By: Halacha Yomit team of OU KOSHER
May I purchase a kosher fish from a non-kosher fish store?
Assuming you confirmed the fish was kosher (by seeing a scale removed or by recognition of the species of fish), the remaining concern would be the knives, board, and gloves with which it is handled. Assuming they are all washed properly, it is permitted to purchase the fish. If the fish was cut with a dirty, non-kosher knife, one would need to wash it and pass the sharp side of a knife over it (maavir alav chudo shel sakin) in order to remove the non-kosher residue (see Pitchei Teshuva 96:5, b’shem Teshuvot Chavot Yair 179).
For those interested in a more in-depth look at the halachot of fish, please contact Goldbergc@ou.org to inquire about the OU’s Fish Industry Manual.
what about warns??