I can't figure out what's wrong with my P-Bass. I was fine, then all of a sudden it's laying on the bottom and breathing short and quick, his gill plates aren't moving, just his mouth, there is no bodily damage or fungus on the outside so it has to be something internaly. His diet has been just swordtails. He's been like this for 3 days now, and now he is starting to lay up side down. Anyone know what's wrong or if i can still save him he's about 7 inches now, i've had him since he was 3 inches. 

imua!!!