Date of Award


Degree Name

Biological Sciences


College of Science

Type of Degree


Document Type


First Advisor

Thomas G. Jones

Second Advisor

Michael Little

Third Advisor

Charles Somerville


The blacknose dace species complex (Rhinichthys atratulus, Rhinichthys obtusus obtusus, and Rhinichthys obtusus meleagris) are among the most common freshwater fishes in eastern North American. Despite this fact, the taxonomy of this group is still in question. This study focuses on the relationship of the members of this species complex along an unusually large zone of contact in the high Appalachian Mountains of West Virginia. Morphological, distributional, and molecular analysis of the relationships of this complex were conducted in this area to try to shed light on the systematics of this group. Morphological analysis of coloration patterns of nuptual males displayed a strong division between the different forms and suggested that width of coloration of the side of the body, coloration of lateral line stripe, coloration below Lateral Line Stripe, and pectoral fin nuptual pad coloration were the strongest characters in determining the assignment of the individuals to the respective subspecies. Analysis of the distribution of the subspecies revealed a large number were found in drainages outside of their predicted range and in three instances, more than one form existed in a single waterbody. When the pre-Pleistocene distribution was applied to the present drainage, nearly all instances of anomalous distribution or the presence of multiple forms were explained. Molecular analysis of mitochondrial cytochrome b gene revealed a strong division between the eastern and western forms and showed evidence of an intermediate form from streams that were subject to stream capture events. Use of coloration patterns proved effective for differentiating between the subspecies and agreed with mitochondrial DNA based clusters, in West Virginia populations but caution must be used in areas where stream capture or interbasin transfer may have occurred.


Rhinichthys atratulus - West Virginia.

Rhinichthys atratulus - Morphology.