I noticed today that one of my tetras eyes has turned black. I looked it over to see if there is anything else visably wrong with the fish, and as far as I can tell he looks fine. I watched him when I fed them, flakes, and he didn't eat. He's usually shy so I stepped back to see if that would change, but nothing. He seems to be staying at the top of the water as well as off to one side. I've had these fish for like 6 years, and I don't want them to be sick. Can you help? What do you think is going on?
Thank you.
Thank you.
