Plate question


I bought a short tenacled plate and cabbage leather with zoos Friday afternoon. Before I could get them home I had an emergency. My son picked them up and put the bags in my tank. He left the lights on (260 pc). About 5 hours later I got home and put them on the bottom. The plate has shown no sign of life and looks bleached out. The leather looks so/so. Is there any hope for the plate?