What is wrong with my crowntail betta fish?

[Ravenclaw Alumni]

He used to eat immediately when I fed him and would just stare at me if I tapped on the glass but now he ignores the food and if I tap on the glass he freaks out and zooms around the aquarium like he's being chased. He also spends all his time at the bottom of the aquarium and doesn't seem to want to move. He has a thermometer and the temperature is fine and there is nothing wrong with the air bubbles, either. Any ideas?

[BettaLu&Meg]

make sure the temp is at 76-80F it does make a diff. i have 10 adults and i bred my CT with a VT and i keep the fry at the same temp. check him for a white film and white spots on him, do u have a filter? he might be sick but i don't know from just this. usually if a betta is at the bottom of the tank he's sick. take a look at him and i'll be happy to help as much as i can and guide u to guidlines to helping out your lil guy! i love these guys like there my children so i def feel your concern!! my email if u cant get to me on this is Luis_megan21108@ yahoo. com