CONTENTS 



Page 



Literature review 1 



Materials examined 2 



Methods 5 



Results 5 



Variation in number of gill rakers with age 5 



Variation in number of gill rakers with sex 6 



Populations 6 



Chesapeake Bay 6 



Above and below Pinopolis Dam, S.C 7 



Hudson River 8 



Comparison of James and Hudson Rivers 9 



Long Island Sound 9 



Comparison of those from California with those 



from Chesapeake Bay and Hudson River 9 



Comparison of those from Canada, Delaware River, 



and Albemarle Sound 10 



An overall comparison 10 



Discussion 11 



Summary and conclusions 13 



Literature cited 14 



