Fish

Largemouth Bass: 33 Simoleons

Jumbo Largemouth bass: 61 Simoleons

Catfish: 49 Simoleons

Rainbow Trout: 87 Simoleons

Jumbo Catfish: 124 Simoleons

Jumbo Rainbow Trout: 221 Simoleons

Golden Trout: 518 Simoleons

Basically every pond in Sunset Valley has fish; you know this by looking in the water, and finding objects that are moving. Sims with level 2 fishing skill can inspect water, and a warning will come up telling you what fish are in there. Most are unknown if you're not a highly skilled fisherman. If you read more books and fish a lot, you will be able to identify these "unknown fish".

Fun things you can find in the water besides fish are:

Mood Lite Candle, Death Flower, Bubble Bath, Rubber Ducky, Laptop, Birthday Cake, Guitar, Money Tree Seeds, Flame Fruit, Mysterious Mr. Gnome (There are actually different types of Gnomes. All I know is that there is a sleeping Gnome as well).