Nesticus jemisinae sp. nov.

Fig. 9A-D

Material examined.

Type material: Holotype: USA - Tennessee, Marion Co. • ♂ holotype; Rainbow Cave (TMN20); 20 Oct. 2021; K.S. Zigler leg.; SDSU_TAC000662 ; Paratypes: • ♀ paratype; data as for holotype; SDSU_TAC000663; • ♂, 2♀ paratypes; data as for holotype; SDSU_TAC000664; Non type material: - Marion Co. • ♀; Rainbow Cave (TMN20); 10 Nov. 2013; K.S. Zigler leg. ; KSZ 14-248. • 5 imm; Rainbow Cave (TMN20); 20 Oct. 2021; K.S. Zigler leg.

Diagnosis.

Easily distinguished from other members of the Nesticus archeri group. Distinctly small-bodied Nesticus jemisinae possesses well-developed eyes, different from the eyeless N. cressleri and N. stygius . Males possess a relatively simple paracymbium, contrasting with the multiple apophyses of the complex paracymbium of N. archeri (Fig. 10A) and N. pecki (Hedin and Dellinger 2005: figs 17, 18). The distinctive tegular apophysis is dark and sinuous, extending under the median apophysis. Female N. jemisinae may also be distinguished from the latter species by the epigynum. The epigynum of N. archeri is subtriangular with large anterior fovea and a narrow median septum (Fig. 10B, C), N. pecki possesses a broad posteriorly-broadening median septum (Fig. 11A-C), and N. jemisinae possesses a posteriorly-pointed median septum with the spermathecae expanded into small bulbs distally (Fig. 9C, D).

Description of ♂ holotype

(SDSU_TAC000662; Fig. 9A, B). Carapace and appendages are a dusky yellow. Abdomen mottled gray with darker patches between lighter parts. Eyes ringed with black and equally well-developed except for AME, which are significantly reduced. Carapace 1.18 long, 1.09 wide. Total body length 2.43. Leg I total length 9.50 (2.74, 0.46, 2.73, 2.56, 1.01), leg I / CW ratio 8.72, leg formula 1423. Paracymbium of palp relatively simple with a large proximally directed ventral process and a dark sinuous distal process. Dorsal process of paracymbium largely reduced to a shallow pocket on the distal edge. Palp tegular apophysis dark, long, narrow, pointed, and extends under median apophysis. Median apophysis elongated towards base of palp and angled proximally at tip.

♂ Variation.

No significant genitalic variation was noted in the material examined.

Description of ♀ paratype

(SDSU_TAC000663; Fig. 9C, D). Color of carapace, appendages, and abdomen as in male. Eyes as in male. CL 1.20, CW 0.97. Total body length 2.61. Leg I total length 7.96 (2.30, 0.44, 2.29, 1.98, 0.95), Ieg I / CW ratio 8.21, leg formula 1423. Epigynum width approximately half the width of the abdomen. Median septum pointed posteriorly and flanked by fovea along posterior margin. Internal foveal pockets visible from ventral inspection without dissection extending anteriorly angled outwards. Thin, elongate spermathecae curve slightly on outside margins of epigynum, extending anteriorly beyond foveal pockets, expanded into small bulbs distally.

♀ Variation.

No significant genitalic variation was noted in the material examined.

Distribution and natural history.

Known only from Rainbow Cave, located near Pocket Creek, a tributary to the Little Sequatchie River (Fig. 8). This cave is approximately 200 meters in length; spiders were collected ~ 50 meters from the cave entrance on the cave ceiling and walls, in total darkness.

Etymology.

The specific name is a matronym in honor of N. K. Jemisin whose 'Broken Earth’ book series features a subterranean colony, including scientists who study caves.

Remarks.

Nesticus jemisinae sp. nov. is a relictual, single-site endemic whose morphology is quite distinct from that of other members of the species group. This species is nested within a diverged nuclear and mitochondrial subclade of the Nesticus archeri group, sister to N. pecki and N. archeri (Figs 3, 4, 6).