VELIGERS FROM 2 POPULATIONS OF SCALLOP PLACOPECTEN-MAGELLANICUS EXHIBIT DIFFERENT VERTICAL DISTRIBUTIONS IN THE SAME MESOCOSM

Veligers of the giant scallop, Placopecten magellanicus, spawned from parents that came from two different populations (Georges Bank and Pas samaquoddy Bay), were maintained together in large mesocosms 0.6 m in diameter and 9.0 m deep. A new microsatellite probe (PMMS-130) develop ed by Gjetvaj et al. (unpublished observation) was used to distinguish the population of origin of the veligers. Samples obtained at various depths confirmed that the vertical distribution of the two population s differed. These results confirm population differences in vertical m igration behavior seen in a previous study and indicate the value of t he microsatellite probe for larvae as well as the efficacy of mesocosm replication techniques.