Yes, you can crack a Cichlid. You can snap a Siamese Fighter. Annihilate an Angelfish? Without even breaking a sweat. Go ahead, bust a Bichir. Piece of cake.
Lambaste a Loach. Make mincemeat of a Minnow. Truncate a Tetra. Slice a Swordtail. Ruin a Rainbowfish.
Falling off a log, I tell ya.
But breaking Guppies? Hard to do.