Comparing Precision of Otolith and Pectoral Spine Age Assessments for Black and Yellow Bullheads

Despite the broad geographical range of bullhead catfishes (Ameiurus spp.), their population vital rates have rarely been studied. Estimation of vital rates requires accurate age estimates and otoliths generally are considered to be the most accurate and precise aging structure for most fish species. However, pectoral spines of some ictalurid species have been used to generate precise age estimates of younger fish. Although previous studies have compared age estimates between otoliths and spines for large-bodied, longer-lived catfishes, there have been few comparable studies for bullheads. Our objectives were to compare the reader precision and preparation times of lapilli otoliths and pectoral spines (articular process [AP] and basal recess [BR] sections) to determine which aging structure is most precise and efficient for age analysis of black bullhead (Ameiurus melas) and yellow bullhead (A. natalis). During 2020 we collected 116 black bullhead from River Chase Pond and 106 yellow bullhead from Prague Lake, Oklahoma. Between-reader precision and agreement were higher for lapilli otoliths than the AP and BR sections in both species. As age estimates increased, the AP and BR underestimated ages compared to otoliths in both species. Estimates of von Bertalanffy growth parameters and mortality derived from pectoral spine sections and otoliths differed among structures, with faster growth and higher mortality estimated by spines relative to otoliths. The BR section took the least amount of time to prepare compared to the AP and otoliths but was the least precise. These results suggest that managers should use lapilli otoliths to estimate ages of black bullhead and yellow bullhead.