Evaluation of Three Aging Techniques and Back-Calculated Growth for Introduced Blue Catfish from Lake Oconee, Georgia

• Published in: Southeastern naturalist (Steuben, Me.) Vol. 14; no. 4; pp. 740 - 756
• Main Authors: Homer, Michael D., Peterson, James T., Jennings, Cecil A.
• Format: Journal Article
• Language: English
• Published: Humboldt Field Research Institute 01-12-2015; Eagle Hill Institute
• Subjects: catfish; fisheries; gillnets; Ictalurus furcatus; lakes; linear models; otoliths; Georgia
• ISSN: 1528-7092; 1938-5412
• DOI: 10.1656/058.014.0417

Back-calculation of length-at-age from otoliths and spines is a common technique employed in fisheries biology, but few studies have compared the precision of data collected with this method for catfish populations. We compared precision of back-calculated lengths-at-age for an introduced Ictalurus furcatus (Blue Catfish) population among 3 commonly used cross-sectioning techniques. We used gillnets to collect Blue Catfish (n = 153) from Lake Oconee, GA. We estimated ages from a basal recess, articulating process, and otolith cross-section from each fish. We employed the Frasier-Lee method to back-calculate length-at-age for each fish, and compared the precision of back-calculated lengths among techniques using hierarchical linear models. Precision in age assignments was highest for otoliths (83.5%) and lowest for basal recesses (71.4%). Back-calculated lengths were variable among fish ages 1–3 for the techniques compared; otoliths and basal recesses yielded variable lengths at age 8. We concluded that otoliths and articulating processes are adequate for age estimation of Blue Catfish.