I have a freshwater tank with four Australian Rainbowfish (and some corys and a pleco). Recently, one of the rainbows has had trouble swimming. He can swim with the group, but normally ends up retreating to a place where a plant is near a wall, so he can sort of balance himself between them.
In all cases, his head points upward somewhat. When he's in that resting place, he is more than 45 degrees from horizontal. His pectoral fins and tail are constantly moving to help him remain afloat. When he rests those, he begins to sink.
I don't see anything physically wrong, and the other rainbows seem OK. I did notice the temp was a little high (83), so I turned down the heater.
I've read descriptions of swim bladder maladies, and this doesn't seem to fit. He's not darting around or flipping over or anything... just struggling to stay afloat.
Any ideas what this might be and what I can do?
Thanks.
In all cases, his head points upward somewhat. When he's in that resting place, he is more than 45 degrees from horizontal. His pectoral fins and tail are constantly moving to help him remain afloat. When he rests those, he begins to sink.
I don't see anything physically wrong, and the other rainbows seem OK. I did notice the temp was a little high (83), so I turned down the heater.
I've read descriptions of swim bladder maladies, and this doesn't seem to fit. He's not darting around or flipping over or anything... just struggling to stay afloat.
Any ideas what this might be and what I can do?
Thanks.