Triodopsis juxtidens robinae, Hotopp, Kenneth P., 2015

Hotopp, Kenneth P., 2015, A new Triodopsis juxtidens subspecies (Gastropoda: Pulmonata) from West Virginia, U. S. A., Zootaxa 3914 (4), pp. 490-494 : 490-493

Triodopsis juxtidens robinae subsp. nov.

Type locality. Brush Creek Preserve, The Nature Conservancy, Mercer County, West Virginia, U.S.A.; on and in leaf litter on steep forested slopes of Brush Creek above its confluence with the Bluestone River.

Holotype. CM103371 , U.S.A. West Virginia, Mercer County, Brush Creek Preserve, Timothy A. Pearce, 1 October 2007. Shell ( Figure 1 ) on a steep rocky slope with a mixed eastern hemlock ( Tsuga canadensis L.(Carr.))-hardwood forest canopy, on the east side of Brush Creek above its confluence with the Bluestone River (within 10m of UTM, NAD83, 17S, 0 494625, 4147911).

Paratypes. CM97548, five shells from the west side of Brush Creek close to its confluence with the Bluestone River, Kenneth P. Hotopp and Brett Freedman, 3 August 2005; CM97549, five shells from mesic forest among cliffs on the west side of Brush Creek near the type locality, Kenneth P. Hotopp and Brett Freedman, 3 August 2005 (within 50m of UTM, NAD83, 17S, 0 494627, 4147741); CM 141101 , five shells from hardwood forest near a hillside spring at Pipestem State Park, Kenneth P. Hotopp and Kenneth R. Hotopp (Sr.), 19 September 2008 (within 50m of UTM, NAD83, 17S, 0 500316, 4152917); CM 141102 , five shells from mixed forest upon sandstone talus at Pipestem State Park, Kenneth P. Hotopp and Kenneth R. Hotopp (Sr.), 19 September 2008 ( Figure 3 ; within 50m of UTM, NAD83, 17S, 0 498866, 4154255); CM85754, one live specimen on a steep, wooded slope at the foot of a cliff above a ravine, east side of Brush Creek, Timothy A. Pearce and Alice W. Doolittle, 1 October 2007, (within 10m of UTM, NAD83, 17S, 0 494866, 4147454).

Additional material. Daniel C. Dourson, personal collection, 16 shells from cliffline at Brush Creek, Jeffrey J. Hajenga, 12 March, 2013; Daniel C. Dourson, personal collection, 16 shells from forest at Brush Creek, Jeffrey J. Hajenga, undated; Daniel C. Dourson, personal collection, 5 shells from forest at Sand Branch, Jeffrey J. Hajenga, 13 October, 2013; CM103371 , one immature shell from mixed forest, southeast side of junction of Brush Creek with Bluestone River, Timothy A. Pearce, 1 October 2007 (within 10m of UTM, WGS84, 17S, 0 494625, 4147911); CM85754, five broken shells from a steep, wooded slope at the foot of a cliff above a ravine, east side of Brush Creek, Timothy A. Pearce and Alice W. Doolittle, 1 October 2007 (within 10m of UTM, NAD83, 17S, 0 494866, 4147454).

Etymology. The subspecific name robinae is in honor of my wonderful wife, Mary “Robin” Robertson Gorrell, originally of Clarksburg, West Virginia, on the year of our 25th wedding anniversary.

Distribution. Forested slopes of the Bluestone River Valley and tributaries in Mercer and Summers Counties, West Virginia, U.S.A.

Description. Shell (Figures 1,2) 7.7mm tall (paratypes 7.0–9.0mm; measured from apex to lowest point on shell with axis vertical) x 14.7mm wide (paratypes 13.1–17.6mm; measured including the peristome), height:width 0.49 (paratypes 0.45–0.58); umbilicus open, 3.2mm wide (paratypes 2.3–4.2mm; measured at the whorl suture immediately behind the peristome to the suture on the farthest side of the umbilicus), umbilicus:width 0.20 (paratypes 0.17–0.24); whorls 5.2 (4.75–5.5; counted along a tangent starting parallel with the beginning of the apical suture, following Pilsbry [1939]); color light brown to reddish-brown. Protoconch and juvenile whorls with fine growth wrinkles, subsequent whorls with growth wrinkles and fine, regular ribs, approximately 3.5 ribs/mm (paratypes 3.5–4.5) on final quarter whorl; sculpture becoming minutely papillose, primarily at the suture and final whorl; final whorl inflated near the end, the suture rising upon the wall of the penultimate whorl, then abruptly descending and well-constricted behind the aperture. Aperture widely reflected, white, 7.5mm tall (outside distance, measured on plane of aperture; paratypes 5.9–7.8mm) x 8.5mm wide (outside distance, measured from columellar edge of basal peristome to farthest palatal limit; paratypes 6.8–9.1mm), broadly triangular (viewed in the plane of the aperture), with the triangle’s apex usually to the right of the point at which the peristome meets the body whorl, and widest below an imaginary horizontal midline; peristome slightly-to-moderately dished and projecting forward at the top edge, with parietal, basal and palatal lamellae, often nearly straight along its basal edge; a light parietal callus at the aperture. Parietal lamella narrow, slightly to strongly curved toward the palatal denticle, its umbilical end sometimes continuous with the basal peristome; palatal denticle variable, usually wide at the distal end but sometimes pointed, and pointing inward behind parietal lamella; interdenticular sinus usually a defined semicircle; basal denticle deeper than wide, set perpendicular to the aperture upon a horizontal buttress ( Figure 2 ), the buttress usually taller to the palatal side of the tooth. Body of animal gray with dorsal surface of upper tentacles darker.

Figures

FIGURE 1. Shell of Triodopsis j. robinae subsp. nov. holotype from Brush Creek, Mercer Co., West Virginia (CM 103371). Photographed by Charles F. Sturm.

FIGURE 2. View of the aperture and basal denticle of Triodopsis j. robinae subsp. nov. holotype (CM 103371). Photographed by Charles F. Sturm.

FIGURE 3. Comparison of seven Triodopsis species shells (left) to a series of six Triodopsis j. robinae subsp. nov. shells (right). The Triodopsis species representatives have similar shells to the new subspecies or are geographically near. To the left, from top to bottom, are: a, T. juxtidens, Durham, NC, 11 August 2008 (W. Frank, personal collection); b, T. juxtidens also from Durham Co., NC (H. G. Lee, personal collection); c, T. rugosa from Logan Co., WV (FMNH 264690); d, T. anteridon from Wyoming Co., WV (FMNH 264768); e, T. picea from Pocahontas Co., WV (FMNH 266426); f, T. pendula from Iredell Co., NC (FMNH 266352), and g, T. discoidea from Crawford Co., IN (H. G. Lee, personal collection). To the right are paratype h, Triodopsis j. robinae subsp. nov. from Brush Creek (CM 97548); paratypes i, j, Brush Creek (CM 97549; two shells); k, the holotype from Brush Creek (CM 103371); paratype l, Pipestem State Park (CM 141101); and paratype m, Brush Creek (CM 85754). Adapted from Frank and Lee (2014), with permission, and with photography of Triodopsis j. robinae subsp. nov. specimens by Charles F. Sturm.