Ichthyology

The Mimic Shiner (Notropis volucellus) is a small, silvery, North American minnow with a wide geographic distribution that includes portions of the Mississippi River, Great Lakes, Hudson Bay, Gulf of Mexico, and several Atlantic Coast drainage basins. As currently classified, the Mimic Shiner has long been thought to contain multiple undescribed, morphologically similar species but, to date, little research has been performed to determine the identity, geographic distribution, and evolutionary relationships of these cryptic species, which has been called “one of the most interesting, needed, and difficult problems remaining in the systematics of North American freshwater fishes” (Etnier and Starnes 1993, p. 233). In New York, this species has a curious distribution, with populations being found in the northeastern watersheds of the Saint Lawrence River Basin and the southwestern watersheds of the Ohio River and Great Lakes watersheds, but nowhere in between. Our examinations of specimens deposited in the NYSM Ichthyology collection have uncovered several differences in morphology (particularly in pigmentation patterns) between these populations. In order to fully demonstrate the distinctiveness of these populations and determine their evolutionary and geographical origins, we have begun an examination of this species complex throughout its entire range, which includes both classical morphological methods and molecular phylogenetic analyses based on mitochondrial and nuclear DNA sequences. We anticipate this work to result in the description of several new species in the coming years, as well as an increased understanding of the interspecific and intrageneric evolutionary relationships of this perplexing group of minnows.