16^ème séminaire 2011-2012

Chih-Wei CHANG

The highly euryhaline grey mullets (Mugilidae) are the so-called estuarine-related or estuarine-dependent fishes because they require an estuarine habitat in their life cycle. By examining microstructure and microchemistry in otoliths, recent works on life history patterns of the fish were summarized.
   
1) An accessory primordium and secondary growth zone with unique microstructure and microchemistry were observed in otoliths of juvenile Mugil cephalus collected in estuaries, which can be used as a biological tracer to determine the age of the fish at recruitment and refine the reconstruction of their early life-stage environmental history.

2) Diversity of the migratory environmental history of freshwater resident and origin of an occasion of mass mortality of Mugil cephalus in a Taiwanese river were well determined by the Sr/Ca and Ba/Ca ratios in otoliths.

3) Examinations of estuarine use and movement patterns of seven sympatric mugilid fishes in a Taiwanese river estuary, and migratory environmental history of two mugilid fishes in Mexican coastal waters revealed both intra-specific and inter-specific variations. Ongoing otolith-based works on mullet life history patterns will be also addressed.