いそがにじゃなかったです
磯蟹じゃなかったです
isoganijanakattadesu

Noun
Desu Copula

The polite, past negative form of いそがに

1. Wasn't a shore crab.; Wasn't an isogani.

Past/Perfective
Negative
Polite
Casual Register
Usually Written in Kana