Aphonopelma superstitionense Hamilton, Hendrixson & Bond

Hamilton, Chris A., Hendrixson, Brent E. & Bond, Jason E., 2016, Taxonomic revision of the tarantula genus Aphonopelma Pocock, 1901 (Araneae, Mygalomorphae, Theraphosidae) within the United States, ZooKeys 560, pp. 1-340 : 242-244

Taxon classification Animalia Araneae Theraphosidae

Aphonopelma superstitionense Hamilton, Hendrixson & Bond sp. n. Figures 138, 139, 140, 141

Types.

Male holotype (APH_1443) collected from the Superstition Mtns, Flat Iron, just above Flat Bowl Siphon Draw, 33.440386 -111.457602 1, elev. 3450ft., 1.xii.2011, coll. Tim Cota; deposited in AUMNH. Paratype female (APH_0504) from 0.25 miles S Crimson Rd on Usery Pass Rd., 33.479188 -111.625608 1, elev. 2009ft., 19.v.2009, coll. Brent E. Hendrixson, Bernadette DeRussy, Sloan Click; deposited in AUMNH. Paratype male (APH_1607) from the Superstition Mtns, Peralta Canyon Trail, 33.408937 -111.354086 1, elev. 2982ft., 11.xi.2012, coll. Brent E. Hendrixson, Tim Cota, Molly Taylor; deposited in AMNH.

Etymology.

The specific epithet is a neuter adjective taken from type locality, the Superstition Mountains, where this species was first discovered.

Diagnosis.

Aphonopelma superstitionense (Fig. 138) is a member of the paloma species group and can be distinguished by a combination of morphological, molecular, and geographic characteristics. Nuclear DNA identifies Aphonopelma superstitionense as a strongly supported, phylogenetically-distinct lineage (Fig. 8) that is a sister lineage to Aphonopelma mareki sp. n., Aphonopelma parvum sp. n., and Aphonopelma saguaro sp. n. Aphonopelma superstitionense can easily be differentiated from syntopic populations of Aphonopelma chalcodes by its much smaller size, and can be differentiated from other members of the paloma species group by locality. Importantly, Aphonopelma superstitionense males possess a slightly swollen femur III, which is different from the normal condition of the femur in Aphonopelma parvum ). The most significant measurements that distinguish male Aphonopelma superstitionense from its closely related phylogenetic and syntopic species are Cl and the extent of scopulation on metatarsus IV. Male Aphonopelma superstitionense can be distinguished by possessing a smaller Cl/M3 (≤1.12; 1.05-1.12) than Aphonopelma mareki (≥1.18; 1.18-1.50), Aphonopelma paloma (≥1.17; 1.17-1.32), Aphonopelma parvum (≥1.20; 1.20-1.39), and Aphonopelma saguaro (≥1.17; 1.17-1.25); and a smaller L4 scopulation extent (14%-20%) than Aphonopelma chalcodes (42%-76%) and Aphonopelma parvum (36%-44%). The most significant measurements that distinguish female Aphonopelma superstitionense from its closely related phylogenetic and syntopic species are T1 and the extent of scopulation on metatarsus IV. Female Aphonopelma superstitionense can be distinguished by possessing a smaller T1/M4 (0.84 ± (only 1 specimen)) than Aphonopelma paloma (≥0.93; 0.93-1.10), Aphonopelma parvum (≥0.91; 0.91-1.00), and Aphonopelma saguaro (1.02 ± (only 1 specimen)); and a smaller L4 scopulation extent (26% ± (only 1 specimen)) than Aphonopelma chalcodes (56%-81%) and Aphonopelma parvum (33%-42%). There are no significant measurements that separate female Aphonopelma superstitionense and Aphonopelma mareki .

Description of male holotype

(APH_1443; Fig. 139). Specimen preparation and condition: Specimen collected wandering and preserved in 80% ethanol; original coloration faded due to preservation. Left legs I, III, IV, and left pedipalp removed for measurements and photographs; stored in vial with specimen. Right legs II-IV removed for DNA and stored at -80°C in the AUMNH (Auburn, AL). General coloration: Faded black/brown. Cephalothorax: Carapace 5.594 mm long, 5.171 mm wide; densely clothed with faded pubescence, appressed to surface; fringe covered in longer setae not closely appressed to surface; foveal groove medium deep and straight; pars cephalica region rises very gradually from foveal groove on a straight plane towards the ocular area; AER slightly procurved, PER very slightly recurved - mostly straight; normal sized chelicerae; clypeus extends forward on a slight curve; LBl 0.824, LBw 1.028; sternum hirsute, clothed with faded, densely packed, short setae. Abdomen: Densely clothed in short black/brown pubescence with numerous longer, lighter setae interspersed (generally red or orange in situ); dense dorsal patch of black Type I urticating bristles ( Cooke et al. 1972) - smaller and distinct from large species. Legs: Hirsute; densely clothed in faded pubescence. Metatarsus I slightly curved. F1 6.804; F1w 1.308; P1 2.234; T1 6.002; M1 4.755; A1 3.455; F3 5.475; F3w 1.698; P3 1.878; T3 4.567; M3 5.127; A3 3.571; F4 6.418; F4w 1.335; P4 2.061; T4 5.902; M4 6.571; A4 3.871; femur III is swollen. All tarsi fully scopulate. Extent of metatarsal scopulation: leg III (SC3) = 47.7%; leg IV (SC4) = 20.4%. Three ventral spinose setae and one prolateral spinose seta on metatarsus III; nine ventral spinose setae and one prolateral spinose seta on metatarsus IV (though two are clustered near the row of spinose setae that line the margin with the tarsus); two prolateral spinose setae and two ventral spinose setae on tibia I; one ventral spinose seta on patella I; one megaspine present on the retrolateral tibia, at the apex of the mating clasper; two megaspines on the apex on the retrolateral branch of the tibial apophyses; one megaspine at the base of the prolateral branch of the tibial apophyses. Coxa I: Prolateral surface covered by fine, hair-like setae. Pedipalps: Hirsute; densely clothed in the same setal color as the other legs, with numerous longer ventral setae; one spinose seta at the apical, prolateral femur; two spinose setae on the prolateral patella; four prolateral spinose setae and one ventral on the palpal tibia; PTl 3.787, PTw 1.236. Palpal bulb is very short and stout. When extended, embolus tapers with a curve to the retrolateral side; embolus slender, no keels; distinct dorsal and ventral transition from bulb to embolus.

Variation (3).Cl 5.594-6.586 (5.961 ± 0.31), Cw 5.171-6.302 (5.592 ± 0.36), LBl 0.824-0.93 (0.869 ± 0.03), LBw 1.006-1.044 (1.026 ± 0.01), F1 6.624-7.28 (6.903 ± 0.2), F1w 1.308-1.469 (1.37 ± 0.05), P1 2.234-2.382 (2.32 ± 0.04), T1 5.731-6.501 (6.078 ± 0.23), M1 4.719-4.839 (4.771 ± 0.04), A1 3.387-3.764 (3.535 ± 0.12), L1 length 22.843-24.729 (23.607 ± 0.57), F3 5.475-6.065 (5.708 ± 0.18), F3w 1.592-1.923 (1.738 ± 0.1), P3 1.878-2.021 (1.957 ± 0.04), T3 4.545-4.916 (4.676 ± 0.12), M3 5.127-5.883 (5.473 ± 0.22), A3 3.398-3.622 (3.53 ± 0.07), L3 length 20.618-22.234 (21.345 ± 0.47), F4 6.418-6.966 (6.753 ± 0.17), F4w 1.294-1.538 (1.389 ± 0.08), P4 2.061-2.265 (2.149 ± 0.06), T4 5.902-6.666 (6.193 ± 0.24), M4 6.571-7.264 (6.983 ± 0.21), A4 3.871-3.929 (3.902 ± 0.02), L4 length 24.823-27.09 (25.98 ± 0.65), PTl 3.786-3.951 (3.841 ± 0.05), PTw 1.236-1.394 (1.308 ± 0.05), SC3 ratio 0.404-0.477 (0.429 ± 0.02), SC4 ratio 0.147-0.204 (0.185 ± 0.02), Coxa I setae = very thin tapered, F3 condition = slightly swollen/swollen.

Description of female paratype

(APH_0504; Fig. 140). Specimen preparation and condition: Specimen collected live from burrow, preserved in 80% ethanol; original coloration faded due to preservation. Left legs I-IV, and pedipalp removed for photographs and measurements; stored in vial with specimen. Right legs III & IV removed for DNA and stored at -80°C in the AUMNH (Auburn, AL). Genital plate with spermathecae removed and cleared, stored in vial with specimen. General coloration: Faded black/brown. Cephalothorax: Carapace 6.972 mm long, 6.823 mm wide; Very hirsute, densely clothed with short faded black/brown pubescence closely appressed to surface; fringe densely covered in slightly longer setae; foveal groove medium deep and slightly recurved; pars cephalica region gently rises from thoracic furrow, arching anteriorly toward ocular area; AER procurved, PER mostly straight; chelicerae robust, clypeus extends on a curve; LBl 1.139, LBw 1.384; sternum hirsute, clothed with short faded setae. Abdomen: Densely clothed dorsally in short faded black setae with longer, lighter setae (generally red or orange in situ) focused near the urticating patch; dense dorsal patch of black Type I urticating bristles ( Cooke et al. 1972) - smaller and distinct from large species. Spermathecae: Paired and separate, with capitate bulbs, short, widening towards the bases; not fused. Legs: Hirsute; densely clothed in short faded black/brown pubescence; F1 6.151; F1w 1.943; P1 2.792; T1 4.708; M1 3.561; A1 3.15; L1 length 20.362; F3 4.789; F3w 1.741; P3 2.13; T3 3.566; M3 3.458; A3 3.065; L3 length 17.008; F4 6.308; F4w 1.826; P4 2.677; T4 4.939; M4 5.544; A4 3.807; L4 length 23.275. All tarsi fully scopulate. Extent of metatarsal scopulation: leg III (SC3) = 64.2%; leg IV (SC4) = 26.3%. Three ventral spinose setae and one prolateral spinose seta on metatarsus III; nine ventral spinose setae on metatarsus IV (though two are clustered near the row of spinose setae that line the margin with the tarsus). Coxa I: Prolateral surface covered by tapered, thin tapered, and fine, hair-like setae. Pedipalps: Densely clothed in the same setal color as the other legs; one spinose seta on the apical, prolateral femur; five prolateral spinose setae (two at the apical, prolateral border with the tarsus) and two ventral spinose setae on the tibia (one at the apical, prolateral border with the tarsus).

Material examined.

United States: Arizona: Maricopa: 0.25 miles S Crimson Rd on Usery Pass Rd, 33.479188 -111.625608 1, 2009ft., [APH_0504, 19/5/2009, 1♀, Brent E. Hendrixson, Bernadette DeRussy, Sloan Click, AUMNH]; Apache Trail, 33.540608 -111.345427 2, 2651ft., [APH_1643, 29/11/2012, 1♂, Tim Cota, AUMNH]; Pinal: Superstition Mtns, Flat Iron, just above Flat Bowl Siphon Draw, 33.440386 -111.457602 1, 3450ft., [APH_1443, 1/12/2011, 1♂, Tim Cota, AUMNH]; Superstition Mtns, Peralta Canyon Trail, 33.408937 -111.354086 1, 2982ft., [APH_1607, 11/11/2012, 1♂, Brent E. Hendrixson, Tim Cota, Molly Taylor, AMNH].

Distribution and natural history.

Aphonopelma superstitionense can be found inhabiting the Arizona/New Mexico Mountains and Sonoran Basin and Range Level III Ecoregions of central Arizona east of the Phoenix Metropolitan Area (Fig. 141), specifically in and around the foothills of the Superstition Mountains and may be present in or near the Pinal Mountains. Aphonopelma superstitionense can be found in syntopy with Aphonopelma chalcodes and perhaps Aphonopelma marxi at higher elevation. The breeding season, when mature males abandon their burrows in search of females, occurs during the late fall and early winter ( November–December).

Conservation status.

Aphonopelma superstitionense appears to have a limited distribution restricted to the foothills and area in or around the Superstition Mountains. These diminutive tarantulas are probably common but can be incredibly difficult to find due to the cryptic nature of their burrows and narrow window of activity during the year. The Phoenix Metropolitan area is experiencing rapid growth and recreational activities in the Superstition Mountains threaten suitable habitat for this species. The status of Aphonopelma superstitionense seems secure (e.g., it is probably common in remote sections of the Superstition Wilderness Area) but should be monitored.

Remarks.

Other important ratios that distinguish males: Aphonopelma superstitionense possess a smaller PTl/M3 (≤0.74; 0.67-0.74) than Aphonopelma mareki (≥0.76; 0.76-0.92), Aphonopelma paloma (≥0.77; 0.77-0.85), Aphonopelma parvum (≥0.81; 0.81-0.88), and Aphonopelma saguaro (≥0.78; 0.78-0.84); a smaller L3 scopulation extent (40%-48%) than Aphonopelma chalcodes (65%-86%), Aphonopelma mareki (50%-56%), and Aphonopelma parvum (60%-65). Other important ratios that distinguish females: Aphonopelma superstitionense possess a smaller M3/M4 (0.62 ± (only 1 specimen)) than Aphonopelma mareki (≥0.66; 0.66-0.77), Aphonopelma parvum (≥0.67; 0.67-0.74), and Aphonopelma saguaro (0.70 ± (only 1 specimen)); a smaller Cl/M4 (1.25 ± (only 1 specimen)) than Aphonopelma paloma (≥1.44; 1.44-1.60); a larger L1/L3 (1.19 ± (only 1 specimen)) than Aphonopelma parvum (≥1.09; 1.09-1.14); a larger F1/T1 (1.30 ± (only 1 specimen)) than Aphonopelma saguaro (1.13 ± (only 1 specimen)). Certain morphometrics have potential to be useful, though due to the amounts of variation, small number of specimens, and the small differences between species, no other are claimed to be significant at this time (see Suppl. material 2). During evaluation of traditional two-dimensional PCA morphospace and three-dimensional PCA morphospace (PC1~PC2~PC3), males of Aphonopelma superstitionense separate from Aphonopelma chalcodes and Aphonopelma parvum , but do not separate from Aphonopelma mareki , Aphonopelma paloma , or Aphonopelma saguaro . Female Aphonopelma superstitionense separate from Aphonopelma chalcodes , but do not separate from Aphonopelma mareki , Aphonopelma paloma , Aphonopelma parvum , or Aphonopelma saguaro in two-dimensional morphological space, yet when three-dimensional morphospace is plotted, Aphonopelma superstitionense appears to separate from Aphonopelma parvum (though we only have 1 female Aphonopelma superstitionense to compare). PC1, PC2, and PC3 explain ≥99% of the variation in all analyses. Mitochondrial DNA (CO1) identifies Aphonopelma superstitionense as a polyphyletic group with some members grouping with the Aphonopelma mareki lineage (Fig. 7). Both species were previously identified as putative novel species ( Hamilton et al. 2014). Nuclear DNA identifies what we feel is a more accurate evolutionary history of the Aphonopelma superstitionense lineage and highlights how CO1 is not effective at accurately delimiting species boundaries within this group possibly due to mitochondrial introgression.