Date of Award


Degree Name

Biological Sciences


College of Science

Type of Degree


Document Type


First Advisor

Thomas G. Jones

Second Advisor

Thomas K. Pauley

Third Advisor

James B. Spence


The Maryland darter has not been observed since 1988. Historic populations were located in Deer Creek, Swan Creek, and Gashey’s Run all of which occur in the lower Susquehanna drainage. At these locations, specimens were collected or observed at the lowest riffle of the stream. Some researchers suggest this may be a large river darter. The Conowingo Dam complicates surveying below the facility due to the rapid fluctuations in water levels caused by regulation for power production. Surveying efforts included trawling in the mainstem, and visual surveys in the mainstem, and searching/sampling all historically known locations of Etheostoma sellare. During this study 153 Benthic trawls totaling 272.4 minutes of bottom time yielded no Maryland darters. Also 10,452 fish were collected from 4 tributary sites (3 historic and 1 new) yielding no Maryland Darters. In addition, during 307.1 man-hours of visual surveys no Maryland darters were observed. Considering the data from this study it is apparent that the Maryland darter has declined within its historical range. However, habitat assessment of new sites showed that habitat similar to E. sellare’s historical habitat still exists in the Susquehanna mainstem and tributaries. Additional surveys are needed to determine if the Maryland darter is extant.


Darters (Fishes)




Fishes - Susquehanna River