Molly behavior question

[thartley]

Can a fish knock itself unconscious and if so, does this possibly indicate a problem (besides stupidity )?

My daughter recently got a couple of Mollies to add to her community tank. It seems that one of the Mollies likes to swim up and down along the side of the tank and I think it bumps into the side. We thought it was looking at its reflection.

Today my daughter found the fish upside down on the bottom of the tank. We thought it was dead so I told her to remove it. Before she got back with the net, I observed that is was breathing - she didn't notice if it was breathing or not when she came to get me to ask me what to do. I moved my hand next to the glass and the fish started squirming, but it couldn't seem to upright itself. A minute or two later when she tried to net the fish, it started swimming around and was actually a bit of a challenge to catch. We have isolated it in a glass of tank water. I noticed that the front of the fish's mouth area is kind of reddish and beat up looking now (the fish is an all white fish).

I just checked it again in the glass and it is having a hard time staying upright. My daughter agrees that its 'nose' is pretty banged up. She says it looks like it is crooked now too - bent to one side.

It is a 12 [acronym:3a21d0a20b="Gallon"]gal[/acronym:3a21d0a20b] planted tank - all livebearers - 10 guppies of various ages, two platies, and two mollies.

I'm not as worried about that fish as I am about about the rest of the tank.

So, what do you think, is this just a low IQ fish or a contagious health problem?

Thanks,

Tom

[TankGirl]

I would say this is an ill fish, and it is good that it is separated. Several things could cause it to swim erratically, like gill flukes or parasites that cause it to "flash" or scratch against things, or it could be a swim bladder problem.

Anytime a fish behaves in a bizarre way I always remove it and treat it separately - fish do have some personality quirks but if you notice unusual behavior it is almost always due to some kind of a problem.