Strange Millennium Rainbow Behavior

  1. Annandgoldfish

    Annandgoldfish Initiate Member

    Have had this male millennium rainbow for about a month now and he randomly started to stay on the left side of the aquarium, ignoring the food that I'm putting in. I believe this only started today but usually all the rainbows come close to the right side of the aquarium when I'm near because they know that they're about to be fed (I always feed on the right side because the filter is on the left). I tried to put food on the left side but he didn't eat and looked like he freaked out when all the other fish came for the food.
    He seems fine but he acts more fidgety/scared when I'm near.
    This male is my largest and most dominant of the rainbows. Is he defending eggs? I saw him the other flashing wildly with the lights off. But I'm not sure if they even defend their eggs. (Not trying to breed them.)
     




  2. NavigatorBlack

    NavigatorBlack Fishlore VIP Member

    Try a 40% water change.
     




  3. OP
    OP
    Annandgoldfish

    Annandgoldfish Initiate Member

    Just tried it. Not expecting things to be instant, but no progress so far. Also observed him more and didn't spot any external infection. Thinking it's an internal parasite.
     
  4. RobM

    RobM Member Member

    Rainbows do not guard their eggs.

    If you suspect internal parasites you might want to setup a hospital tank and treat with PraziPro or Metroplex. @Sarcasm Included is better with diagnoses than me so hopefully he will see this.
     
  5. Sarcasm Included

    Sarcasm Included Well Known Member Member

    He looks healthy in the pictures and you haven't described any symptoms to indicate that he has parasites. If he starts getting thinner than that would be a time to consider parasites, but unless you have introduced a new fish/ plant to the tank in the last couple weeks it won't be parasites.

    Try feeding brine shrimp or blood worms frozen or live, to entice him over. First shoot some in your normal location with a turkey baster, if he doesn't come over shoot some in the middle of the tank. If that draws him over, feed every 2-3 days to get him in the habit of quick eating. I have an old Millennial that is skittish when I get around but aggressive with the other rainbows, so the behavior is not that unusual. You could also try breeding him, I might even buy eggs off you ;)
     
  6. Sarcasm Included

    Sarcasm Included Well Known Member Member

    He looks healthy in the pictures and you haven't described any symptoms to indicate that he has parasites. If he starts getting thinner than that would be a time to consider parasites, but unless you have introduced a new fish/ plant to the tank in the last couple weeks it won't be parasites.

    Try feeding brine shrimp or blood worms frozen or live, to entice him over. First shoot some in your normal location with a turkey baster, if he doesn't come over shoot some in the middle of the tank. If that draws him over, feed every 2-3 days to get him in the habit of quick eating. I have an old Millennial that is skittish when I get around but aggressive with the other rainbows, so the behavior is not that unusual. You could also try breeding him, I might even buy eggs off you ;)
     
  7. OP
    OP
    Annandgoldfish

    Annandgoldfish Initiate Member

    What I find weird is that he was not always skittish. He just started to be the other day and takes a much harder time noticing when it's feeding time and rejects the food when he notices them (If he does not spit flakes out, he would just swim through them like they're not there). I did find last night though that he would eat the emerald entree frozen food like crazy. I guess he was starving. But he still rejects flakes. Thanks for the advice. I will try it.
     
  8. OP
    OP
    Annandgoldfish

    Annandgoldfish Initiate Member

    c737eef93fc59487c8f1aa042d48ac01.jpg
    Late update but my fish went just about back to normal within just a few days of feeding more frozen foods. Here's a good photo of him flashing (he is the one below.)
     
  9. Sarcasm Included

    Sarcasm Included Well Known Member Member

    Glad to hear he is back in the game!