recently i have lost a baby red tiger motaguense and a couple small ntt dats in the same manner...they start to breath hard, get really reclusive and stop eating. Then they died with their mouths open. And now my 4inch sveni pike is acting in the same manner, his mouth is open and his lips almost look inflamed. could this be gill flukes? all the other fish are perfectly healthy showing no signs of sickness and eating very well...any ideas?? water params are 7.2 ph ammonia-0