Age, growth, and mortality of bonefish, A1bula vUlpes, from the waters of the Florida Keys

442 Abstract.-We examined528 bone­ fish ranging from 21 to 702 mm FL col­ lected in South Florida waters from 1989 to 1995. Ages of451 bonefish rang­ ing from 228 to 702 mm FL were esti­ mated from thin-sectioned otoliths (sagittael. Examination ofOTe-marked otoliths from five fish held in a pond in the Florida Keys for periods ranging from 14 to 29 months suggested that a single annulus was formed each year. Marginal-increment analysis also showed that a single annulus was formed each year during March-June. Bonefish reach a maximum age of at least 19 years. Growth of the bonefish in our study was rapid until an age of about six years and then slowed con­ siderably. The von Bertalanffy growth equation for females ~7as FL:680.9(1­ el-O.279IAge+O.9341J1 and for males was FL=670.7( l-eI-O.242IAge+1.31S))). The over­ all growth models for males and fe­ males were significantly different, but estimates of individual growth param­ eters L_. K, and to were not. Predicted lengths of females were greater than those ofmales for all ages greater than 1 year. Catch-curve estimates ofinstan­ taneous rates oftotal mortality (Z) were 0.21 (95% confidence interval 0.167­ 0.303) for females and 0.25 (95% confi­ dence interval 0.098-0.406) for males. Empirically derived estimates of natu­ ral mortality were similar to total mor­ tality estimates. suggesting that fish­ ing mortality is low.