Verification of the Formation of Annuli in Otoliths of Largemouth Bass

Annuli in transverse thin sections of otoliths from largemouth bass Micropterus salmoides were verified by four methods. First, the number of daily rings between successive annuli was similar to the potential number of growing days in each of the first 3 years of life. Second, all of the annuli were formed between the last of April and the first part of July. Third, the lengths of age-I-VI largemouth bass back-calculated from otoliths were very similar to those determined from a mark-recapture study. Fourth, the number of otolith annuli agreed with the known ages (II+ and V+) of largemouth bass in samples from a hatchery and a lake.