Sea butterfly

The sea butterfly is a sea fish in the introduced in. During its availability from December to February, the sea butterfly is the only saltwater fish with a tiny shadow size.

In
In, the sea butterfly appears as a default item in Wade's house.

Donating to the museum
The sea butterfly can be donated to the museum by talking to Blathers. Below is what he says during the donation:

In
The sea butterfly is placed in the large sea tank in the aquatic display in the back room.

In
It occupies a large glass tube in the lower-right corner of the fish exhibition, with other small sea fish.

In
Upon donation, the information board outside the tank that houses the sea butterfly says:

In
When the sea butterfly is donated, six of them will appear in the northern room of the fish exhibit, in a tall tubular tank with a light blue crystal. It is one of the few fish which the museum will have multiple of upon its donation.

Fishing Tourney
During a Fishing Tourney, when given a sea butterfly, Chip will say the following dialogue.

Real-world information
The sea butterfly that appears in the series is specifically the Clione limacina, also known as the naked sea butterfly, sea angel, and common clione. They can be found in the cold waters of the Arctic Ocean, Antarctic Ocean and in the North Atlantic; mirrored, in-game, by their appearance during the winter months. They can grow up to 5 centimeters in length.