I found my Lap Bircher (7-8inches) on the rug in the spare bedroom where we I keep the extra aquariums, he was about 1 foot form the aquarium upside down and had red marks on his underside. I have an Australian aro in the same tank (about 4-5 inches) who appeared fine this morning. They are in the 10gal quarantine tank that is divided, and gets 2 to 3 water changes each week of 25-50%. Does the red on the underside signify anything?