Precision of Hard Structures Used to Estimate Age of Bowfin in the Upper Mississippi River

Abstract

The bowfin Amia calva has traditionally been considered a nuisance species that competes for resources with more desirable fish species. However, an emerging market for bowfin roe has increased the species' economic importance and raised awareness associated with the lack of information on its ecology and population dynamics. Furthermore, few studies have investigated the utility and precision of hard structures used to estimate bowfin age. The objective of this study was to examine the precision of age estimates obtained from sectioned pectoral fin rays, otoliths, scales, gular plates, and branchiostegal rays of bowfin collected from the upper Mississippi River. Structures from 255 bowfin were examined. Otoliths, scales, and branchiostegal rays were excluded from analyses because of poor readability. Sectioned pectoral fin rays provided the highest between-reader agreement and lowest variation between age estimates.