80 
Noel M. Burkhead, et al. 

t 
— 
NC 'X'l 
O Ictalurus platycephalus 
^Ictalurus brunneus 
/I 
vi' 
«0 hM 
30 Mi 
Fig. 1. Distribution of Ictalurus brunneus and I. platycephalus in the Roanoke 
River drainage, North Carolina and Virginia. 
regimes occur in many parts of these streams (Yerger and Relyea 1968). 
Extensive surveys of the Neuse drainage for Ictalurus, and less extensive 
surveys of other Carolinean Atlantic Slope drainages, revealed that I. 
brunneus is more abundant, sometimes greatly so, than /. platycephalus 
(M. Corcoran, pers. comm.). Corcoran also determined that, at least in 
the Neuse, both species are generally absent from the Coastal Plain. 
Thus, previous concepts of a preference by 7. brunneus for upper stream 
sections may partly relate to its numerical abundance over /. 
platycephalus. However, in the Roanoke drainage, only /. platycephalus 
appears to currently occur in the main trunk Roanoke system and the 
Smith River tributary of the Dan River. In both these systems it extends 
upstream well through moderate gradients into Blue Ridge foothills. 
The apparent absence of /. brunneus from most of the Roanoke 
drainage, including the Chowan system of the lower Roanoke, and the 
wide geographic and ecological range of /. platycephalus therein, suggest 
that /. brunneus was recently introduced to the Dan. Prior absence of /. 
brunneus would have allowed /. platycephalus to become widely es- 
tablished. The apparent current exclusion of /. brunneus from montane 
sections of the Dan system thus may relate to former establishment of /. 
platycephalus. 
Belews Lake, an upper Dan system impoundment (Fig. 1), was 
reportedly stocked with /. melas by a “concerned citizen” to improve 
fishing (W. Smith, pers. comm.). These introduced I. melas may have 
