Fish which have fins and scales are kosher. Fish which only have fins are not kosher. Of the four types of scales, clenoid, cycloid, ganoid and placoid, only clenoid and cycloid scales are valid according to the Torah. Gandoid is the type found on sturgeon and placoid is found on shark.There is no prohibition against eating fish blood, other than the fact that people may think that a person is eating prohibited blood, and ritual slaughter is not required. The scales must be true scales that can be removed without damaging the skin of the fish. As it says in the Torah – "These you may eat of the fishes, all that have fins and scales…" (Vayikrah XI:9-12) Bony tubercles and plate or thorn-like scales that can be removed only by removing part of the skin are not considered scales in this context. Some fish that have such scales, such as eels, lumpfish, shark, sturgeon, and swordfish, are not kosher.

All shellfish and mammals (such as whales, and dolphins) are not kosher. Only the eggs of kosher fish, such as fish roe or caviar, are allowed, therefore supervision is necessary. Care must be taken when buying fresh, whole fish, filleted, or frozen, because of the possibility of substitution by non-kosher fish or of contamination by remnants of non-kosher fish from knives and cutting boards. Fish sticks have three problems: the fish, the oil, and the frying utensils and equipment (which is usually used for non-kosher fish as well as kosher fish). Smoked fish is frequently soaked in brine and then smoked along with non-kosher fish. According to Jewish law, this soaking and smoking is tantamount to cooking over a flame and therefore the product is not kosher. Smoked fish is also often packed in oil, which may not be kosher. Although herring is famous as a Jewish food, it is not always kosher. The preparation of herring can pose a myriad of problems among which are mono- and di-glycerides, non-kosher wine vinegar or wine, sour cream, bread crumbs, spices, and equipment contamination. These lists of kosher and non-kosher fish were prepared by James W. Atz, Ph.D., Curator and Dean Bibliographer in the Department of Ichthyology of the American Museum of Natural History, New York, New York 10024. I would like to thank Rabbi Genack and the Union of Orthodox Jewish Congregations of America for allowing us to reprint this list.

Angler See: Goosefishes
Beluga See: Sturgeons
Billfishes (Family Istiophoridae). Including: Sailfishes (Istiophorus species); Marlins and spearfishes (Tetrapterus species, Makaira species)
Blowfish See: Puffers
Bullhead See: Catfishes
Cabezon See: Sculpins
Catfishes (Order Siluriformes). Including: Channel catfish (Ictalurus punctatus); Bullheads (Ictalurus species); Sea catfish (Arius felis)
Cutlassfishes (Family Trichiuridae) including: Cutlassfishes (Trichiurus species) Scabbardfishes (Lepidopus species)
Dogfish See: Bowfin, Sharks
Eels (Order Anguilliforms). Including American and European eel (Anguilia rostrata and Anguila anguila); Conger eel (Conger oceanicus).
Gars (Order Semionotiformes). Freshwater gars (Lepisosteus species).
Goosefishes or anglers (Lophius species)
Grayfish See: Sharks
Lampreys (Family Petromyzontidae)
Leatherjacket See: Jacks (Oligoplites saurus)
Lomosuckers (Family Cyclopteridae). Including: Lumpfish (Cyclopterus lumpus); Snailfishes (Liparis species).
Marlin See: Billfishes
Midshipman See: Toadfishes
Ocean pout or eelpout (Macrozoarces americanus)
Oilfish (Ruvettus pretiosus) Puffers (Family Tetraodontidae).
Paddlefish See: Sturgeons
Pout See: Ocean pout
Puffers, blowfishes, swellfishes, sea squab (Sphoeroides species)
Ratfish See: Sharks
Ray See: Sharks
Rock prickleback or rockeel (Xiphister mucosus)
Sailfish See: Billfishes
Sculpins (Family Cottidae). Including: Sculpins (Myoxocephalus species, Cottus species, Leptocottus species, etc.). Cabezon (Scorpaenichthys marmoratus); Searaven (Hemitripterus americanus)
Searaven See: Sculpins
Sea-squab See: Puffers
Sharks, rays and their relatives (Class Chondrichthyes). Including Grayfishes or dogfishes (Mustelus species, Squalus species); Soupfin shark (Galeorhinus zyopterus); Sawfishes (Pristis species); Skates (Raja species); Chimaeras or ratfishes (Order Chimaeriformes).
Skates See: Sharks
Snake mackerels (Gempylus species)
Spoonbill cat See: Sturgeons
Sturgeons (Order Acipenseriformes). Including: Sturgeons (Acipensen species, Scaphirhynchus species); Beluga (huso uso); Paddrefish or spoonbill cat (Polyodon spathula)
Swordfish (Xiphias gladies)
Toadfishes (Family Batrachoididae). Including: Toadfishes (Opsanus species); Midshipment (Porichthys species).
Tiggerfishes and firefishes (Family Balistidae). Triggerfishes (Balistes species, Canthidermis species)
Trunkfishes (Family Ostraciidad). Trunkfishes and cowfishes (Lactophrys species).
Wolffishes (Family Anarhichadidae). Including: Wolffishes or ocean. catfishes (Anarhichas species)

The following are the common names, in several different languages, of some Kosher fish. The names are those applied in the areas where the species occur or are commonly known. The species are listed alphabetically according to the English standard common name.

ALBACORE
French: germon
German: Weisser Thun
Hawaiian: ahipalaha
Italian: alalonga
Japanese: bin'naga, binnagamaguro, binchô, tombo
Portuguese: voador, albacora, albacora branca
Spanish: albacora, atún blanco, bonito del norte
BARRACUDA, great
French: barracuda, bécune, brochet de mer
German: Grosser Barrakuda
Hawaiian: kaku
Italian: barracuda, sfirena
Japanese: onikamasu
Portuguese: barracuda, bicuda americana
Spanish: barracuda, picua, picúda, bicuda, espetón, picúa brava, picúa corsaria, picúa zorra
BASS, European
French: bar
German: Seebarsch, Wolfsbarsch
Italian: spigola
Spanish: lubina
BASS, giant sea
French: merou géant du Pacifique
Japanese: ishinagi-zoku
Spanish: mero gigante del Pacifico, cherna, lubina marina gigante
BASS, striped
Spanish: lobina rayada, lobina barrada, lubina listada
BLUEFISH
French: tassergal, balarin
German: Blaufisch, Wolfsbarsch
Italian: pesce serra, ballerino
Japanese: amikiri, okisuzuki, okisade
Portuguese: anchova, enchova
Spanish: anchoa, anjova
BONITO, Atlantic
French: bonite à dos rayé
German: Bonito, Pelamide
Italian: palamita
Japanese: hagatsuo-rui
Portuguese: serrajao
Spanish: bonito (del Atlántico), carachana
BONITO, Paciflc
Japanese: hagatsuo, kitsunegatsuo
Spanish: bonito (del Pacifico)
COD, Atlantlc & Pacific
French: morue, cabillaud, fraiche,
morue franche
German: Kabeljau, Dorsch
Italian: merluzzo bianco
Japanese: madara, tara-ka
Portuguese: bacalhau
Spanish: bacalao, bacallao
DOLLY VARDEN
Russian: malma
DOLPHIN
French: coryphene, dauphin
Hawaiian: mahi mahi
Italian: corifena, lampuga, pappagallo
Japanese: shiira
Portuguese: dourado
Spanish: dorado, lampugus, llampugas, peje vapor
HALIBUT, Atlantic
French: flétan de l'Atlantique
German: Heilbutt
HALBUT, Pacific
Japanese: ohyo-rui
JEWFISH
Portuguese: mero, garoupa
Spanish: mero, cherna, guasa, mero sapo, mero-cherna, mero brasil, pez judío
MACKEREL, king
Portuguese: cavala real, serra
Spanish: carite rey, caballa real, sierra, carita, sierra grande, sierra de altura, sierra canalera, carite lucio
MACKEREL, Spanish
Spanish: sierra, carite pintado
PERCH, white
French: bar-perche
POLLACK
French: lieu jaune, colin jaune
German: Pollack
Italian: merluzzo giallo
Portuguese: badejo, juliana
Spanish: abadejo
POLLOCK
French: lieu noir, colin, merlan noire, goberge
German: Kohler, Seelachs
Portuguese: escamudo
Spanish: abadejo, abadejo negro, badejo
SALMON, chinook
Russian: Tshawytscha
SALMON, chum
Russian: keta
SALMON, coho
Russian: kisutch
SALMON, pink
Fiussian: gorbuscha
SALMON, sockeye
Russian: nerka
SEABASS, Japanese
Japanese: suzuki
SEABASS, blackfin
Japanese: hira-suzuki
SEABASS, white
Spanish: cabaicucho, corvina blanca, pescadilla
TROUT, brook
French: truite
TROUT, lake
French: touladi
TUNA, bigeye
French: thon obese, patudo, thon ventru
Hawaiian: po'o-nui, ahipo'o-nui
Japanese: mebachi, shibi
Portuguese: patudo
Spanish: atun ojo grande, patudo
TUNA, blackfin
Japanese: taiseiyômaguro
Portuguese: albacorinha, atum-preto
Spanish: atún aleta negra, atún aletinegro, albacora
TUNA, bluefin
French: thon touge
German: Blauflossenthun, Roter Thun
Italian: tonno
Japanese: kuromaguro, hon-maguro, maguro
Portuguese: atum, atum-azul
Spanish: atún aleta azul, atun gigante, atún rojo
TUNA, dogtooth
French: thon blanc
Japanese: isomaguro
TUNA, longtail
Japanese: koshinaga
TUNA, skipjack
French: bonite à ventre rayé
Hawaiian: aku
Italian: tonnetto striato
Japanese: katsuo
Portuguese: gaiado, listao, listado
Spanish: listado, bonito artico, barrilete
TUNA, southern bluefin
French: thon (rouge) du sud, thon rouge austral
Japanese: minamimaguro
TUNA, yellowfin
French: albacore, thon à nageoires jaunes
German: Gelbflossenthun
Hawaiian: ahi, ahimalailena malailena
Italian: albacore, tonno albacora
Japanese: kihada, kiwade, kiwada maguro
Portuguese: albacora, atum amarello
Spanish: atun de aleta amarilla, atún
de Allison, rabil
WHITEFISH, lake
French: grand coregone
YELLOWTAIL, California
Spanish: jurel de Castilla, colarubia, colirubia, pez limon, seriola de California
YELLOWTAIL, southern
French: sériole australe, liche
Portuguese: seriola do sul, olhete, charuteiro
Spanish: jurel de Castilla, colarubia, colirubia, pez limón, seriola austral