CONTENTS 



Page 



Introduction 1 



Mussel Shell Industry 1 



Historical significance 1 



Method of harvest 2 



Methods and Materials 5 



Coramercial catch 5 



Brail sampling 5 



Population sampling 6 



Relation of abundance and catch 7 



Hahitat conditions 7 



Age and growth of the pigtoe 7 



Reproduction of the pigtoe 8 



Analyses of Data 8 



Commercial catch 8 



Brail sampling 10 



Population sampling l6 



Relation of abundance and catch 21 



Habitat conditions 2k 



Age and growth of the pigtoe 28 



Reproduction of the pigtoe 30 



Comparison of Results 3^ 



Conclusions 39 



Acknowledgments kl 



References -42 



iii 



