HI everyone. I have a bristle nose pleco in my 75 gallon tank. Everything has been good for months and my water parameters are good. This evening I noticed my pleco racing around the tank following the four walls. He's been doing this for about 20 minutes. I've never seen him act like this before. I also have a zebra danio in the same tank that has been swimming on it's side for a couple of days but it is several years old. Any ideas?