Date of Award


Document Type


Degree Name

Master of Science


Percina notogramma montuosa is described from 50 specimens taken in the tributaries of the upper James River. It is best separated from Percina notogramma notogramma, which inhabits the lower James, Rappahannock, York, Potomac and Patuxent rivers, on the basis of lateral-line scales (average difference 89%) and scales around the caudal peduncle (average difference 79%). A comparison of the meristic indices resulted in an average difference of 89%. A total of 18 out of 31 meristic and proportional characters were found to give significant differences.

The relatively few specimens from the Rappahannock, Potomac and Patuxent rivers precluded an intensive investigation of intrasubspecific variation but the data indicate that each river system represents a genetically isolated population cut off from its neighboring population by Chesapeake Bay.

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