Water Animals

Leviticus 11:9–12; Deuteronomy 14:9–10

Manta ray: technically has scales, but is it kosher?Manta ray: technically has scales, but is it kosher?Water animals are simply referred to in Scripture as "all that is in the water," or kol asher bamayim (כל אשר במים).

Marine life, no matter how it is classified biologically, is subject to two conditions in order to be kosher:

  • The animal must have fins.
  • The animal must have scales.

Historically, this has been taken to refer to the typical type of fins and scales you find on most fish. All crustaceans and cephalopods are unclean, as well as smooth-skinned sharks, eels, and catfish. Common kosher fish include salmon, tilapia, trout, tuna, walleye, bass, cod, and mahi-mahi.

There is some uncertainty about what actually qualifies as a scale. Sturgeons, for example, have scale-like bony plates on their skin, but they are different from those of other fish. In cases like this, we need more information about what is meant by a "scale" (Hebrew: kaskeset, קשקשת) in order to determine whether or not the fish is kosher.

It is important to remember that the biblical understanding of a word or concept may not match the scientific definition of its English translation. Thus, it is pointless to look at English dictionaries or biology textbooks to determine what is or is not a "scale" as it pertains to biblical kosher law. According to a strictly scientific standard, even sharks and rays have scales.1

It is sometimes helpful to look at a word's etymology (linguistic historical origin) to determine its meaning, but that can also be misleading, as the meanings of words change over time and sometimes have little or nothing to do with their etymological roots.2 It is occasionally helpful to compare the words with related terms in other languages, but this can also lead one astray, since words can drastically change meaning as they go from one people group to another.3 The safest way to define a word is to consider how the culture has defined the term historically.

Jewish law has come to a specific definition of a scale. If it can be removed from the animal's skin without causing significant damage, then it qualifies as a scale as it pertains to kosher law.4 By this definition, a sturgeon would not be kosher.

Carp: a kosher bottom feederCarp: a kosher bottom feederPeople often note that unclean fish frequently tend to be "bottom feeders." However, it is important to note that the text does not base a marine animal's kosher status on where or what it eats. A fish may very well be a bottom feeder, yet perfectly meet the requirements for kosher status. Carp is one example of such a fish.

Just as in the case of pork, non-kosher marine animals frequently find their way into processed foods. Vegetable stir fry at an Asian restaurant may very well have a non-kosher fish sauce. One cannot assume that fish sandwiches are necessarily a kosher species. For example, McDonalds' famous Filet-O-Fish includes hoki (also known as blue grenadier or blue hake), which is not kosher.5

Once a fish has been skinned and filleted, the species cannot be positively identified. Many non-kosher fish fillets look identical to kosher fillets, so it is entirely possible that a fish may be misidentified or mislabeled at a store. One way to be certain that the species is correctly identified is to purchase fillets that still have at least a small amount of skin.

Fish are often called by several common names, which may also lead to mistaken identity. For example, although true salmon is kosher, "rock salmon" is a common term for the flesh of the spiny dogfish, a non-kosher fish often used in fish-and-chips shops in the United Kingdom.6

  1. 1. "Placoid Scales" Australian Museum http://www.austmus.gov.au/fishes/what/scales/placoid.htm
  2. 2. For example, the etymological root of the English word "seminary" comes from the Latin words for "seed" and "room."
  3. 3. For example, although the French word demande is related to the English word "demand," it means "request, propose" without any urgent or forceful implication.
  4. 4. Ramban, commentary on Leviticus 11:9.
  5. 5. McDonald's USA Filet-O-Fish, http://nutrition.mcdonalds.com/bagamcmeal/itemDetailInfo.do?itemID=5926&...
  6. 6. "Rock Salmon" Shark Trust. http://www.sharktrust.org/content.asp?did=29370