Today I woke up and seen that my weeksii bichir was looking very strange his head was in the sand and the tail was floating so I scooped him up with the net to see if he was ok and I let him go to see if he would swim and he just fell to the bottom of the tank and he is completely flat and rolled over to its back and doesn't even try to move but its still breathing I have no idea what wrong with him any ideas?