Gauley River Fishes 75 



ZOOGEOGRAPHY 



This survey established many distributional records. The remoteness of 

 the drainage and its inaccessibility, particularly in the lower two-thirds of 

 the main-stem and its tributaries, has undoubtedly been a deterrent to 

 sampling. The upper New River is generally more accessible. Perhaps for 

 this reason, students of West Virginia fishes have tended to avoid the 

 Gauley in their efforts. 



The confluence of Gauley and New rivers forms Kanawha River above 

 Kanawha Falls, long considered to be a barrier to upstream dispersal of 

 fishes. All the endemic forms of the upper Kanawha (New) drainage oc- 

 cur in the Gauley, exluding Etheostoma kanawhae which is not known from 

 West Virginia. However, the presence of six species found in Gauley 

 River in this survey and not previously reported from the upper Kanawha 

 drainage infers a relationship of the Gauley with the lower Kanawha 

 drainage. The new distributional records indicate that either Kanawha 

 Falls was not as effective a barrier as supposed, or conditions were once 

 more favorable than at present for the dispersal of fishes above the Falls 

 into Gauley River. In either case, it is assumed that other physical 

 barriers were effective in limiting dispersal of fishes into the upper New 

 River system. The zoogeographic relationships summarized below are 

 discussed in detail by Hocutt (in press). 



The wide distribution of Etheostoma nigrum in the Gauley drainage sup- 

 ports a hypothesis that more favorable conditions once existed for fishes 

 to negotiate Kanawha Falls. It is more often found in slack water habitats 

 over sand and detritus, and avoids strong currents. Thus, we reason that 

 it is not a recent migrant over Kanawha Falls. Cole (1971) supports this, 

 postulating that the present E. nigrum distribution resembles that of pre- 

 Pleistocene times, and that populations east of the Appalachians are a 

 consequence of relatively recent stream capture. 



Subsequent to the Tertiary uplift of the Appalachians, the Teays River 

 had a cutting advantage due to its volume and gradient. The evolving 

 (New River) gorge with its multitude of rapids and cataracts probably 

 served as an effective barrier. Kanawha, Wylie, Bull and Sandstone Falls 

 are remnants of that rejuvenated period (Hocutt et al. 1978). Prior to re- 

 cent impoundment, Kanawha Falls was the first of the series of natural 

 barriers that served as a faunal filter (Hocutt in press). 



The Pleistocene (Neff et al. 1970; Hocutt et al. 1978) impoundment of 

 Teays River would have inundated Kanawha Falls if indeed the Falls ex- 

 isted at that time. Gauley River, smaller in drainage and volume of water, 

 cut its gorge more slowly than the Teays and offered a route of dispersal 

 for fishes (Hocutt, in press). Many species present today serve as relict 

 populations to that time. The large numbers of Etheostoma caeruleum 



