Use of otoliths to determine age and growth of largemouth bass in Florida

The annual formation of otolith annuli was validated through age 5 for Florida largemouth bass Micropterus salmoides floridanus. Sectioned otoliths (sagittae) gave more reliable ages than whole otoliths. Beginning at age 2, at least one annulus was obscure in some whole‐otolith mounts, a problem that worsened with fish age. By age 5, over 20% of the whole otoliths gave under‐estimates of true age; otoliths producing these errors came from fish with slower than average growth rates. Sectioned otoliths gave poorer regressions (lower coefficients of determination) of otolith radius on body length than intact structures because the sectioning plane varied slightly among otoliths. Nevertheless, back calculations of fish size and growth from sectioned and correctly aged whole otoliths were equally accurate. Otolith sectioning is the procedure of choice for age‐and‐growth analysis of Florida largemouth bass. Whole otoliths, however, require much less time for analysis than sectioned ones and may be used for rapidly growing fish and fish known to be age 3 or younger.