Hey there! I'm not quite sure if this unhealthy or not but I couldn't find something like it on Google. So I've had this comet goldfish for about a year now, and it's usually the crazy fish of the tank. But lately it doesn't move around that much when I turn on my light and walk in, and instead it just swims in one spot. It's like it's shy an scared when me or my light goes on. I've done tests and discovered that when i shut all the lights off he is active and interested with its surroundings. It's in a 20 gallon tank (I know, too small, i'm working on it) with a Ryukin, a Blackmoor, and a small lionhead goldfish. I do frequent water changes due to the size of the tank. He's the same size as the big fish so I don't think he's getting beat up or anything. His main buddy is the baby lionhead (which is really starting to grow). They follow around and when one stops the other stops. I also found that the comet doesn't eat when i give the food, he only likes to bottom feed when in the dark or when i'm not around. The same sometimes goes for the lionhead. If any of you guys know what's up, I would really like to know.