I'm very concerned about my albino polypterus palmas, I've had her for 3 or 4 years now and until today she has never shown this behaviour before. She is consistently charging round the tank swimming up an down in erratic patterns one time she was half in and half out of the water. Another one of my bichirs was exhibiting this same behaviour but has since stopped after I fed them. She has been doing this almost all day she only stopped once for about half an hour to an hour I have no idea what this could be other than stress but I don't know what's causing her to stress out for so long. I'm going to do a partial water change on the tank. Please help!