Hybrid family of Argopecten irradians irradians was created by fertilization between two northern bay scallop individuals.Two families were analyzed in this study.The first family,Pa-Pb,is a pair mating between two scallops named Pa and Pb,while the second one crossed by individuals of Y1 and P0.Marker inheritance and segregation were studied in the 10 progenies of each family by randomly amplified polymorphic DNA(RAPD) analysis.102 RAPD primers were first screened by parental animals of both families.Only the primers with polymorphisms between the two parental animals in each family were selected for further analysis.In both families,parents and 10 progeny were analyzed with selected primers.In family Pa-Pb,a total of 122 bands generated from 12 selected primers.37 of them were polymorphic between two parents.The maternal Pa of this family had 17 molecular markers while paternal Pb had 20 markers.In Y1-P0,95 bands were produced by 10 selected primers.32 bands were polymorphic between maternal Y1 and paternal P0,who had 17 and 15 molecular markers respectively.In both families,each progeny analyzed in this study had at least 8 maternal markers and 5 paternal markers.Based on segregation patterns at all markers analyzed,we concluded that none of the progeny analyzed were from self-fertilization,and one-way hybridization between two individuals was successful in both of the two bay scallop families.