Territorial Problems after driftwood/new stock introduced?

Discussion in 'Freshwater Fish and Invertebrates' started by gschra11, Apr 11, 2012.

  1. gschra11New MemberMember

    Howdy, folks,

    So, I'm a bit befuddled. My tank has done well for months, with my stock of primarily rainbowfish maturing nicely. I added a piece of driftwood recently after soaking it for over a week and dumping out the bucket of water it had been sitting in twice a day.

    It was time for a water change, so that's when I added the wood, as well as two otocinclus, a golden angelfish and a female threadfin to complement my male threadfin which had been living in my tank for four months.

    A few days after adding the new stock and the driftwood, my male threadfin was torn to shreds. He was still alive, but barely, and didn't make it through the night. It looks as though the other fish simply niped all his fins clean off, whereas there was never any bullying in the tank prior. As I said, he had been in there for months.

    Would resetting all of the rocks and adding the driftwood cause my rainbows to get highly territorial? I've always heard (and practiced) shifting rocks and plants around in the tank when adding new fish so that old territories would be broken and new fish could be safely added.

    Just trying to get some opinions as to what might have gone wrong?

    Aquarium info is accurate and in my profile.

    Thanks for your opinions.

  2. GordinianWell Known MemberMember

    Well, I probably won't be of much help in this thread, just wanted to say... welcome to fishlore!

    I can take a guess, and say that it was probably the angelfish, as otos definitely aren't fin-nippers. Other than that, all I can say is that you were right to believe that moving the decor around would reduce aggression, so that is unlikely to be what caused the damage. I also don't think fin-nipping would happen over driftwood.

    What are your water parameters?
  3. Wendy LubianetskyWell Known MemberMember

    Actually, when you introduct new stock and rearrange the decor you are totally changing the status quo. Even if rearranging the territories reduces the aggression, there is still going to be aggression as the fish jockey for their new space. When I rearranged and added a fish to my Oscar tank, there was mild fighting over the new spots. Maybe that fish is a particulariy aggressive one and other passive and they were fighting for new territories. As fish get older, they get more aggressive and more dangerous. I could introduce fish into my Oscar tank a year ago, but I couldn't even consider it now because the fish have matured and their aggressive and territorial nature would not allow it. They would definately kill a fish whether I rearranged the decor or not.

    I am sorry you lost a fish. Sometimes there is no way to prejudge how fish are going to react to something. When you introduce a new fish, you really have to watch to see how everyone is reacting. Sometimes they will settle back down into a "routine" and other times you end up removing the fish before it does get killed.

    I hope this helped a little. Wendy
  4. gschra11New MemberMember


    Water Parameters are in my profile link under aquarium #1. Off the top of my head I think they are 0/0/8.0/20 with 79.5°F water.
  5. ryanrModeratorModerator Member

    Sorry for the fish losses :;hug2

    I agree with the above, and would probably point the finger at the angel (they are cichlids after all).

    I've actually always left my decor as it is when introducing new fish.

    My reasons are related to territories. And as Wendy described, by re-arranging everything it kind of resets the game board. My thought has always been that a new fish, even an aggressive/territorial one, won't try and setup home in an already established territory. Kind of like "someones already here, I'll try somewhere else"

    That's my approach anyway - doesn't mean it'll stop the aggression, but I've had success with this method.

    Also worth considering is tall plants (real or fake), I haven't kept angels, but I read a lot of advice suggesting the use of tall plants to help break the line of sight.

    I would look at changing decor if after introducing it was still a problem.
  6. jbdubValued MemberMember

    Yeah i'm with the Angelfish theory. I had an angel kill two fish before I could rehome him. Have you got a divider you could use?
    Alternatively(if you have the time) watch them for a pronlonged period of time and you may see the aggressive fish acting out. That's how I figured it was the Angel, at night time and very early in the morning he was doing all the damage!
  7. pirahnah3Fishlore VIPMember

    When using the tall plant method try to stagger them in the tank to create a pathway that the fish can swim thru but something they can't see thru i.e. make it so that there is an opening to the front and then to the back a bit away from it, that way they can't see the other directly.
  8. gschra11New MemberMember


    Thanks for the advice. I have plants that are growing in the tank but are not of a size that really breaks line of sight, at least not yet. Whatever it was that went after the male took a chunk out of the female, too. (She is, of course, much smaller) I've since gotten a new male and put the male and female inside of a breeder isolation tank so that the female could heal up a bit and I could make sure the male wouldn't get eaten up. I'll release them this weekend and see if I can find the culprit. Of course, maybe since the decor has sat for a while the other fish will be less aggressive as ryanr suggests.
  9. allaboutfishWell Known MemberMember

    obviously if they are attacking only the threadfins, the fish arent compatible.

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