Aj. Fowler et Da. Short, VALIDATION OF AGE-DETERMINATION FROM OTOLITHS OF THE KING-GEORGE WHITING SILLAGINODES-PUNCTATA (PERCIFORMES), Marine Biology, 130(4), 1998, pp. 577-587
The otoliths of the King George whiting Sillaginodes punctata were ass
essed for their usefulness in adult-ageing, Whole, transverse-sectione
d and broken/burnt sagittae displayed alternating opaque and transluce
nt zones. Some small whole otoliths contained accessory areas of pigme
nt, whilst large otoliths were too thick to transmit light, resulting
in ambiguous counts in each case. Both marginal-increment analysis and
treatment of fish with tetracycline demonstrated that the first three
opaque zones formed annually, the first during the spring/summer of t
he second year of life, and the second and third in each subsequent sp
ring. Otolith thickness increased linearly with the completion of each
new opaque/translucent zone. An ageing protocol based on whole otolit
hs, supplemented with the breaking/burning of ambiguous otoliths is re
commended. An algorithm for calculating age in months from otolith cou
nts based on a fi?red birth-date of the mid-point of the spawning seas
on is presented.