Animal Crossing: City Folk Tips

Summer Fishing:
If you fish in the evening perhaps around 7pm from late July to early August you have a chance of finding some of the rarest fish in the sea.
Tom Nook will pay a pretty penny for these and they include:

Hammerhead - 8,000 Bells
Napoleanfish - 10,000 Bells
Red Snapper - 3,000 Bells
Shark - 15,000 Bells