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Roger F. Thoma

Publications and source records attributed to Roger F. Thoma.

5 recordsLinked to original sources
USGS2019

Cambarus fetzneri sp. nov., a new species of burrowing crayfish (Decapoda: Cambaridae) from the Allegheny Mountains of Virginia and West Virginia, USA

The disjunct distribution of Cambarus monongalensis has led to speculation about its taxonomic status. An Appalachian Plateau population occurs in northern and central West Virginia and Southwestern Pennsylvania, and a mountain population occurs in the Allegheny Mountains and Ridge and Valley physiographic provinces of the Virginias. Herein we describe the mountain population as Cambarus fetzneri sp. nov. The two species differ genetically and morphologically, and have different color patterns. Specifically, C. fetzneri sp. nov. chelae lack extensive red coloration on the distal end of the propodus and dactyl, possess rostral margins that lack any red coloration, compared to C. monongalensis , which has extensive red coloration on the dactyl and propodus, as well as red rostral margins. Morphologically, the rostrum of C. fetzneri sp. nov. is shorter and wider than that of C. monongalensis . Also, adult C. fetzneri sp. nov. are considerably smaller in body size than those of C. monongalensis .

Virginia, West Virginia↗
USGS2019

Cambarus loughmani, a new species of crayfish (Decapoda: Cambaridae) endemic to the pre-glacial Teays River Valley in West Virginia, USA

A new species of crayfish, Cambarus loughmani sp. nov., is described from the preglacial Teays River Valley of Cabell, Kanawha, Lincoln, Mason, and Putnam counties, West Virginia. The species was previously considered to be part of the Cambarus dubius complex. Loughman et al. restricted C. dubius to an orange colour morph found in central and northern portions of the Allegheny Mountains and Appalachian Plateau in central West Virginia, western Maryland, and south-central Pennsylvania. The new species described herein can be distinguished from all other members of Cambarus Erichson, 1846 by a double row of cristiform tubercles on the palm, an open areola with two rows of punctations, and a consistent blue colouration.

West Virginia↗
USGS2017

Cambarus (C.) appalachiensis, a new species of crayfish (Decapoda: Cambaridae) from the New River Basin of Virginia and West Virginia, USA

Cambarus ( Cambarus ) appalachiensis is a stream-dwelling crayfish endemic to the greater New River basins of Virginia and West Virginia. The new species is morphologically most similar to Cambarus sciotensis. Cambarus appalachiensis can be differentiated from C. sciotensis by its more elongated chelae which possess a single mesial row of tubercles, reduced to no tuberculation on the dorsal-longitudinal ridge of the dactyl, and reduced lateral impression. Cambarus sciotensis has a more subrectangular chelae with two rows of mesial margin tubercles on the chelae, as well as both a pronounced dorsal-longitudinal ridge and pronounced lateral impression. Several chelae meristic ratios also differentiate C. appalachiensis from C. sciotensis . Within the New, Gauley, and lower portions of the Greenbrier basins C. appalachiensis is the dominant tertiary burrowing Cambarus species, and as such, is considered stable across its range.

Virginia, West Virginia↗
USGS2013

Cambarus (C.) hatfieldi , a new species of crayfish (Decapoda:Cambaridae) from the Tug Fork River Basin of Kentucky, Virginia and West Virginia, USA

Cambarus ( Cambarus ) hatfieldi is a stream-dwelling crayfish that appears to be endemic to the Tug Fork River system of West Virginia, Virginia, and Kentucky. Within this region, it is prevalent in all major tributaries in the basin as well as the Tug Fork River’s mainstem. The new species is morphologically most similar to Cambarus sciotensis and Cambarus angularis. It can be differentiated from C. sciotensis by its squamous, subtrinagular chelae compared to the elongate triangular chelae of C. sciotensis ; its shorter palm length/palm depth ratio (1.9) compared to C. sciotensis (2.3); and a smaller areola length/total carapace length ratio (30.4% vs.36.5% respectively). Cambarus hatfieldi can be differentiated from C. angularis by its smaller areola length/total carapace length ratio (30.4% vs. 36.7% respectively); a smaller rostrum width/rostral length ratio (59.4% vs. 67.2% respectively); its rounded abdominal pleura as compared to the subtruncated pleura of C . angularis ; the length of the central projection and mesial process of C . hatfieldi which both extend to the margin of the gonopod shaft or slightly beyond the margin compared to the central projection of C. sciotensis and C. angularis where both extend well beyond the margin of the gonopod shaft.

Kentucky, Virginia, West Virginia↗