Validation of age estimates obtained from juvenile pallid sturgeon Scaphirhynchus albus pectoral fin spines

Summary Pallid sturgeon Scaphirhynchus albus are a federally‐listed endangered species, yet little is known about their population dynamics, including age and growth. Age validation is needed before the accuracy of age estimates and ensuing analyses is known. Therefore, we evaluated the accuracy and precision of age estimates obtained from 36 pallid sturgeon recaptured from the lower Missouri River. Accuracy of age estimates varied among three readers from 28 to 41%. Most deviations from the actual age were within 1 year, and most fin spine sections were overaged due to an apparent false annulus near the focus of the section. Between‐reader agreement varied by reader combination but was generally around 30%. Our findings suggest that careful attention be paid to age and growth information obtained from hatchery‐reared pallid sturgeon fin spines and further methods of accurately estimating age of pallid sturgeon need to be developed.