Salmon

The Salmon is an fish that can be found in the river. It appears all day in September. When selling it to Re-Tail, the player will earn 700 Bells.

Location
The Salmon is found in the river.

The Museum
The Salmon can be donated to the museum. Upon doing so, the following text is given by Blathers:

"Salmon are popular migratory fish that are born in rivers, migrate to oceans, and return in four years. In Japan, flavored salmon eggs are a very popular dish called ikura, but it hasn't caught on in the US. In rare cases, salmon will only stay in the ocean for one or two years before coming back. These fish are known as "phantom salmon" since they're so hard to find in the wild. Their characteristic pink color comes from the shrimp and krill they get in their diet. If they ate differently, their flesh would be white. Salmon only spawn at the bottom of the waterfall where the lake meets the ocean."

Quote
Upon catching the fish, the player will say the following:

"I caught a salmon! Oh, that's slammin'!"