Age, Growth, and Mortality of Lane Snapper from Southern Florida

Abstract

Rings on sectioned otoliths were used to determine ages of lane snapper, Lutjanus synagris, sampled from the south Florida headboat and commericial handline and trap fisheries. Rings were identified and counted on 76% of the otoliths examined, and measurements were made on 61%. The oldest fish encountered was 10 years and 512 mm TL. Back-calculated mean lengths at annulus formation were 135, 196, 233, 261, 285, 310, 338, 367, 411 and 426 mm TL for age groups 1 to 10, respectively. The von Bertalanffy equation describing theoretical growth was ℓt = 501 (l-6-0.1337(t+1.49)). The length-weight relationship was W = 0.000102TL2.6524. The relationship of fork length to total length was TL = -2.6252 + 1.0891 FL. Lane snapper were fully recruited to the hook-and-line fishery as 5 year old fish. A Beverton and Holt yield-per-recruit model suggests a maximum yield-per-recruit of 500 g when instantaneous fishing mortality was 0.5 and recruitment ages were 1.5 to 3.0 years.