606 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1917. 



moment, although, like all error, regrettable, but when it was about 

 to enter more intimately into commerce and into the knowledge 

 of the people, it became actually misleading, as the meat of the cod 

 is dry, while that of the sablefish is rich, fat, and of different flavor, 

 and requires other methods of cooking. 



The sablefish as caught, averages about 15 pounds in weight al- 

 though it grows much larger. It lives on the banks near the 100- 

 fathom line from southern California to Alaska, being more abun- 

 dant north of San Francisco. Its food consists of small fishes, 

 crustaceans and other bottom-dwelling animals, but little informa- 

 tion concerning its habits has become a matter of record. 



There is another fish on the Pacific coast which has suffered, or 

 perhaps it were better to say benefited, by the same sort of neglect 

 which has been visited on the sablefish, although its habits are such 

 that it has not been regarded by the fishermen as a nuisance. Its 

 possibilities have been merely disregarded. This is the eulachon, re- 

 lated to the smelts which are highly esteemed in various parts of the 

 world, and sometimes erroneously called " Columbia River smelt." 

 During the winter months these little fishes appear in the mouths of 

 coastal streams in great abundance, deposit their spawn and all, or 

 nearly all, die. Each generation, after having provided for its suc- 

 cessor, is completely, or almost completely, exterminated. 



There are a few other species which exhibit this interesting and 

 remarkable phenomenon, and some others show a tendency toward it. 

 In certain of the lakes of Maine the true smelts die in large numbers 

 after spawning, although there is nothing approaching a complete 

 mortality of an entire generation. Studies of the Atlantic salmon 

 have shown that a considerable proportion of the individuals of each 

 generation die after their first spawning, but the most conspicuous 

 examples of this catastrophic life history are found among the 

 several species of the Pacific salmons of the genus Oncorhynchus. 

 These large and handsome fishes have very definite life cycles of 

 from two to four or five years according to the species, and they 

 perish to the last fish after the first act of spawning. Many of these 

 salmon struggle from the sea up the streams against all obstacles 

 for hundreds — in some cases more than a thousand — of miles, until 

 they reach their spawning grounds, and it was at one time supposed 

 that the exhaustion caused by these stupendous exertions and the 

 wounds suffered en route were responsible for the mortality, but it is 

 now known that the same phenomenon occurs in streams but a few 

 miles long. The fact seems to be that the fish meet with a sudden 

 onset of senility. The step from full maturity and adult vigor to 

 old age is bridged by a few weeks, while the stages of youth, adoles- 

 cence and maturity are measured by years. 



