CONTENTS 



Page 



Introduction 1 



Selection and preparation of scales 1 



Examination of scale characteristics 2 



Differences in scale characteristics 



between sexes 3 



Differences in scale characteristics between 



age groups of a brood year 3 



Differences in scale characteristics 



between brood years 3 



Differences in scale characteristics among 



four rivers 4 



Conclusions 5 



Literature cited 5 



