Age, growth, and natural mortality of schoolmaster (Lutjanus apodus) from the southeastern United States

Ages of schoolmaster (n = 136) from the southeastern Florida coast from 1981–2015 were determined using sectioned sagittal otoliths. Opaque zones were annular, forming March–July (peaking in May–June). Schoolmaster ranged in age from 1–42 years; the largest fish measured 505 mm total length (TL) and was 19 years old. The oldest fish measured 440 mm TL. Estimated body size relationships for schoolmaster were: W = 9.26 × 10(−6) TL(3.11) (n = 256, r(2) = 0.95); W = 2.13 × 10(−5) FL(2.99) (n = 161, r(2) = 0.95); TL = 1.03 FL + 10.36 (n = 143, r(2) = 0.99); and FL = 0.96 TL − 8.41 (n = 143, r(2) = 0.99), where W = whole weight in g, FL = fork length in mm, and TL in mm. The fitted von Bertalanffy growth equation was: L(t) = 482 (1 − e(−0.12(t+2.79))) (n = 136). Based on published life history relationships, a point estimate of natural mortality for schoolmaster was M = 0.10, while age-specific estimates of M ranged from 1.57–0.18 for ages 1–42.