Laboratory experiments with known-age bloater larvae raised under constant photoperiod (12 h light: 12 h darkness) showed that deposition of otolith rings began at first feeding and occurred daily at all but the lowest growth rates. Based on ring counts, the age of individual bloaters could be estimated within ±6 d over the first 5 months of life. Otoliths of larvae fed high rations interrupted by 5-d periods of starvation or low rations contained obvious bands of abnormally low-contrast rings corresponding to these stress periods. The relationship between fish length and otolith diameter varied among experiments, independent of growth rate. Therefore, back-calculation of length at age will require an estimate of this relationship for each field application.