ABSTRACT
Introduction ............................................................................................................ 131 Methods ................................................................................................................. 133
Collections ................................................................................................. 133 Isolation and Characterization of Microsatellites ...................................... 134 Statistical Analyses ..................................................................................... 134
Results .................................................................................................................... 135 Within-Population Diversity ....................................................................... 135 Among-Population Divergence ................................................................... 136
Discussion .............................................................................................................. 141 Acknowledgments .................................................................................................. 143 References .............................................................................................................. 143
Atlantic tarpon (Megalops atlanticus) represent a valuable component of the recreational shery across a distribution that encompasses coastal and nearshore waters of the Caribbean Sea, Gulf of Mexico, and the western Atlantic from Canada to
Brazil. Peripheral populations occur in the eastern Atlantic off Africa and the Paci c of Panama. Tolerant of wide ranges in salinity and oxygen concentrations, tarpon distribution is limited by sensitivity to low temperature at the northern extreme of the range (Zale and Merri eld, 1989). The reproductive cycle of tarpon is complex. Adults spawn offshore (Crabtree et al., 1992), eggs and larvae have an extended planktonic stage followed by recruitment into fresh and brackish water nursery areas, and juveniles spend 4-5 years in rivers, bays, and estuaries before joining offshore aggregations of adults (Crabtree et al., 1995). Adults in some portions of the range are highly migratory. They move from spawning sites to forage areas on a seasonal basis (see Luo et al., Chapter 18, this volume).
