Ontogenetic and Comparative Morphology of Clinch Dace (Chrosomus sp. cf. saylori)

Clinch Dace (Chrosomus sp. cf. saylori) is a rare species of minnow with fragmented populations occurring in the upper Clinch River watershed in Virginia. Major morphological and life history characteristics have not been described for Clinch Dace, and evidence that Clinch Dace is a new species is largely anecdotal. Here, we compare Clinch Dace morphometric and meristic characteristics to those of closely related congeners and test for sexual and ontogenetic changes in morphology. We also determined diet preference through gut content analysis. We conclude that Clinch Dace are morphologically distinct from congeners, and that there are changes in morphology attributable to sex and ontogenetic development. This study suggests that Clinch Dace is a distinct species, and isolation of Clinch Dace from congeners has led to distinct, measurable differences in morphology. Furthermore, digestive anatomy of Clinch Dace combined with a diet high in macroinvertebrates suggests that Clinch Dace occupy a trophic niche that is atypical for Chrosomus.