A number of chemicals used in processing seafood to help retain moisture and improve appearance. Also called dips. Any additives used must be listed on product labels. Excessive use of some additives may cause toughening of seafood products or produce off odors during cooking.

Fish that hatch in fresh water, migrate to salt water to mature and then return to fresh water to spawn. Salmon are an anadromous species. Species that migrate in the opposite direction are called catadromous.

Growing or farming finfish or shellfish in pens or ponds or on growing surfaces such as posts or ropes. Mariculture denotes a saltwater environment.

A type of hook-and-line fishing gear used to catch snappers and groupers.

Deterioration in the belly cavity caused by enzyme action.

A fish or shrimp that has been split. Fish can be split open and boned out or not, producing two sides of the fish joined by the belly skin or the back.

Raw fish or shellfish slices mixed with oil and vinegar or other acidic marinades, such as lime juice, and "cooked" by several hours of soaking. Ceviche is flavored with salt, spices, onion, etc.

Indicates the process of cooling fish thoroughly to a temperature approaching that of melting ice.

The bones just behind the gills; they support the pectoral fins. The collar is waste when a fish is steaked or filleted. Most headless fish are sold with the collar on because it protects the fish.

Removing the fat layer underneath the skin on oily species for milder flavor and improved shelf life. Also called defatted.

Whole fish that have been gutted and scaled and from which the gills have been removed. Usually the fins are removed as well.

Weight loss that occurs as a seafood product gives up moisture. Also, loss of moisture during the thawing of frozen seafood.

The fattest part of a fish, mostly along the belly walls and lateral line. The fat line is often removed for milder flavor and improved shelf life.

A portion of flesh taken from either side of a fish. It is cut parallel to the central bones of the fish. The main bones, fins and belly flaps are usually removed from finished fillets.

A fillet cut for large flatfish, such as halibut. The fletch is then further divided into boneless portions.

White, chalky surface dehydration, most common on corners or narrow edges of product. In the initial states, slight freezer dehydration can be confused with natural product coloration or crust freezing, which is common in some IQF products. Excessive freezer burn indicates exposure to cold air and results in loss of natural juices, contamination and rapid oxidation or rancidity of product. Excessive ice crystals inside containers and wrappings denote moisture migration during temperature fluctuations that may have involved a partial thaw.

Indicates fish were quickly frozen while still fresh.

Fish that have been subjected to freezing in such a manner as to preserve the inherent quality of the fish, generally by reducing their average temperature to 0 degrees F or lower. The ideal temperature for most frozen fish is –20 degrees F.

The separation of the individual flakes of meat that make up a fillet. Pronounced gaping can cause the fillet to fall apart when the skin is removed. Gaping can be a natural feature of the fish or a result of poor handling. Anything that tends to reduce the freshness and quality of fish can increase the possibility of gaping. Gaping also describes live shellfish. Slight gaping of the shell is acceptable, if the shellfish closes tightly when lightly trapped. Severe gaping indicates the animal is dead and that the shellfish should not be eaten.

A commercial fishing net that hangs vertically in the water. Once a fish's gillplate has passed through the mesh, the fish cannot back out.

Indicates the fish has been dipped in water after freezing. Ice forms a glazed surface around the body of the fish or mean, protecting it from damage by freezer burn; i.e. the loss of natural juices, contamination and rapid oxidation or rancidity.

Hazard Analysis of Critical Control Points. The basis of a voluntary seafood inspection program overseen jointly by the National Marine Fisheries Service and the Food and Drug Administration. Emphasis is on ensuring product hygiene and integrity at the various points at which control is exercised over seafood production and handling.

An organic substance released from the tissues of harvested fish as a result of improper temperature control. The condition can be prevented by proper handling and rapid cooling after capture. Histamine concentrations produce food=-poisoning symptoms in humans. Poorly handled mahi mahi, tuna and bluefish are the most commonly implicated species. The condition is also called scombroid poisoning due to its association with the tuna family.

Fish exposed to smoke at gradually increasing temperatures (up to 180 degrees F) over a period of 12 to 18 hours, resulting in coagulation of the protein. The product is cooked through, has a dry texture and crumbles and flakes the same as any cooked fish. The flavor is intensely smoky.

A sensory organ along each side of the head and body of fishes, probably for detecting vibrations, currents and pressure.

A bacterium that can cause the illness listeriosis in humans. Listeria is linked to ready to eat foods that are not further cooked before being eaten, but there is no direct association between listeriosis and consumption of seafoods.

Swordfish or mahi mahi carcasses that have been headed, gutted and tailed, with the belly flaps trimmed.

The central, thick part of a fish fillet, above the belly. Large fillets from fish such as tuna are often called loins.

Indicates that the seafood has been cured in a acidic solution, such as vinegar.

The front and thinnest part of a fillet, around the belly area.

Weight of the product without packing material of glaze.

Refers to salmon that are still in the ocean and are therefore bright and firm. "Ocean-run" is also used by seafood companies to indicate a pack of random-weight products.

Fatty acids found in seafood and other sources. Recent research as found that these fatty acids can have a beneficial effect on the cardiovascular system as well as other aspects of human health.

Tapeworms (cestodes), flukes (trematodes) or roundworms (nematodes) found in fish flesh. Freezing fish to 0 degrees F for one week or cooking it to temperatures higher than 140 degrees F renders worms harmless. For aesthetic reasons, parasites should be cut out of fish flesh before reaching the consumer.