Comparative age-specific demography of four commercially important deep-water snappers: implication for fishery management of a long-lived lutjanid.

Lutjanid snappers belonging to the subfamilies Apsilinae and Etelinae are commercially valuable components of tropical deep-water fisheries throughout much of the Indo-Pacific region. Based on age assessment using sagittal otoliths, the age-specific demographic characteristics of four deep-water snappers, Etelis coruscans, Paracaesio caerulea, Pristipomoides filamentosus and Pristipomoides sieboldii, in the Okinawa Islands, southwestern Japan, were examined, and the results were discussed for fishery management. Age validation using edge-type analysis demonstrated that opaque zones in all species were formed once per year and were considered valid annual growth increments.