I just brought home a baby betta yesterday from Petco and I have called the little one Squishy. He/she had stripes on his/her side when I brought him/her home and I know its a probable sign of stress. I would be stressed to if I were being sold that young! I checked on him/her today as I was feeding him/her and taking pictures back in the cup he/she was in at the store. The stripes are still there.
I have him in a small breeder net in a 10 gallon heated and filtered tank. The water is 78ish degrees (I can't really tell what the glass thermometer says exactly but 78 is my best guess). I'll go and check the water parameters in a minute.
I've been feeding Squishy New Life spectrum small fish formula pellets and today gave him/her a bit of a dried bloodworm (I felt guilty about throwing him back in the tub for pictures so I felt the need to give him a consolation gift).