Preliminary Investigations into the Age and Growth of the Shortfin Mako, Isurus Oxyrinchus, White Shark, Carcharodon Carcharias, and Thresher Shark, Alopias Vulpinus, in the Western North Atlantic Ocean

Preliminary analysis of the vertebrae of these three species indicate that the current processing method is adequate for counting bands. Sample collection is ongoing and it is likely that more will be obtained for the shortfin mako and thresher shark, though not for the white shark. Complete studies on the age of these species using the entire vertebral samples, tag/recapture data and length frequency analysis for verification are ongoing. Validation of band pair periodicity, which is critical for obtaining accurate ages, will be included in these studies. Information resulting from these studies will include species and sex specific growth rates, size at age, age at maturity, and longevity. The results of this preliminary analysis indicate that the vertebral centra are appropriate structures to use for aging these species. Because of the exploratory nature of these analyses and inadequate samples sizes these data should not be used to estimate growth function parameters for analytic results.