Quantifying Morphology of Cyprinella lutrensis x C. venusta Hybrids in Missouri

Christopher M. Hockaday^1,* and Aaron D. Geheber¹

¹University of Central Missouri, School of Natural Sciences, Warrensburg, MO 64093. *Corresponding author.

Southeastern Naturalist,Volume 19, Issue 4 (2020): 692–708

Abstract
Non-native Cyprinella venusta (Blacktail Shiner) are known to occur in Truman Reservoir in Missouri. In 2017, we documented hybridization between C. venusta and native C. lutrensis (Red Shiner) within the reservoir. The goal of this study was to quantify hybrid morphology relative to the 2 parent species. We examined meristic relationships among individuals based on 4 different counts including: lateral line scale number, anal fin ray number, below lateral line scale rows, and circumferential scale rows. We also gathered geometric morphometric data, based on 14 homologous landmarks, from both hybrid and parent individuals. We then used principal component analysis to describe and visualize body shape variability among individuals, and ran ANOVA using principal component scores to test for body shape differences among hybrid and parent species. Meristic data displayed greater similarity between hybrid and C. venusta individuals compared to that of hybrid and C. lutrensis individuals. Geometric morphometric analyses determined that hybrid individuals were between C. lutrensis and C. venusta in morphospace. Hybrid individual shape was significantly different from both parent species, and this distinction was mainly driven by an intermediate body depth in hybrids. These results compliment findings of previous genetic research that was conducted on C. lutrensis x C. venusta hybrids but lacked full morphological comparisons.

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