Abstract

The preparation of sagittal otoliths for examination by light microscopy and by scanning electron microscopy (SEM) has revealed the presence of apparent daily growth increments which can be used to estimate the age of wahoo. This will provide estimates of important growth and reproductive parameters in this economically important pan-tropical species. Preliminary counts of the daily increments in a size range of specimens confirm that this is a relatively fast-growing species, in common with other commercially important scombroids. Validation of the daily increments will be attempted with tagging and injection with oxytctracycline (OTC). There are similarities in the microstructure of the sagittae of yellowfin tuna and wahoo which can be useful in verifying the estimates of growth rates in wahoo.

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