536 U. S. BUREAU OF FISHERIES 



when they can is but natural among fish merchants, and they as 

 naturally prefer to send them to the freezer rather than to the 

 garbage dump when the exigencies of the trade make them unsal- 

 able for the time. Yet fish that are stale when frozen will not be 

 less stale when they are defrosted. Every pound of off-quality 

 fish that is frozen impairs the public esteem of frozen fish. 



It is to be presumed that those in charge on the freezing plat- 

 forms know the marks of fresh, old, or spoiled fish. General marks 

 may be tabulated as follows: 



GOOD FISH BAD FISH 



1. Odor of fish, fishy. 1. Odor stale, sour, or putrid. 



2. Eyes bright, not wrinkled or sunken. 2. Eyes dull, wrinkled, sunken. 



3. Gills bright red, covered with clear 3. Gills dull brown or gray, slime 



slime ; odor under gill covers cloudy ; odor under gill covers 



fresh, fishy. sour and offensive. 



4. Colors bright. 4. Colors faded. 



5. Flesh firm ; in quite fresh fish the 5. Flesh soft and flabby ; impressions 



body is stiff ; impressions made made by fingers remain ; slime ab- 



by fingers do not remain; slime sent (halibut), slime cloudy, 



present and clear (eels, halibut). ropy (eels). 



6. Belly walls intact. 6. Belly walls often ruptured, viscera 



protruding. 



7. Muscle tissue white. 7. Muscle tissue becomes pinkish, es- 



pecially around backbone. 



8. The vent is pink, not protruding. S. The vent is brown, protruding. 



Many fish have marks of quality peculiar to them. Halibut often 

 turn yellowish on the white side, the skin on the tail wrinkles when 

 the tail is bent around, and the belly cavity becomes red and sour- 

 smelling. Eels become covered with a white ropy slime. Such 

 marks can be learned only by experience and careful observation. 

 In some instances freezers, especially those conducted for private 

 business, establish quality grades with more or less definite stand- 

 ards. In public freezers note is taken of the quality and entered in 

 the records. One large private firm uses the following grades for 

 halibut : 



1. Perfect fish : White side not stained or colored ; no cuts or wounds ; 

 black side bright; slime present and clear; blood bright, fresh red; fish firm 

 and plump; smell sweet. 



2. Fish of high grade but for a minor reason not in grade 1 : As slime 

 leaves body a yellow color spreads over white side ; blood blanches and flesh 

 becomes softer. These defects in moderate degree, slight wounds or gray 

 spots on white side will cause halibut, otherwise excellent, to fall into 

 grade 2. 



3. As conditions described under 2 advance, the fish becomes slimeless and 

 yellow, inside of belly cavity pink or stained ; sour odor becomes evident ; 

 flesh soft, imprints of fingers remain ; skin wrinkles when tail is bent ; flesh 

 lean or " loggy " ; white side gray. Still fit for food but far from fancy. 



4. Fish so far spoiled as to be unfit for food. If the inspector himself 

 would not be willing to eat the fish they go in this class. 



CLASSIFICATION OF TRADE SIZES 



At the time of receipt fish are often sorted according to size, and 

 there may be many size categories for one kind of fish. For example, 

 in mackerel there are spikes, tinkers, medium, and large; bluefish, 

 baby, small, medium, large; halibut, chicken, small, medium, large, 

 whales. These are so numerous and varied that they can not be 



