Unionid Mollusca (Bivalvia) from Little South Fork 



Cumberland River, with Ecological and 



Nomenclatural Notes 



Lynn B. Starnes 



Tennessee Valley Authority, 



450 Evans Building, Knoxville, Tennessee 37902 



AND 



Arthur E. Bogan 



Department of Malacology, 



Academy of Natural Sciences of Philadelphia, 



19th and the Parkway, Philadelphia, Pennsylvania 19103 



ABSTRACT— A mollusk survey of the Little South Fork of the 

 Cumberland River in southern Kentucky from 1977 to 1981 yielded 24 

 species of Unionidae, one species of Corbiculidae, and 5 species of 

 aquatic gastropods. Pertinent taxonomic notes on unionids are made 

 herein. A series of quantitative surveys in riffles in the lower third of 

 the river (an area designated a Kentucky Wild River) revealed average 

 unionid densities ranging from 2.87 to 7.53 individuals per square 

 meter. Approximately five percent of the river contains optimal riffle 

 habitat. Average corbiculid densities ranged from 10.75 to 46.59 indi- 

 viduals per square meter. 



INTRODUCTION 



The Little South Fork of the Cumberland River (herein referred to 

 as Little South Fork) originates in Pickett County, Tennessee, meanders 

 through the Interior Low Plateau physiographic province, and conflu- 

 ences with the Big South Fork of the Cumberland River approximately 

 110 stream kilometers (64 air km) from its source (Fig. 1) (Fenneman 

 1938). Little South Fork changes from a high gradient stream south of 

 the Kentucky-Tennessee border to a moderate gradient stream with well 

 developed riffles and increasingly larger pools downstream. 



Throughout its length little South Fork has eroded through Penn- 

 sylvanian shale and sandstone to Mississippian limestone. Water qual- 

 ity data reported by Harker et al. (1979, 1980) indicate that the Kidder 

 and Ste. Genevieve Limestone Members of the Monteagle Limestone, 

 exposed in the streambed, strongly influence water chemistry. 



Development within the Little South Fork watershed is limited and 

 approximately 65% of the drainage area forested (Harker et al. 1980.) 

 Agriculture is primarily limited to floodplains. The watershed in the 

 vicinity of Mt. Pisgah and Parmleysville has historically been and 

 remains an area of oil production. Harker et al. (1980) reported oil 

 slicks, and we noted hydrogen sulfide odors, in the river in this area. 

 Surface mining of coal deposits associated with the Breathitt Formation 



Brimleyana No. 8:101-119. December 1982 101 



