11 



being able to complete the entire life cycle in the laboratory and to control 

 matings. One problem in studying shrimp genetics has been the necessity of 

 obtaining ovigerous (egg-bearing) females from the field. This inability to 

 cause females to produce eggs on demand and to fertilize these eggs with 

 males of known genetic background has not only hampered stock selection programs, 

 but also has dramatically curtailed the economic development in the United States 

 of commercial shrimp farming. 



The utilization of shrimp hatcheries for stock enhancement would require 

 pilot studies both to develop the technology and to assess the economic 

 feasibility of this procedure. 



Pacific Salmon 



Five species of salmon found in the Pacific have commercial value to the 

 United States fishing industry. They are: Oncorhynchus gorbuscha {the pink 

 or humpback) ; 0. keta (chum or dog) ; O^. kisutch (Coho or silver) ; O. nerka 

 (red or sockeye) ; and O. tschawytscha (king or chinook) . 



Management and stock enhancement of salmon has reached a high state of 

 technology relative to other fisheries. This technology is based on about a 

 century's experience in research and development. Pacific salmon have certain 

 behavior characteristics which have been capitalized on in developing the 

 industry. All species exhibit a similar life history pattern in which the 

 eggs are laid in freshwater streams or lakes. Upon emergence from the egg, 

 the young (fry) either remain in fresh water from 1 to 4 years on their 

 migration to the sea (Coho, sockeye, and king salmon) or migrate directly to 

 the sea with little or no feeding (pink and chum salmon) . Juvenile fish are 

 found in coastal waters and make their way to the open sea. After about 1 to 4 

 years at sea (the time varies with species) the migration to home streams occurs 

 for purposes of reproduction. The timing of this migration is fairly precise 

 with little variance from year to year. 



