[midgetswife]

3 weeks ago, my husband and myself brought 2 black moors they have been getting on really good together and have had no problems till yesturday, after cleaning the tank 1 of the black moors have sort of dug a small hole and is continually just lying in this hole, its also gone from black to silver on its scales (which are not raised) and is getting extremly fat, is it pregnant or is there something more serious?

any advice really apreciated