52 



Fred C. Rohde, Mary L. Moser and Rudolf G. Arndt 



consider the dusky darter to have been extirpated from this state by unknown 

 causes. It appears to be a relatively tolerant species in other portions of its range. 



THREATENED SPECIES 



American brook lamprey, Lampetra appendix (DeKay) 



The American brook lamprey is widely distributed in the St. Lawrence 

 and Mississippi river basins from New York to northern Arkansas, and on 

 Atlantic Slope drainages from southern Quebec south to the Roanoke River 

 drainage in Virginia (Page and Burr 1991). In North Carolina it was known from 

 only one site in the downstream reach of Spring Creek, Madison County, at a 

 point where a railroad trestle crosses this creek, where 26 individuals were taken 

 in 1980 and 1 in 1983 (Menhinick 1986). We took one adult some 200 m down- 

 stream of the above site (and about 50 m upstream of the confluence of Spring 

 Creek with the French Broad River, Madison County) on 22 April 1995 (Fig. 6), 

 and two adults on the same day, also in Spring Creek at a point about 0.9 rkm 

 above this confluence. They were males and measured 144, 147, and 157 mm 

 TL. All were taken in gravel riffles where the current was 0.45 m/sec. We col- 

 lected one ammocoetes of 152 mm TL in a sandy-bottomed pool about 50 m 

 downstream of the last-mentioned Spring Creek site on 14 August 1994. The pH 

 here was 6.9, and the dissolved oxygen concentration was 8.4 ppm. This species 

 appears to be restricted to this creek in North Carolina. Its status of threatened 

 in North Carolina appears to be conservative. 



Fig. 6. Distribution of the American brook lamprey, Lampetra appendix, (circle) 

 and the striped shiner, Luxilus chrysocephalus, (star) in the French Broad and 

 Nolichucky river systems, North Carolina. Some symbols overlap sites. 



NORTH CAROLINA 



