I'm worried about sudden red spots on my fish's gills?

I have recently transported 2 fish and a Pleco from Texas to Oklahoma. It was a 12 hour drive. They have been swimming well since they got here. The problem is they won't eat and there is suddenly redspots around their gills. The Pleco seems perfectly fine. I know they must be stressed but what are the red spots and how can I get them to eat? It is a Zebra Danio and an orange fish that my aunt says was a tetra but i'm not quite sure. PLEASE HELP!!!