United States Department of the Interior 

 Oscar Lo Chapman^ Secretary 

 Fish and Wildlife Service 

 Albert Mo Day, Director 



Special Scientific Report ~ Fisheries 

 NOo 15 



STUDIES ON THE PACIFIC PILCHARD OR SARDINE 

 (SARDINOPS CAERTTLEA ) 



CONTENTS 



Page 

 lo structure of a Research Program to Determine 



How Fishing Affects the Resources by Oscar Eo Setteo •oooooo 1 



2o Determination of the Age of Juveniles by Scales and 



Otoliths 5 by Lionel Ao Walford and Kenneth He Mosher • o » ooo«31 



So Determination of Age of Adults by Scales, and Effect 

 of Environment on First Year's Growth as it Bears 

 on Age Determination, by Lionel A<, Walford and Kenneth Eo Mo:£b3fo ^6 



4o Influence of Temperature on the Rate of Development of Pilchard 



Eggs in Naturej, by Elbert Ho Ahlstrom ooeooa».eoooo o-^ 



5o A Method of Computing Mortalities and Replacements, 



uy Ra±ph ro oio-ximan oe««ooeo ooooooooooooo ©-OO 



?o Thermal and Diurnal Changes in the Vertical Distribution of Eggs 



and Larvae J by Ralph Po Silliman ooooooo o aeoeooo J81 



Notes This is a reissue of Special Scientific Reports 19-24, 

 ■ issued in 19438 



