ぬまかれいじゃなかったです
沼鰈じゃなかったです
numa kareijanakattadesu

Noun
Desu Copula

The polite, past negative form of ぬまがれい

1. Was not a flounder.; Was not in a swamp.

Past/Perfective
Negative
Polite
Casual Register
Usually Written in Kana