Article (Online ahead of print)
Snorkel observations of Percina roanoka and P. nevisense in the Roanoke River during summer months were followed by measuring current velocity, water depth, and substrate diameter at points of occupation. A total of 89 observations of P. roanoka and 81 observations of P. nevisense were compared using two-sample T-tests. Percina roanoka inhabited faster, shallower water than P. nevisense with the former found in a mean flow of 0.318 m/s and depth of 31.53 cm and the latter in a mean flow of 0.17 m/s and depth of 55.6 cm. Mean diameter of substrate at points of occupation did not differ significantly between the two species with P. roanoka over substrate 10.14 cm diameter, and P. nevisense over substrate of 9.7 cm diameter. Differences in habitat among age classes were not detected for either species. These findings suggest habitat partitioning along current velocity and depth help maintain the diverse darter assemblage in the Roanoke River.
Spruill, D. R., & Powers, S. L. (2019). Microhabitat comparison of Percina roanoka (Roanoke Darter) and Percina nevisense (Chainback Darter) in the Roanoke River. Virginia Journal of Science, 70(1/2), 7 pp. Online ahead of print. doi:10.25778/rvvv-j156