Why Swordfish is Unclean

he juvenile swordfish has scales, although the adult does not.   Is this fish clean or unclean?

"This reply is based on several sources in halacha [the entire body of Jewish law and tradition, including the laws of the Bible, Talmud and oral law]. Most notably, extensive research by Rabbi Moshe Tendler, Chairman and Professor of the Biology Department at Yeshiva University, March, 1966.

"The halachic [status] of swordfish (xiphias gladius): it is a non-kosher fish. It has been presented to halachic giants of our generation such as Rabbi Moshe Feinstein and from previous generations such as Rabbi Itzel of Ponovitz, and they have all concluded that it is not kosher.

"The biblical term for scaled kosher fish is 'kaskeses.' Nachmanides comments in Leviticus XI:9 that based on Biblical and Talmudic sources this refers to a type of structure like the nail of a human which can be removed from the skin of the fish by hand or with a knife. But if it be affixed to the skin and not separated therefrom at all (i.e. no free margins), then the bearer of these 'scales' may not be eaten.

"Ichthyologists recognize four types of fish scale. The kosher variety of scales are cycloid (round) and ctenoid (comblike). The ganoid scale found on sturgeon, or the placoid scale of the shark are specifically excluded from the Biblical term kaskeses since they are not 'removable' scales without tearing the skin from the flesh. Even an educated layman would not see any similarity between the heavy bony plates of the sturgeon or the needle-like projections on the shark skin and the classic kosher scale of the whitefish or carp.

"In Fishery leaflet #531, U.S. Dept. of Interior, Fish & Wildlife Service, Bureau of Commercial Fisheries, Wash. D.C., it states 'swordfish during early juvenile stage of life (up to 8 inches long), have "scales" that are markedly specialized and rather unique. They are in the form of bony tubercules or expanded compressed platelike bodies. These scales are rough, having spinous projections at the surface and they do not overlap one another as the scales in most fish do. With growth the scales disappear and the adult fish including those sold commercially have no scales.'

"The Talmud (Chulin 66A) lists but two exceptions to the absolute requirements of having visible scales:

a) fish that shed their scales when netted, like the mackerel. A black cloth placed in the net beforehand can verify this;
b) fish that have scales developing later in the life cycle; consequently the juvenile fish that lack scales may be eaten since they DO have scales at maturity.

"Nowhere in the Talmud or in responsa literature is there any reference or precedent to such a deviant: a fish that has scales as a juvenile but not as an adult. Therefore, based on the above, swordfish (xiphias gladius) do not possess scales of the kosher variety and is a non-kosher fish" (

Because of the scientific evidence listed here, we've listed the swordfish with other unclean animals.
Based on an article by Cecil E. Maranville, from the www.ucg.org website.