white cloud: not eating, floating to surface with mouth

Question
hi my son got one white cloud fish, read they needed a group of 5 socially, so
that same day, we went to the pet store, picked up a 2 gallon tank and 4
more white cloud fish. they all went into the tank together they've been doing
well until yesterday: noticed the one from the school isn't doing well. he
didn't eat at all, when all others were having a feeding frenzy.  we have 3
females, two of whom of pregnant, and they seem oddly jumpy and
aggressive (maybe babies are coming) about food, etc. i wondered if they had
somehow harassed the male from school (he's also slightly smaller).
the most worrisome thing is that his body is tipped up, as if he's trying to get
air, and he's always at the surface.  can you tell me if there is anything i can
do?  i noticed he was staying away from all the other fish - not usual
behavior, so i took him out and put him in a separate cup to make sure he's
not attacked (I noticed when it was near food, one of the female fish shot up
to where it was to take the food).  is there anything i can do for that fish,
other than isolating it for a time?  it's just floating, not really swimming; and
when the filter is turned on, it seems unable to resist the flow of water.
please help.

Answer
Hi Mari
Do you have a test kit to test for ammonia, nitrites, and nitrates?  If so, what are those reading?

I was reading on a site, they had some users post some comments about the fish.  It seems they sometimes have a tendency to be aggressive or territorial to other fish and sometimes their own species.  Other times, they seem to get along great.  So, for the sickly fish, it's really hard to say exactly what the problem is.  It could be he was being picked on, which stressed him, it could be from poor water quality, it could be he was sick when you bought him and just the stress of moving him to your tank was enough to trigger it.  I think you're best bet is to keep him isolated, and keep the water quality good by doing frequent water changes.  Your tank is a tad small for that amount of fish.  My personal opinion, a betta is really the only fish suitable for that size of a tank, and really I think bettas should be in at least a 5 gallon.  Plus, if those females are pregnant like you think, you may be very very overstocked soon :)  

It's been my experience when fish start getting to the point of just floating around with the current, they don't last much longer.  Like I said, I would keep him separated, keep the water quality good, and wait and see if he starts improving.  You could try adding a product called PimaFix in with him.  It's a natural herbal remedy good for a lot of fungal and bacterial infections, but usually it works best when used at the first signs of a problem.  It won't hurt, and it's some good stuff to keep on hand.

Good luck and hope he does better!  Let me know if you have more questions.

Christy