Abstract
The objectives of this study were to characterize relationships between water and paddlefish Polyodon spathula dentary Sr:Ca, δ 18 O and stable hydrogen isotope ratio ( δ D ) to determine the accuracy with which individual P. spathula could be assigned to their collection locations using dentary‐edge Sr:Ca, δ D and δ 18 O . A laboratory experiment was also conducted to determine whether dentary Sr:Ca in age 0 year P. spathula would reflect shifts in water Sr:Ca to which fish were exposed. Significant linear relationships between water and dentary Sr:Ca, δ D and δ 18 O were observed, although the relationship between water and dentary δ 18 O was weaker than those for Sr:Ca and δ D . Classification success for individual fish to collection locations that differed in water Sr:Ca, δ D and δ 18 O ranged from 86 to 100% based on dentary‐edge Sr:Ca, δ D and δ 18 O . Dentary Sr:Ca increased significantly in laboratory‐reared age 0 year P. spathula following 4 weeks of exposure to elevated water Sr:Ca; dentary Sr:Ca of fish held in water with elevated Sr:Ca was also significantly higher than that of control fish reared in ambient laboratory water. Results indicated that P. spathula dentaries reflect water signatures for commonly‐applied natural chemical markers and strongly suggest that dentary microchemistry and stable‐isotopic compositions will be applicable for reconstructing P. spathula environmental history in locations where sufficient spatial differences in water chemistry occur.