Nesticus canei, 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 canei sp. nov.

Fig. 40A-D

Material examined.

Type material: Holotype: USA - North Carolina, Yancey Co. • holotype ♂; Hwy 19W along Cane River , near Egypt-Ramseytown Fire Station , near Lewisburg ; 35.9921°N, - 82.3927°W; 11 Aug. 2004; M. Hedin, R. Keith, J. Starrett, S. Thomas leg.; MCH 04_043 (SDSU_TAC000671) ; Paratypes: - Yancey Co. • ♂, ♀; Hwy 19W along Cane River , near Egypt-Ramseytown Fire Station , near Lewisburg ; 35.9921°N, - 82.3927°W; 11 Aug. 2004; M. Hedin, R. Keith, J. Starrett, S. Thomas leg.; MCH 04_043; Non type material: - Yancey Co. • 9♀, 17 imm; Hwy 19W along Cane River , near Egypt-Ramseytown Fire Station, near Lewisburg; 35.9921°N, - 82.3927°W; 11 Aug. 2004; M. Hedin, R. Keith, J. Starrett, S. Thomas leg.; MCH 04_043 .

Diagnosis.

The male palp is like that of Nesticus gertschi (Fig. 39A, B ) but the distal end of the tegular apophysis is acute rather than blunt, and the basal portion of median apophysis is relatively more expanded (Fig. 40A, B ). The distal paracymbial process lacks the subdistal processes as found in N. gertschi . Female with dorsal portion of internal anterior lobes/plates well sclerotized, rounded anteriorly and curving ventrally (Fig. 40C, D ).

Description of ♂ holotype

(SDSU_TAC000671). Carapace dusky cream to orange, conspicuous faint dark pigment behind ocular area, along carapace margin bleeding inwards. Legs pale yellow to cream. Abdomen mostly pale cream, with crisp 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 1.6, CW 1.3, abdomen length 2, total body length 3.6. Leg I total length 10.45 (3, 0.65, 3.1, 2.55, 1.15), leg formula 1423, leg I / CW ratio 8.0. Palp tegular apophysis with a 90-degree bend, distal end acute and blade-like. Lateral process of median apophysis concave, broadening and well-sclerotized along edge, distal process drawn into thin tip that closely parallels tegular apophysis tip. Paracymbium with strong ventral process, distal process consistent with species group (spatulate) and without other processes, dorsal process translucent blade of medium width, reaching above ventral process, weakly serrated at tip.

♂ Variation.

The palp of the paratype male is similar to the holotype.

Description of ♀ paratype

(SDSU_TAC000672). Carapace dusky cream, very faint dark pigment behind ocular area, along carapace margin bleeding inwards. Legs pale yellow to cream. Abdomen with paired, lateral darker marking on a dirty gray background. Eyes approximately equal in size, except for AMEs, ~ 1/4 width of ALEs. Eyes with rings of dark pigment. CL = 1.2, CW 1.05, abdomen length 1.55, total body length 2.75. Leg I total length 8.1 (2.3, 0.55, 2.3, 2, 0.95), leg formula 1423, leg I / CW ratio 7.7. Epigynum, viewed laterally, with a prominent nose-shaped, cream-colored median septum, like other members of the species group. Viewed dorsally, dorsal-projecting portion of internal anterior lobes well sclerotized, rounded anteriorly and curving ventrally. Sclerotization making these appear as dark circles sitting above epigynum when viewed ventrally. Viewed dorsally, spermathecae below epigynal pocket, angled obliquely upwards, approximately banana-shaped.

♀ Variation.

Adult females from the type locality vary in body size and in carapace and abdomen color (dark vs. light) but share a similar epigynum.

Distribution and natural history.

Known only from the type locality from along the Cane River, a tributary of the Nolichucky River. Adjacent collections have thus far only resulted in the collection of non-sister Nesticus templetoni (Fig. 30 ) and N. paynei further east (Fig. 13 ). We hypothesize that N. canei has a very small geographic distribution. More collecting effort in the immediate vicinity of the type locality is needed to understand the geographic extent of this apparently microendemic species.

Specimens from the type collection were found to be relatively common in void spaces beneath rocks in a small shaded boulderfield in roadside forest, at approximately 700 meters in elevation.

Etymology.

Named after the Cane River, a small north-flowing river found only in Yancey County, North Carolina.

Remarks.

Morphologically very similar to Nesticus gertschi and sister to this taxon on UCE trees (Figs 3 , 4 ). This species is of conservation importance because of an apparently naturally small geographic distribution.

Figures

Figure 3. UCE concatenated maximum likelihood tree. Distant outgroups removed (for graphical purposes), specimen numbers correspond to those in Suppl. material 3 (with detailed location provided in Suppl. material 1). Node numbers correspond to bootstrap (bold text) / gCF / sCF. Only bootstrap values below 100 shown, all others 100. gCF and sCF values rounded to nearest integer; sCF values below 38 highlighted with red text.

Figure 4. UCE ASTRAL species tree. Distant outgroups removed (for graphical purposes), specimen numbers correspond to those in Suppl. material 3 (with detailed location provided in Suppl. material 1). Included are quartet support values (rounded to nearest integer), and local posterior probability values (if less than 1.0, red text). Branch lengths in coalescent units for internal branches only, terminal branch lengths arbitrary. Internal branch to Nesticus cressleri truncated for graphical purposes.

Figure 13. Distribution of Nesticus tennesseensis group species. Type localities designated with yellow circles. State boundaries and major cities shown for geographic context. Dashed lines circumscribe known species distributions.

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 39. Nesticus gertschi and N. secretus genitalia. N. gertschi A North Carolina, Yancey Co., Blue Ridge Parkway at Balsam Gap, MCH 02 _ 195, ♂ palp, ventral B North Carolina, Buncombe Co., NW of Hickory Nut Gap, Hwy 74, MCH 01 _ 173, ♂ palp, ventral. North Carolina, Buncombe Co., NW of Hickory Nut Gap, Hwy 74, MCH 01 _ 173, epigynum, ventral (C), dorsal (D). North Carolina, Yancey Co., Blue Ridge Parkway at Balsam Gap, MCH 02 _ 195, epigynum, ventral (E), dorsal (F). Scale bar: 0.5 mm. N. secretus Gertsch 1984 epigynum. Tennessee, Great Smoky Mountains National Park, ♀ holotype, ventral (G), dorsal (H).

Figure 40. Nesticus canei sp. nov. genitalia. North Carolina, Yancey Co., Hwy 19 W, along Cane River, near Egypt-Ramseytown Fire Station, MCH 04 _ 043 (SDSU _ TAC 000671), ♂ palp, ventral (A), dorsal (B). North Carolina, Yancey Co., Hwy 19 W, along Cane River, near Egypt-Ramseytown Fire Station, MCH 04 _ 043 (SDSU _ TAC 000672), epigynum, ventral (C), dorsal (D). Scale bar: 0.5 mm.