Precision of Three Structures for Saugeye Age Estimation

We evaluated precision of age estimates obtained from sagittal otoliths, scales, and dorsal fin spines from 341 saugeye (Walleye Sander vitreum × Sauger S. canadense) collected from six Kansas reservoirs. Between-reader agreement was greatest for otoliths, followed by dorsal spines, and then scales. Coefficient of variation values for between-reader comparisons for otoliths were 1.3–3.1; whereas, those for dorsal spines were 13.8–18.2. Between-reader comparisons for scales were most variable, with CV estimates between 19.9 and 23.1. Age estimates from otoliths aligned with age estimates from scales more often than those from dorsal spines; although, age estimate comparisons between structures were generally variable. Between-reader agreement for scales and fin rays decreased with increasing estimated age; however, agreement for otoliths generally remained high (i.e., >80%) through age 10. Given greater precision relative to other structures, we recommend the use of sectioned otoliths to estimate a...