魚

Chondrichthyes (class comprising cartilaginous fishes)

Osteichthyes (class comprising the bony fishes and sometimes their descendants, i.e. tetrapods)

Astronomy

Volans (constellation); the Flying Fish

clouded salamander (Hynobius nebulosus)

Japanese black salamander (Hynobius nigrescens)

gibberfish (Gibberichthys pumilus)

arctic char (Salvelinus alpinus)

arctic char (Salvelinus alpinus)

pebbled butterflyfish (Chaetodon multicinctus); multiband butterflyfish

fisherman bat (Noctilionidae spp.); bulldog bat

four large domesticated fishes (black carp, grass carp, bighead carp, and silver carp)

Queensland lungfish (Neoceratodus forsteri)

imitation that looks identical to the original; fake causing the original to lose value

miswriting a word; using the wrong kanji to write a word

fish in a pot about to be boiled; person who is blissfully unaware of deadly danger

miswriting a word; using the wrong kanji to write a word

Mahjong

win on the last discard of a round

Idiomatic expression

collateral damage; getting embroiled in someone else's dispute; having a fire spread to one's own house

Idiomatic expression

someone doomed to their fate; fish on the chopping board

From a rakugo story; used ironically to poke fun at someone who makes an ignorant statement with confidence

Pacific saury is only good if it's from Meguro

Idiomatic expression; Suru verb - special class

to miss a big chance; to miss out on a great opportunity; to let a big fish get away

Proverb

the biggest fish is always the one that got away

background character (in a manga, anime, etc.); unimportant (usu. nameless) character

Video games

mob (non-player character); easily defeated enemy character; minor enemy character

Organization name

Senzokugakuen'uozu Junior College