do you know which type by any chance?
  16. SyncNew MemberMember

    If you mean brand, no. It simply sucks up water and filters using stones before being poured back in.
  17. -Mak-Fishlore VIPMember

    You need to rehome the goldfish or get a pond, there is no other way to put it. It may seem spacious now but leaving your fish in there will stunt them - their organs will outgrow their body, not a fun way to go.

    The black skirt tetras need warmer water and a larger school to curb aggression.

    In addition, is your tank cycled?
    Do you have a test kit?
    Last edited: Apr 25, 2017
  18. SyncNew MemberMember

    All right then. I understand what has to happen but the tetras seem comfortable. They have been there for about a year and I never saw traces of aggressiveness. And I always find them alone and away from one another. Basically, contradicting what you guys said about the black skirt tetras. I can give back the comet fish or as my friend suggests, the one she believes is being aggressive but it would be easier to give them all back. And I have no idea if the tank is cycled and I don't have a test kit.

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