Why does a Yuma gape?

[sugartooth]

I have 2 large Yumas, one low, one medium height on a 30" tank lit with T5's.

I've had them for a couple of weeks and they looked good until today.
I noticed the smaller one, down low in the tank is gaping and I can see all of the insides. It's also changed to a yellow color, from blue/green.
The larger one, in the middle of the tank, is starting to show a little bit of gaping, the mouth is closed, but is a long slit instead of round and is starting to open.

What can I do?

I dipped a test strip in there and Nitrates, Nitrites are 0.
pH looks 8.0
Alk looks in the 'ideal' range.

I know these strips are general, and until I can get my hands on proper tests, this is what I have so far.

Any advice appreciated.

[kiknchikn]

Try moving them under something that will shade them from the light.

[Azurel]

Sometime they will do that to expels waste and then...
In my experience once a Yuma starts to gape, that is a bad sign, everyone that I have had that done this(every color form including the desired pinks) all melted with a few weeks after. From what I could find out it is usually a bacterial infection. I have lost all of my Yumas this way and won't keep them any longer.

[sugartooth]

Thanks for the feedback. There is no treatment for this? The gape has actually gotten really big, dime size, and I can clearly see the insides (looks like a mess of yarn)

If it's a bacterial infection, does that mean it will spread to all of them?

[ntfish]

It sounds like they will start "melting away" within a few days. The only recourse I can possibly think of at this stage is to cut them off of the rock, leaving the pedal disc behind. The pedal disc or "foot" may recover and grow a new animal over time. If I get more yumas that start showing this behavior I am going to try some powerful antibiotics on them.

[sugartooth]

How do I cut the foot off without ripping apart the gape? It seems like if I cut it off, all the contents of the mouth will fall out.
Is this correct?

[ntfish]

It can be very difficult, especially since the yumas are probably flattened out right now. Use a razor blade to slice it off very close to the rock. Depending on how advanced their condition is, they might be too mushy to do much with.

[sugartooth]

This particular one has folded on itself, mouth still open. I will try and slice it tonight.
Thanks for the tip!