View article

We used an electron probe microanalyzer (EPMA) to determine the migratory environmental history of the catadromous grey mullet Mugil cephalus from the Sr: Ca ratios in otoliths of 10 newly recruited juveniles collected from estuaries and 30 adults collected from estuaries, nearshore (coastal waters and bay) and offshore, in the adjacent waters off Taiwan. Mean (±SD) Sr: Ca ratios at the edges of adult otoliths increased significantly from 6.5±0.9 x 10-3 in estuaries and nearshore waters to 8.9±1.4 x 10-3 in offshore waters (p< 0.01), corresponding to increasing ambient salinity from estuaries and nearshore to offshore waters. The mean Sr: Ca ratios decreased significantly from the core (11.2±1.2 x 10-3) to the otolith edge (6.2±1.4 x 10-3) in juvenile otoliths (p< 0.001). The mullet generally spawned offshore and recruited to the estuary at the juvenile stage; therefore, these data support the use of Sr: Ca ratios in …