どくでわありませんでした
毒鱓ではありませんでした
doku dewārimasendeshita

Noun
Desu Copula

The polite, past negative form of どくうつぼ

1. Was not poisonous.; Was not a pufferfish.

Past/Perfective
Negative
Polite
Formal Register
Usually Written in Kana