Document Type

Original Research Article


The topminnow species Fundulus notatus and F. olivaceus have broadly overlapping geographic distributions that extend throughout much of the central and southern United States. In the northern portion of their respective ranges, in Missouri, the regional distributions of the two species coincide largely with recognized ecoregions. In the unglaciated southern half of Missouri, F. olivaceus is distributed throughout Ozark upland habitats while F. notatus is abundant in marginal large river and prairie habitats along the Ozark borders. An exception to this partitioning is the historical report of abundant F. notatus in the Bourbeuse and upper Meramec River drainages within the Ozark uplands ecoregion. We conducted an extensive survey of the Bourbeuse and Dry Fork Meramec Rivers to determine topminnow species composition in these systems. Our surveys found abundant F. olivaceus populations throughout these drainages and failed to uncover any F. notatus individuals. A review of museum accessions from the 1940s and 1960s confirms the historical presence of F. notatus in these river drainages, suggesting that a significant shift in topminnow species abundance has occurred in the past half century.



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.