Herabuna

The herabuna is a freshwater fish in the introduced in. It is unique in that in only appears in, making it the only Japan-exclusive fish in the series. The herabuna is also the only fish to appear in but not in.

In, it is replaced with the statistically similar brook trout. The herabuna is similar in size and design to the crucian carp, but it differs in that it is taller and has a more prominently arched back.

Donating to the museum
When a herabuna is donated, Blathers will say this:

Real-world information
The Japanese white crucian carp, as it is known in America, is a freshwater dwelling fish that originated in Japan. Now spread through most of Asia, it was thought to be a species of wild goldfish.

In Japan, this fish is more commonly known as the Gengoro-buna (ゲンゴロウブナ) in a general context, and is considered an Endangered species. It's called Hera-buna (ヘラブナ) when referring to a cultivated variant, bigger in size, and mainly used in sports fishing as a substitute for another type of carp; the Nigoro-buna (ニゴロブナ).

The 7th edition for the Japanese dictionary "Kōjien", explains that the origin of this species name comes from "the fish caught by the Katada Fisherman Gengorō, which he offered as a tribute to the then-lord of the Castle Azuchi (Oda Nobunaga)".

The "buna" in its name, as with other similarly named carps, comes from the word "funa" (フナ), used to refer to the Carassius genus of carps.