Abstract
Ages of yellowfin grouper (n = 306) from the southeastern United States coast from 1979-2014 were determined using sectioned sagittal otoliths. Opaque zones were annular, forming January-June (peaking in February-March). Yellowfin grouper ranged in age from 3 to 31 years; the largest fish measured 1,000 mm fork length (FL). Body size relationships for yellowfin grouper were: W = 1.22 × 10(-5) FL(3.03) (n = 229, r (2) = 0.92); TL = 1.06 FL - 14.53 (n = 60, r (2) = 0.99); and FL = 0.93 TL + 18.63 (n = 60, r (2) = 0.99), where W = whole weight in grams, FL in mm, and TL = total length in mm. The von Bertalanffy growth equation was: Lt = 958 (1 - e(-0.11(t+2.94))) (n = 306). The point estimate of natural mortality for yellowfin grouper was M = 0.14, while age-specific estimates of M ranged from 1.59 to 0.17 for ages 1-31.