Hexurella zas, Monjaraz-Ruedas & Mendez & Hedin, 2023

Monjaraz-Ruedas, Rodrigo, Mendez, Raymond Wyatt & Hedin, Marshal, 2023, Species delimitation, biogeography, and natural history of dwarf funnel web spiders (Mygalomorphae, Hexurellidae, Hexurella) from the United States / Mexico borderlands, ZooKeys 1167, pp. 109-157 : 109

Hexurella zas sp. nov.

Fig. 9

Hexurella pinea Hedin et al 2019: figs 3, 4, (in part).

Material examined.

Type material: Holotype: - Maricopa Co. • ♂ holotype; Mt. Ord , 0.5 mi NW Mt. Ord summit, FDR-1688, 33.9125, -111.4145; 15 Apr. 2022; R.W. Mendez leg.; RWM 22_102; SDSU_TAC000693 ; Paratype: • ♀ paratype; data as for holotype; SDSU_TAC000694 .

Non-type material.

USA - Arizona, Maricopa Co. • 6♀, 5 imm; Mt. Ord, 0.5 mi NW Mt. Ord summit, FDR-1688, 33.9119, -111.4146; 11 Dec. 2021; R.W. Mendez, M.A. Leimroth leg.; RWM 21_082. - Maricopa Co. • 9♂; Mt. Ord, 0.5 mi NW Mt. Ord summit, FDR-1688, 33.9125, -111.4145; 15 Apr. 2022; R.W. Mendez leg.; RWM 22_102. - Yavapai Co. • 5♂, 3♀, 2 imm; Bradshaw Mtns, 2.15 mi S The Cements, off W Wagoner Road, 34.1374, -112.4475; 14 Apr. 2022; R.W. Mendez leg.; RWM 22_100. - Yavapai Co. • 1♀, 1 imm; Bradshaw Mtns, Crown King Road, near Perkins Tunnel Spring, 34.2263, -112.3092; 24 Mar. 2012; M. Hedin, A. Schönhofer, C. Richart, A. DiDomenico, E. Stiner, K. Emata, E. Garcia, D. Sitzmann leg.; MCH 12_009.

Diagnosis.

Differs from H. pinea in the condition of prolateral male femur I, with H. zas sp. nov. possessing 11 or more long spines, totaling a larger number than found in H. pinea males (single exception noted above).

Description of ♂ holotype

(SDSU_TAC000693; Fig. 9A-E ). Total length (including chelicerae) 2.6, cephalothorax and appendages pale yellow cream (in alcohol), eye tubercle with dark pigmentation beneath. Fangs yellow cream like cephalothorax, with longer basal to medial hairs projecting inwards. Abdomen about concolorous with cephalothorax, evenly covered with fine hairs. Tergal plates barely lighter than abdomen, anterior rectangular plate covering most of abdominal width, posterior oval plate (hard to discern) covering ~ 2/3 abdominal width, both plates covered with fine hairs. Carapace (including chelicerae) 1.125 long, 0.825 wide, suboval in shape as viewed dorsally, gently rounded in front, slightly indented behind. Low and convex viewed laterally, essentially lacking hairs, a few fine hairs towards lateral posterior margins, without evident cephalic grooves, dorsal pigmentation (in alcohol) mostly lacking. Thoracic groove very shallow, linear, barely pigmented, 0.05. Eyes set on low tubercle, ~ 1/3 width of anterior carapace, offset from anterior carapace edge by distance equal to depth of tubercle itself. Anterior lateral eyes 2-3 × larger than all others, themselves ca. equal in size. Anterior eye row very slightly procurved, posterior eye row approximately straight. Sternum 0.6 long, 0.5 wide, sparsely covered with hairs concentrated on lateral edges, sternal sigilla not obvious. Labium 0.1 long, 0.2 wide, with forwards-projecting hairs. Endites 0.25 long, 0.2 wide, whitish and thickened medially, forward projecting hairbrushes on prolateral edge. Chelicerae 0.4 long, 0.1 wide at base (viewed from above), promargin with four large teeth, microteeth between; retromargin with one basal microtooth. Leg formula 4132. All legs clothed with fine hairs; legs III and IV with more numerous spines on all surfaces, and with conspicuous spines distally. Leg I thickened, with femur 1/3 as deep as long, prolateral surface of femur with medial patch of 11 spines appearing as two diagonal rows (5 in basal row, 6 in distal row; Fig. 9A ), tibia and metatarsus with three and one ventral spines, respectively. Leg I (prolateral view) total length 2.2 (0.75, 0.4, 0.5, 0.4, 0.3). Palp (prolateral view) total length 1.4 (0.5, 0.2, 0.4, 0.3). Palp clothed with fine pale hairs and weak spines; tibia thick, cylindrical, two times as long as deep; weak comb of 3-4 thicker retromarginal hairs on distal edge. Abdomen 1.5 long, 0.9 wide, suboval, somewhat flattened. Posterior median spinnerets slightly shorter than anterior laterals, posterior lateral spinnerets tapering, four-segmented. Embolus closely appressed to the conductor (viewed at 10X magnification).

Description of ♀ paratype

(SDSU_TAC000694; Fig. 9F ). Total length (including chelicerae) 3.10, cephalothorax and appendages pale cream (in alcohol), including legs. Eye tubercle with dark pigmentation beneath. Fangs pale cream, clothed with long, basal hairs projecting inwards. Abdomen very slightly darker than cephalothorax, densely covered with fine hairs, heart mark apparent. Tergal plates ca. same color but shinier than abdomen, anterior oval plate covering most of abdominal width, posterior oval plate covering ~ 1/3 of abdominal width, both plates covered with fine hairs. Carapace (including chelicerae) 1.27 long, 0.87 wide, suboval in shape as viewed dorsally, gently rounded in front, slightly invaginated behind. Low and convex viewed laterally, essentially lacking hairs, a few fine hairs towards lateral posterior margins, without evident cephalic grooves, dorsal pigmentation (in alcohol) mostly lacking. Thoracic groove shallow, linear, slightly pigmented, 0.125. Eyes set on low tubercle, ~ 1/3 width of anterior carapace, offset from anterior carapace edge by distance equal to depth of tubercle itself. Anterior lateral eyes ~ 3 × larger than all others, themselves ca. in size. Anterior eye row very procurved, posterior eye row approximately straight. Sternum 0.7 long, 0.6 wide, sparsely covered with long hairs, sternal sigilla not obvious. Labium 0.1 long, 0.2 wide, gently rounded along whitish anterior edge, with forwards-projecting hairs. Endites 0.375 long, 0.3 wide, whitish and thickened medially, conspicuous forward projecting hairbrushes on prolateral edge. Chelicerae 0.5 long, 0.2 wide at base (viewed from above), promargin with three large teeth, microteeth between; retromargin with one basal microtooth. Leg formula 4132. All legs clothed with fine hairs; legs I and II mostly without dorsal or lateral spines but with ventral spines on tibia and metatarsus; legs III and IV with more numerous spines on all surfaces, and with conspicuous spines distally. Paired tarsal claws with 5-7 microteeth. Leg I (prolateral view) total length 2.2 (0.75, 0.4, 0.4, 0.4, 0.3). Palp (prolateral view) total length 1.5 (0.5, 0.3, 0.4, 0.3), clothed with long hairs, three spines on ventral tibia. Abdomen 1.8 long, 1.2 wide, suboval, somewhat flattened. Posterior median spinnerets slightly shorter than anterior laterals, posterior lateral spinnerets tapering, four-segmented, third segment slightly longer than others and pseudo-segmented. Spermathecae damaged during dissection.

Variation.

Important male variation exists in both populations considered. A randomly chosen subset of three non-type males from the type locality (Mt. Ord) reveals a variable number of prolateral femoral spines (11-13), although not arranged in distinct diagonal rows as in the holotype specimen. These males also reveal variation in leg I metatarsus ventral spination, with up to 3 or 4 total spines. Consideration of a randomly chosen subset of four males from the Bradshaw Mtns (RWM 22_100) also reveals a variable number of prolateral femur I spines (from 11-16 long spines, Fig. 9C, D ), again not obviously arranged in distinct rows, and with a variable number (3-4) of ventral spines on metatarsus I.

Distribution and natural history.

Known from three locations in low to mid-elevation (1325-1850m) habitats in the Arizona transition zone north of Phoenix. Collections in the Bradshaw Mountains are from sclerophyllous oak litter like that preferred by H. apachea , while Mt. Ord specimens were taken from nearly pure Rhamnus ilicifolia Kellogg (Hollyleaf Redberry). The lower elevation collections in the Bradshaws have been in sheltered canyons and rock outcrops, where they are protected from the sun though remain mostly dry, while the higher elevation Mt. Ord locale was on an open, north-facing slope.

Like H. apachea , webs consist of a convoluted structure of reticulate tunnels and void-filling sheets. Seemingly less reliant on organic substrates, however they have been collected in crumbly soils and gravel mixtures a short distance away from the main patches of litter. Mature males have been collected in April and May. Dedicated searching at Mt. Ord in mid-December 2021 produced numerous females and immatures, but no males. Pockets of snow were present on the ground, but spiders were still active in their webs. When revisiting the Mt. Ord location the following spring, densities in H. zas were similar to H. apachea , with multiple individuals sharing small rocks and eleven males seen (two escaping) in an area of approximately 3 m2.

Etymology.

A noun in apposition which means “snow” in the Western Apache language (Bray, 1998), referencing the colder temperatures and increased snowfall faced by this species in winter. The Western Apache, along with the Yavapai, are the original occupants of the land H. zas sp. nov. is found on and their language is undergoing important revitalization efforts.

Discussion.

DELINEATE and SPEEDEMON ε = 0.0185 analyses (Table 2 ) recover Bradshaws (South) as a separate species from Mt. Ord (FarSouth). We here conservatively treat these as conspecific, based on overall shared male leg I morphology (Fig. 9 ), the fact that this morphology varies within sample locations, and that patterns of character variation among these disjunct locations overlap. We recognize that these populations are geographically disjunct with mostly unsuitable intervening habitats (Fig. 3 ); further sampling in the gap that separates these populations will be important in future research.

Conservation status.

Likely secure in appropriate habitats.

Figures

Figure 3. Map of all collection localities. Phylogeographic lineage names for H. apachea as in text. The unsampled type locality of H. pinea is designated with a special symbol; all other type (or near type) localities were sampled, see text.

Figure 9. H. zas sp. nov. A ♂ holotype leg I, prolateral view (SDSU _ TAC 000693, Mt Ord) B ♂ holotype palp, retrolateral view (SDSU _ TAC 000693, Mt Ord) C ♂ leg I, prolateral view (SDSU _ TAC 000692, Bradshaw Mtns) D ♂ palp, retrolateral view (SDSU _ TAC 000692, Bradshaw Mtns) E live ♂, Mt. Ord (RWM 22 _ 102) F ♀ paratype (SDSU _ TAC 000694, Mt Ord).