She's been quiet for two days now..  And when I fed them this evening....   She literally exploded!  What in the world??

This looks like something right out of the aliens movies..

She was hiding at the top of the tank, under the filter.  I opened the cover and fed the rest of them - no sign of trouble there - and after they'd finished eating, I looked for her.  No sign.  I fed some others and came back. Still no sign of her.  At this point I started to wonder if she'd jumped out.  I had a look around, and sure enough, there she was.

I didn't see her jump out.  I'm sure she didn't jump out before feeding.  When she's sitting on the paper for the photo, it looks like she was about to rupture from the side too...

Has anybody come across anything like this before?  Its just too damn bizzare!

And no, she has had ZERO contact with the tank, fish, or any equipment that the previous ruptured fish was in contact with.

Background:  We got this group from a local petsmart.  My wife desperately wanted this one.  We knew we were taking a chance because they'd lost just over half of their delivery of guppies from the day before.  Hence, we were extremely careful about quarantine.  I had a tank all ready.  I put an already cycled filter on, some gravel in, and the ammonia/nitrite stayed at zero for the last 6 days.

We also got another young male from the same place two weeks ago.  It got out of quarantine yesterday.  Except.. I've just noticed that it isn't eating.  At all.  It seems to be trying to eat, but just spits it right back out again.  I just pulled it back out and have it isolated too. It hasn't got any other signs of problems except for being rather skinny and not eating.  It was very active when we got it though.  Its stomach curves inwards rather than the usual slight outward bulge.  When you look at it from behind, it seems as though its gill covers stick out to the sides a little more than normal.  It seems to have faded its colour a bit too.  There is no sign of fin rot or damage.  No externally visible signs of trouble (that I recognize) at all.

Oh man, I'm cursed.  Alien-infested exploding guppies committing suicide, hunger strikes, Yet Another 25 fry today..  What next?

Seriously though.. Does anybody have any idea what the heck happened?  Should I be worried about the other 6 fish in the quarantine tank she was in?  (They are not showing the slightest sign of trouble)  Should I look inside her to see if there are obvious parasites?