Southeastern Naturalist 225 Z.B. Klein, T.F. Bonvechio, B.R. Bowen, and M.C. Quist 2017 Vol. 16, No. 2 SOUTHEASTERN NATURALIST 2017 16(2):225–234 Precision and Accuracy of Age Estimates Obtained from Anal Fin Spines, Dorsal Fin Spines, and Sagittal Otoliths for Known-Age Largemouth Bass Zachary B. Klein 1,* , Timothy F. Bonvechio 2 , Bryant R. Bowen 2 , and Michael C. Quist 3 Abstract - Sagittal otoliths are the preferred aging structure for Micropterus spp. (black basses) in North America because of the accurate and precise results produced. Typically, fisheries managers are hesitant to use lethal aging techniques (e.g., otoliths) to age rare species, trophy-size fish, or when sampling in small impoundments where populations are small. Therefore, we sought to evaluate the precision and accuracy of 2 non-lethal aging structures (i.e., anal fin spines, dorsal fin spines) in comparison to that of sagittal otoliths from known-age Micropterus salmoides (Largemouth Bass; n = 87) collected from the Oc- mulgee Public Fishing Area, GA. Sagittal otoliths exhibited the highest concordance with true ages of all structures evaluated (coefficient of variation = 1.2; percent agreement = 91.9). Similarly, the low coefficient of variation (0.0) and high between-reader agreement (100%) indicate that age estimates obtained from sagittal otoliths were the most precise. Relatively high agreement between readers for anal fin spines (84%) and dorsal fin spines (81%) suggested the structures were relatively precise. However, age estimates from anal fin spines and dorsal fin spines exhibited low concordance with true ages. Although use of sagittal otoliths is a lethal technique, this method will likely remain the standard for aging Largemouth Bass and other similar black bass species. Introduction Effective fisheries management requires an understanding of population demo- graphics (e.g., age structure) and dynamics (i.e., recruitment, growth, mortality) (Ricker 1975). The ability to confidently and accurately estimate the age of fishes is critical for understanding how fish populations function and respond to manage- ment actions (Quist et al. 2012). Traditionally, scales were the preferred structure used to age Micropterus spp. (black basses), but recent studies have shown them to be inaccurate (Boxrucker 1986, Erikson 1983, Maceina and Sammons 2006, Welch et al. 1993). Sagittal otoliths have become the preferred aging structure for black basses in North America because they have been shown to provide accurate and precise age estimates (Buckmeier and Howells 2003, Heidinger and Clodfel- ter 1987, Hoyer et al. 1985, Maceina et al. 2007, Taubert and Tranquilli 1982). However, otoliths require sacrificing fish, a practice that may not be permissible 1 Idaho Cooperative Fish and Wildlife Research Unit, Department of Fish and Wildlife Sci- ences, University of Idaho, Moscow, ID 83844. 2 Georgia Department of Natural Resources, PO Box 2089, Waycross, GA 31052. 3 US Geological Survey, Idaho Cooperative Fish and Wildlife Research Unit, Department of Fish and Wildlife Sciences, University of Idaho, Moscow, ID 83844. * Corresponding author - klei7686@vandals.uidaho.edu. Manuscript Editor: Benjamin Keck