Goldie is CoCo

Goldie the fish is fast turning into looking like coco. Her head is turning black and the tips of her fins. I don't know why...its a bit sad. She has out lived all the other fish by two days. She is swimming around like a crazy fish and crashing herslef in to the side of the tank. I feel sorry for her. This is kinda like a science experiment. Servival of the fittest.