how to give animation to images?

how to give more effects to image, i have a fish image, that is moving around the JFrame, and what i want also animation in fins of fish, how can i do this??
here is my code:-

just a thought only:

if you understand how cartoons are animated i.e. lots of drawings each drawn a little differently,
then shown in quick succession so the drawings appear to have movement, maybe if you can get
a slideshow (?) of images of a fish swimmming, then, as you move the fish position you also change
the image to the next one in the slideshow.