594 



MARINE PRODUCTS OF COMMERCE 



However, best results seem to be obtained by attaching the lines as nearly amid- 

 ships as possible as it facilitates the steering of the vessel during the trawling 

 process. 



After the net has been trawled for about 30 minutes, the engine is stopped 

 and the net hauled in. Two men stand on the stern and pvill on the towlines until 

 the otter boards are hauled aboard and the slack of the net hauled in. The tail 

 end of the bag containing the catch is then worked around to the side of the boat 

 and hauled aboard. 



Composition 



The edible portion of fresh shrimp compares favorably in protein content with 

 fresh fish. However, it has a very low percentage of fat and consequently a low 

 fuel value per pound. Recently various observers have found that many shrimp 

 have a rather high fat-soluble vitamin content; this is of importance in considering 

 their food value. The proximate composition of cooked, canned, and dried shrimp 

 is given in Table 129. The mineral content of shrimp is shown in Table 130. 



Table 129. Analysis and Food Values of Shrimp. 

 (Calculated on the fresh basis) 



Table 130. Inorganic Content of the Edible Portion of Shrimp. 



Note: Four units to right of decimal point equals parts per million or mg per kg. 



Source: Nilson, W. H., and Coulson, E. J., "The Mineral Content of Edible Portions of 

 Some American Fishery Products," U. S. Bureau of Fisheries, Investigational Rept., 41 

 (1939). 



Fresh raw shrimp, analyzed by Coulson (1935), contain the following per cents: 

 moisture, 79.0; protein (N X 6.25), 17.1; and fat (ether extract), 1.2. Chapman 

 (1926) indicated that shrimp contain 24 parts per milhon of arsenic; however, 

 Coulson, Remington, and Lynch (1935) report that it is organically combined 



