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

PeerJ. 2016 Oct 4:4:e2543. doi: 10.7717/peerj.2543. eCollection 2016.

Abstract

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 × 10-6TL3.11 (n = 256, r2 = 0.95); W = 2.13 × 10-5FL2.99 (n = 161, r2 = 0.95); TL = 1.03 FL + 10.36 (n = 143, r2 = 0.99); and FL = 0.96 TL - 8.41 (n = 143, r2 = 0.99), where W = whole weight in g, FL = fork length in mm, and TL in mm. The fitted von Bertalanffy growth equation was: Lt = 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.

Keywords: Age and growth; Life history; Lutjanidae; Natural mortality.

Grants and funding

Funding for this research was provided by funds granted by the US Congress to the NOAA National Marine Fisheries Service. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.