あぶらそこもつじゃなかったです
脂底鯥じゃなかったです
aburasokomotsujanakattadesu

Noun
Desu Copula

The polite, past negative form of あぶらそこむつ

1. Wasn't fatty tuna.; Wasn't red tuna.

Past/Perfective
Negative
Polite
Casual Register
Usually Written in Kana