Butterfly fish

The Butterfly Fish (formatted as the Butterflyfish in ) is a saltwater fish in the introduced in. It can be found all day from mid spring to early fall.

In
Upon donating the Butterfly Fish to the museum, Blathers will say;

It can be found in the back tank with the other sea fish.

In
Upon donation to the museum, the information board in front of the tank that houses the Butterfly fish says:

Fishing Tourney
During a Fishing Tourney, when given a Butterfly Fish, Chip will say the following dialogue.

Real-world information
This butterfly fish is the oriental butterflyfish (Chaetodon auripes). There are many species of butterfly fish, some of which bear a resemblance to the barred knifejaw.