with deterioration. Protein is heat, water, and salt soluble and can be destroyed by
improper handling and storage.
c. Fat. Fat, or lipid, content ranges from less than 1 percent to as much as 28
percent. Waterfoods containing 6 percent or less are referred to as lean fish while
those that exceed 6 percent are classified as "fatty." Fish body fats are polyunsaturated
fatty acids and combine easily with oxygen resulting in oxidation, a major storage
problem. Because of the total properties of the fats, fish is an excellent meat for people
on low cholesterol diets. Haddock is an example of lean fish and Chinook salmon is an
example of "fatty" fish, with 12% fat.
d. Inorganic Compounds. Inorganic components make up the smallest
percentage of the four major components. Practically every mineral element contained
in sea water (for example, zinc, phosphorus, copper, iron, iodine, potassium, and
chlorine) may be found in the flesh of fish. When present in the fish habitat,
contaminants such as mercury, pesticides, herbicides, and radionuclides may also be
found in fish flesh.
e. Minor Chemical Components. Vitamins are a minor chemical component in
fish. Fish oils are high in levels of fat-soluble vitamins A, D, and E. Combined with
minerals, vitamins constitute 0.8% to 2% of fish flesh.
a. General. The inspector should be knowledgeable concerning the external
anatomical features of fish, including anatomical terms of location. This is needed to
identify different species. A familiarization with internal anatomical features is also
b. Anatomical Terms of Location. Anatomical terms of location are:
(1) Posterior. Toward the rear; away from the head; tail area.
(2) Anterior. Toward the head; away from the tail; head area.
(3) Dorsal. Toward the backline.
(4) Ventral. Toward the bellyline.
(5) Medial. Toward the middle.
(6) Lateral. Away from the middle.