Nesticus templetoni, Hedin & Milne, 2023

Hedin, Marshal & Milne, Marc A., 2023, New species in old mountains: integrative taxonomy reveals ten new species and extensive short-range endemism in Nesticus spiders (Araneae, Nesticidae) from the southern Appalachian Mountains, ZooKeys 1145, pp. 1-130 : 1

Nesticus templetoni sp. nov.

Figs 35A-H , 36A-J

Material examined.

Type material: Holotype: USA - Tennessee, Unicoi Co. • ♂ holotype; Rich Mountain, Clarks Creek ; 36.1457°N, - 82.5278°W; 10 Aug. 2004; M. Hedin, R. Keith, J. Starrett, S. Thomas leg.; MCH 04_036 (SDSU_TAC000669) ; Paratypes. - Tennessee, Unicoi Co. • ♂, ♀; Rich Mountain, Clarks Creek ; 36.1457°N, - 82.5278°W; 10 Aug. 2004; M. Hedin, R. Keith, J. Starrett, S. Thomas leg.; MCH 04_036; Non type material : - North Carolina, Madison Co. • ♂, 2♀; East Prong Hickory Fork Creek, off Hwy 212; 35.999°N, - 82.7033°W; 21 Aug. 2001; M. Hedin, M. Lowder leg.; MCH 01_144 ; - North Carolina, Yancey Co. • ♀; E Spivey Gap, Hwy 19W, along Big Creek, NW of Sioux; 36.0342°N, - 82.4043°W; 21 Aug. 2001; M. Hedin, M. Lowder leg.; MCH 01_146; • 4♂, 2♀; Scronce Creek Road, W of Bee Log; 35.9805°N, - 82.4245°W; 22 Oct. 2012; M. Hedin, J. Bond, F. Coyle leg.; MCH 12_141 ; - Tennessee, Greene Co. • 2♂, 6♀; Bald Mountain Road, NW Camp Creek Bald ; 36.0284°N, - 82.7253°W; 10 Aug. 2004; M. Hedin, R. Keith, J. Starrett, S. Thomas leg.; MCH 04_038; • 7♀, 10 imm; Bald Mountains, E Greystone Mountain , Round Knob Road; 36.0799°N, - 82.6859°W; 10 Aug. 2004; M. Hedin, R. Keith, J. Starrett, S. Thomas leg.; MCH 04_037 ; - Tennessee, Unicoi Co. • ♂, 2♀; along Mill Creek, Mill Creek Road on Rich Mountain, NE of Ernestville; 36.1018°N, - 82.4859°W; 22 Aug. 2007; M. Hedin, M. McCormack, S. Derkarabetian leg.; MCH 07_147; • 13♀, 3 imm; Rich Mountain , Clarks Creek ; 36.1457°N, - 82.5278°W; 10 Aug. 2004; M. Hedin, R. Keith, J. Starrett, S. Thomas leg.; MCH 04_036 .

Diagnosis.

In comparison to its sister species Nesticus brimleyi (see above), males of N. templetoni can be diagnosed by a shortened tegular apophysis (of variable shape) with a small, sclerotized extension lying behind the lateral process of the median apophysis, and never possessing all three medial paracymbial processes (Fig. 35A-H ). The epigynum is very similar to that of N. brimleyi , with epigynal pockets in the latter generally more circular with stronger lateral hoods (Fig. 34A-H ).

Description of ♂ holotype

(SDSU_TAC000669). Carapace cream-colored, very faint pigment in ocular area. Legs pale yellow to cream. Abdomen mostly pale cream, faint paired lateral pigmentation blotches. All eyes approximately equal in size, except for AMEs, ~ 1/4 width of ALEs. Eyes with rings of dark pigment. CL 1.25, CW 1.1, abdomen length 1.6, total body length 2.85. Leg I total length 9.85 (2.75, 0.5, 3, 2.6, 1), leg formula 1423, leg I / CW ratio 9.0. Palp with shoe-shaped tegular apophysis, with small dark sclerotized extension lying behind lateral process of median apophysis. Lateral process of median apophysis itself concave, broadening and well-sclerotized along edge, distal process drawn into thin tip. Ventral process of paracymbium translucent and triangular, distal process spatulate (consistent with species group), dorsal process wide at base, translucent, relatively short. Short, dark, conspicuous ventromedial process (Fig. 35A ).

♂ Variation.

Extensive population-level variation is seen in the male palps across relatively short geographic distances in this species. This includes variation in the shape of the shoe-shaped tegular apophysis and the sclerotized extension, the presence and shape of the paracymbial ventromedial and distomedial processes, and the shape of the dorsal paracymbial process (Fig. 35A-H ). Mill Creek males approximate type males (Fig. 35D, E ). Western Bald Mountain Road males possess a dorsal process that is nearly square in shape and includes a unique distal spike, with both ventromedial and distomedial paracymbial processes (Fig. 35C ). Northwestern Hickory Fork Creek males only possess a distomedial paracymbial process (Fig. 35F, G ). Southern Scronce Creek males lack ventro- and distomedial processes altogether and possess a dorsal process that is particularly wide at the base with a unique basal sclerotized extension (Fig. 35H ), perhaps representing a dorsomedial process that has migrated to the edge of the paracymbium.

Description of ♀ paratype

(SDSU_TAC000670). Carapace color as in male. Legs pale yellow to cream. Abdomen with paired, lateral darker markings on dirty gray background. Eye development as in male, eyes with rings of dark pigment. CL 1.3, CW 1.25, abdomen length 1.8, total body length 3.1. Leg I total length 10.75 (3, 0.75, 3.1, 2.7, 1.2), leg formula 1423, leg I / CW ratio 8.6. Epigynum, viewed laterally, with a prominent nose-like cream-colored median septum, like other members of the species group. Viewed ventrally, oval-shaped epigynal pockets lateral to median septum, angled outwards from top to bottom. Dorsal view showing spermathecae below epigynal pockets, angled upwards obliquely, approximately avocado-shaped. With sac-shaped structures anterior to epigynal pockets, hypothesized as vulval pockets (Vp). Epigynal plates meeting along midline, parallel from top to bottom.

♀ Variation.

Variation exists in the shape of the lateral epigynal pockets (ventral view), but the overall vulval pocket morphology, spermathecal shape, and parallel epigynal plates is fairly conserved across populations (Fig. 36A-J ).

Distribution and natural history.

Populations have been collected from the larger Bald Mountains area along the North Carolina / Tennessee border, southwest of Erwin, Tennessee (Fig. 30 ). Most populations have been collected from boulderfield void spaces. For example, at the type locality, spiders were found to be “common” in a "deep, moist boulderfield". At Bald Mountain Road (MCH 04_038) spiders were found near and under rock accumulations adjacent to a small stream.

Etymology.

This species is named to recognize and honor Dr. Alan Templeton, Charles Rebstock Professor Emeritus of Biology, Washington University. A brilliant evolutionary, speciation, and conservation biologist, with a deep love for all biodiversity. PhD dissertation advisor of MH, honored here for his inspiration and support during the first author’s formative years as an evolutionary biologist.

Remarks.

Two strongly supported geographic subclades are recovered with mitochondrial data (Fig. 6 ), corresponding to eastern / southern (Clarks Creek, Mill Creek, Scronce Creek) versus western (Bald, Bald Mtn Road, Hickory Fork) sample locations (Fig. 30 ). Increased nuclear phylogenomic sampling might ultimately reveal these geographic populations as reciprocally monophyletic.

Figures

Figure 6. COI IQT gene tree. Distant outgroups trimmed. Specimen numbers correspond to those in Suppl. material 3 (with detailed location provided in Suppl. material 1). Sequences from UCE capture denoted with " NODE ". Populations with a " Nesticus cooperi - like " male paracymbium denoted by small circles. Not all tip bootstrap values shown (see Suppl. material 4 for. tre file with all bootstrap values).

Figure 30. Distribution of Nesticus nasicus group species. Type localities designated with yellow circles. Primary cities shown for geographic context. Dashed lines circumscribe known species distributions; possible distribution of Nesticus secretus is tentative, see text for details.

Figure 34. Nesticus brimleyi epigynal variation. North Carolina, Rutherford Co., SE side of Rumbling Bald Mountain, MCH specimen # 1254, ventral (A), dorsal (B). North Carolina, Henderson Co., W of Bat Cave, MCH 07 _ 134, ventral (C), dorsal (D). North Carolina, McDowell Co., headwaters of Crooked Creek, MCH 07 _ 135, ventral (E), dorsal (F). North Carolina, Henderson Co., Newberry Creek, MCH 04 _ 075, ventral (G), dorsal (H). Scale bar: 0.5 mm.

Figure 35. Nesticus templetoni sp. nov. ♂ palps. North Carolina, Unicoi Co., Rich Mountain, Clark Creek, MCH 04 _ 036 (SDSU _ TAC 000669), dorsal (A), ventral (B) C Tennessee, Greene Co., Bald Mountain Road, MCH 04 _ 038, dorsal. Tennessee, Unicoi Co., along Mill Creek, MCH 07 _ 147, dorsal (D), ventral (E). North Carolina, Madison Co., East Prong Hickory Fork Creek, MCH 01 _ 144, dorsal (F), ventral (G). North Carolina, Yancey Co., Scronce Creek Road, MCH 12 _ 141, dorsal (H). Scale bar: 0.5 mm.

Figure 36. Nesticus templetoni sp. nov. epigynal variation. North Carolina, Unicoi Co., Rich Mountain, Clark Creek, MCH 04 _ 036 (SDSU _ TAC 000670), ventral (A), dorsal (B). North Carolina, Madison Co., East Prong Hickory Fork Creek, MCH 01 _ 144, ventral (C), dorsal (D). Tennessee, Greene Co., Bald Mountains, MCH 04 _ 037, ventral (E), dorsal (F). Tennessee, Unicoi Co., along Mill Creek, MCH 07 _ 147, ventral (G), dorsal (H). North Carolina, Yancey Co., E of Spivey Gap, MCH 01 _ 146, ventral (I), dorsal (J). Scale bar: 0.5 mm.