North American Sturgeon Otolith Morphology

• Published in: Copeia Vol. 104; no. 1; pp. 260 - 266
• Main Authors: Chalupnicki, Marc A, Dittman, Dawn E
• Format: Journal Article
• Language: English
• Published: The American Society of Ichthyologists and Herpetologists 01.03.2016; American Society of Ichthyologists and Herpetologists
• Subjects: s; North America
• DOI: 10.1643/CI-14-076
• ISSN: 0045-8511

Accurate expedient species identification of deceased sturgeon (Acipenseridae) when external physical characteristic analysis is inconclusive has become a high priority due to the endangered or threatened status of sturgeon species around the world. Examination of otoliths has provided useful information to aid in population management, age and size-class analysis, understanding predator–prey interactions, and archeological research in other fish species. The relationship between otolith characteristics and sturgeon species has remained unknown. Therefore, we analyzed the shape of otoliths from the eight species of sturgeon found in North America to test the utility of otolith characteristic morphology in species identification. There were distinct differences in the size and shape of the otoliths between species of sturgeon with little shape variation among individuals of the same species. The relationship between otolith length axes was linear, and most of the variability was explained by a Log (axis + 1) transformation of the x and y axes (r2 = 0.8983) using the equation y = 0.73x + 0.0612. Images of otoliths from all eight North American species are presented to assist in the identification process.