Abstract

The red snapper Lutjanus campechanus is currently under stringent federal management in the Golf of Mexico off the southeastern United States due to apparent overfishing of many populations. Management strategies employed to promote recovery of the species are dependent upon knowledge of various demographic variables such as the ages of individuals, the distribution of these ages (cohort strength) within the population, and maximum longevity. Thus a reliable and accurate ageing methodology for red snapper is of paramount importance. Annuli on otoliths have been used to age many species of fishes, including red snapper. However, the utility of this methodology for ageing red snapper has been questioned by those who dispute both the apparent longevity (over 50 yr) of red snapper and the position of the first annolus within the otolith.\We counted annoli and assessed edge condition in sagittal otoliths of 3,791 red snapper collected from the northern Gulf off Louisiana during the periods 1989 to 1992 and 1995 to 1998. Opaque annoli were validated by marginal increment analysis to form once per year from December through June. Among the otoliths examined, estimated ages ranged from 0.5 to 52.6 yr for individuals from 104 mm to 1,039 mm total length and from 0.017 kg to 22.793 kg total weight. The great heterogeneity in red snapper age at a given total length or total weight limits the use of morphometric variables as predictors of age.

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