INSPECTION OF FISH
Section I. FISH: THEIR COMPOSITION,ANATOMY, PREPARATION,AND
a. Definition. The term waterfood is applied to the fishery products procured by
the Department of Defense (DOD). When applied, it encompasses all varieties of fresh
and salt-water finfish and shellfish.
b. Finfish. Finfish are those species termed endoskeletal (the skeletal structure
is contained within its body) containing vertebrae, rib bones, and a skull composed of
numerous bones. They are fusiformed (tapering at both ends), roundish, and usually
slightly compressed. Some may be greatly compressed (for example, sun perch), or
depressed (for example, flounder). Their shape offers little resistance to movement in
c. Shellfish. Shellfish are divided into two groups, mollusk and crustacean.
They are referred to as exoskeletal as they have an outer shell covering the body.
d. Quality. There are many complex chemical changes that occur within
waterfood after death. These changes, associated with bacteriological changes,
determine the quality. The best quality available is a waterfood that is cooked and
consumed immediately after death. To perform an adequate inspection, the veterinary
food inspection specialist must be knowledgeable of the chemical composition of
waterfood and the chemical and deteriorative changes that may take place.
The major chemical components of the edible flesh of waterfoods are:
a. Water. Water constitutes the largest component and ranges from 66% to
84%, averaging approximately 80%. The water is mostly intracellular which means that
little water will be lost during normal handling. In fresh fish, the water contains the salt
and minerals and is inversely related to the amount of fat present. The higher the water
content, the lower the fat.
b. Protein. Protein is the second largest component. The amount of protein
ranges from 6 to 28 percent, the average being 18 to 20 percent. Protein contains all of
the essential amino acids required in man's daily diet, making fish an excellent meat
product. It also contains a nitrogen compound which produces the odors associated