Is it okay to eat fish with an isopod parasite on it? I bought some frozen Hairtail fish (Chinese: 帶魚) and one of them had some kind of isopod on it. I already removed the bug and threw it out, but after some research it looks a lot like the image here: https://en.wikipedia.org/wiki/Cymothoidae
Is it still okay to cook and eat the fish?
I'd say no.
Conventional wisdom suggest that when in doubt, throw it.
Throw it away, go back to your fishmonger/store and tell them about that.
If that fails, do not buy from that brand (if there's any brands attached to your frozen fish)