My fish has been acting weird latly he has been laying down at the bottom of the tank, and swimming kinda weird. but sometimes he will swim around. When its time for him to eat he nearly jumps out of the tank before i can give him his food He has also been getting a black strip at the end of all his fins about a quarter of an inch in. i have had him for about a month and a half what wrong with him???? and why are his fins turning colors???