24th of Av, 5770
Besides shellfish (shrimps, oysters, lobsters, etc) what other ‘popular’ fish are non Kosher and why?
Examples of non-kosher fish:
Catfish – it lacks scales entirely. Interesting for the kosher consumer to note, catfish (not Kosher!) is reported to have a similar taste to the increasingly popular tilapia (kosher!) Catfish and tilapia fillets look almost identical, though catfish is notably cheaper. It is therefore quite possible that an unscrupulous fish retailer might switch the two!
Basa or Tra (also called “China sole”) – (family Pangasiidae) are currently the subject of both nomenclature debates and antidumping litigation. Vietnamese importers were marketing them as catfish, to which they are nearly identical. Whether they are in fact catfish or not, they are not kosher.
Examples of NON-Kosher fish with ‘scales’
Swordfish has scales but they are embedded to such an extent that it is impossible to remove them without making a hole or that its scales would fall off during its development, rendering swordfish as non-kosher.
Sturgeon definitely has scales, but it is not kosher. Its scales are classified as “ganoid”, which means that they are covered with ganoin (similar in texture to fingernails) and cannot be removed without tearing the skin.
Burbot has cycloid scales (one of the types often referred to as “always kosher” ) yet because they are embedded, this fish is not kosher.
Sand lances may have tiny scales, but since they are not visible, this fish is not kosher.
Adapted from www.kashrut.org and www.ou.org