Abstract

Life history parameters such as age-and-growth estimates are necessary for stock assessments and management of commercially and recreationally important species such as Red Snapper Lutjanus campechanus. Perhaps the most widely accepted method to establish age in Red Snapper is by counting the number of opaque bands on otoliths (one increment consists of a translucent and an opaque band). However, when counting opaque bands it is critical that the increments are validated as annular. Mark-recapture of oxytetracycline (OTC) marked fish and marginal increment analysis (MIA) methods were used on Red Snapper to validate periodicity and timing of opaque band formation. Annual otolith increment formation rates were validated for recaptured Red Snapper (n = 65) at liberty for 0.8 to 11 years. However, the timing of opaque band formation varied from most previous studies, with most opaque bands formed from June through November with peak formation in September (dorsal axis = 68 %, ventral axis = 76% percent frequency). An annual formation rate and opaque band formation peaks during the summer from June to August were also supported by MIA for age-1 to age-16 fish (n = 595). This unusual summer-fall formation of opaque bands has important implications for Red Snapper aging studies, especially when attempting to link environmental disturbances to year-class abundance.

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