DAILY GROWTH INCREMENTS IN OTOLITHS OF JUVENILE WEAKFISH, CYNOSCION REGALIS - EXPERIMENTAL ASSESSMENT OF CHANGES IN INCREMENT WIDTH WITH CHANGES IN FEEDING RATE, GROWTH-RATE, AND CONDITION FACTOR

Laboratory analyses were conducted on age-0 weakfish, Cynoscion regali s, to determine if deposition rate of otolith increments was daily and to examine the relation among otolith increment growth, daily feeding rate, specific growth rate, and condition factor. Tetracycline-marked juveniles (n=58) had a mean deposition rate of 0.98 (0.03 SE) increme nts/d. Feeding rate significantly affected increment width and was pos itively correlated with somatic growth rate and condition factor. Incr ement width response to changes in ration level was immediate, signifi cant differences occurring between day 7 and 14. Mean increment width and specific growth rate were positively correlated (r=0.86). The cont inuation of otolith growth during periods of negative fish growth refl ects the conservative nature of otolith growth and the lack of otolith resorption. An established relation between known growth rates of juv enile weakfish in the laboratory and otolith increment width will allo w otolith increment widths to be applied to field samples. Such analys es could be used to examine closely factors affecting growth, survival , and recruitment.