GENE FLOW AND INTROGRESSION WITHIN AND AMONG 3 SPECIES OF ROCKFISHES,SEBASTES-AURICULATUS, SEBASTES-CAURINUS, AND SEBASTES-MALIGER

The genus Sebastes comprises at least 100 species worldwide and is the largest genus of marine fishes in the eastern North Pacific. Species within the genus are closely related, and many sibling species exist. Allozyme analysis and restriction analyses of mitochondrial DNA (mtDNA ) were used to investigate genetic differentiation and introgression w ithin and among three nearshore species of the subgenus Pteropodus, Se bastes auriculatus (brown rockfish), S. caurinus (copper rockfish), an d S, maliger (quillback rockfish), Geographic differentiation was dete cted within each species in collections ranging from California to sou theast Alaska, In addition, significant shifts in allozyme frequencies were noted for S, maliger from Puget Sound, Washington, and adjacent areas separated by less than 70 km, Alleles characteristic of the othe r two species were absent from samples of S, maliger outside Puget Sou nd but were consistently observed within Puget Sound, Joint analysis o f the allozyme and mtDNA data indicates that introgression may be occu rring between all three species in Puget Sound and that it may be an i mportant source of diversity in Sebastes.