Bias, Precision, and Processing Time of Otoliths and Pectoral Spines Used for Age Estimation of Channel Catfish
Tony J. Barada, Aaron J. Blank, and Mark A. Pegg
Abstract.—Otoliths and pectoral spines are common calcified structures used to age channel catfish Ictalurus punctatus. Several studies have assessed accuracy and precision of these structures; however, results have been conﬂicting. Additionally, information on processing times required to prepare and assign ages to these structures is lacking. Therefore, our objective was to assess bias, precision, and processing time of otoliths and pectoral spines used for age estimation of channel catfish. Otoliths (N = 603) and spines (N = 3,397) were collected from channel catfish during 2007–2009 to assess bias and precision. A subsample of these structures was used to estimate and compare processing times. Otoliths displayed greater precision and less reader bias compared to pectoral spines. Age-specific bias was observed for pectoral spines in relation to otoliths, with pectoral spines greatly underestimating ages for age-11 and older channel catfish. Total processing time was greater for otoliths (12.26 min ± 1.09 [SE]) compared to pectoral spines (11.01 min ± 0.07 [SE]). These results provide managers with information to make decisions on which structure to use for age estimation of channel catfish given a known bias and precision desired for statistical analyses and amount of time allotted for the aging process.