Aptostichus stanfordianus Smith, 1908

Bond, Jason E., 2012, Phylogenetic treatment and taxonomic revision of the trapdoor spider genus Aptostichus Simon (Araneae, Mygalomorphae, Euctenizidae), ZooKeys 252, pp. 1-209 : 49-55

Aptostichus stanfordianus Smith, 1908 Figures 106-114Map 10, 11

Aptostichus stanfordianus Smith, 1908: 221. Female holotype, specimen no. 102 deposited in the Entomological Museum of Stanford University, presumed lost.

Type material.

Specimens described by Smith (1908) and deposited in the "Entomological Museum of Stanford University" have long been considered to be lost (e.g., Coyle 1974). To clarify the taxonomic status of the species, I designate herein a neotype because the name-bearing type specimen is believed to no longer exist. Female neotype(MY3248; EU570032, EU569895) designated from California, San Mateo Co., Hwy 92, 1.5km E of HWY 1, 37.48452, -122.39926 1, elev. 76m, coll. A. Stockman 2.vi.05, deposited in AUMNH. Based on the evidence, Smith’s (1908) drawings and documentation of locality data for the species, I am reasonably confident that designation of this specimen as the neotype is consistent with what is known of the former name-bearing type. The locality from which the neotype was collected is ~20km to the west of Smith’s type locality, described as "Stanford Estate" near Stanford University; considerable development has occurred in this region over the last century and specimens from the direct vicinity of Stanford University are not available. Smith noted collecting specimens, for the series on which Aptostichus stanfordianus was described, from points to the west below ~121m in elevation. The carapace length and width for the neotype are noted in the variation section below (enclosed in brackets []) and a complete set of measurements are archived in the Dryad Data Repository at doi: 10.5061/dryad.3b95n; specimen coloration is similar to that illustrated in figure 110. As noted above, GenBank accession numbers EU570032 (12S-tRNA-val-16S) and EU569895 (18S (partial)-ITS1-5.8S-ITS2) are attributed to this specimen.

Diagnosis.

Individuals of this species are particularly difficult to distinguish morphologically (Figs 106-112) from Aptostichus angelinajolieae specimens but were diagnosed on the basis of a unique set of mtDNA nucleotide substitutions documented in Bond and Stockman (2008; but see discussion below). The species is separated geographically from Aptostichus angelinajolieae by the Salinas River Valley and is found only in inland habitats whereas Aptostichus miwok is found in coastal dunes. Aptostichus miwok is much lighter in color than Aptostichus stanfordianus (Figs 106, 110, 113, 114).

Description.

Female described by Smith (1908).

Material examined.

United States: California: Alameda Co.: Alameda, 37.7652, -122.2416 6, 4m, E Kools 1.i.94 [AP1277, 1♀, CAS]; Berkeley, 37.8776, -122.266 6, 87m, 21.x.53 [AP251, 1♀, CAS]; J Doyen 10.x.72 [AP296, 1♀, AMNH]; Del Valle Regional Park, 37.5889, -121.6959 5, 249m, M Thompson, 1.xi.81 [AP609, 1♀, CAS]; Lake del Valle St Recreational Area, Campsite #53, 37.5722, -121.69 1, 218m, A Stockman 12.v.05 [MY3091, 1juv, AUMNH]; Colusa Co.: Bear Valley Rd, 3.2km NW intersection hwy 20, 39.0204, -122.3897 1, 396m, J Bond, M Hedin 12.i.02 [MY282-84, 3juv, AUMNH]; Contra Costa Co.: 0.8km E of S Gate of Mount Diablo State Park, 37.853, -121.9291 5, 532m, P Hird 7.ii.47 [AP171, 1♂, AMNH]; Orinda Village, San Pablo Ridge below Eureka Peak, 37.8801, -122.2102 5, 335m, E Schlinger 13.xi.70 [AP162, 1♂, CAS]; Tilden Park, 37.9024, -122.2471 3, 325m, J Fraser 24.x.80 [AP501, 1♂, AMNH]; Briones Rd, near Bear Creek Rd, 37.9693, -122.1571 1, 134m, A Stockman 15.vi.05 [MY3371, 1♀, AUMNH]; Morgan Territory Rd, 3.5km S Marsh Creek Rd, 37.8794, -121.8653 1, 235m, A Stockman 12.v.05 [MY3085, 3086, 2♀, AUMNH]; Briones Regional Park, Alhambra Creek Staging Creek, 37.9537, -122.1250 1, 120m, M Hedin, J Starrett, D Carlson, R Keith, H Wood, J Ledford 31.iii.2010 [MY3815, 1♀, AUMNH]; Fresno Co.: Hwy 198, 35.2km E HWY 25, 36.0962, -120.5249 1, 464m, A Stockman 9.vi.05 [MY3305, 1♀, AUMNH]; Marin Co.: Kentfield, 37.9533, -122.5578 6, 69m, B Hopey 19.vi.36 [AP271, 1♀, AMNH]; Ridge between San Anselmo & San Rafael, 37.994, -122.558 5, 180m, L Freihofer 13.xi.76 [AP160, 1♂, CAS]; Tamalpais St Park, 37.9231, -122.5958 5, 750m, M Bentzien 18.xi.68 [AP1275, 1♀, SCW]; N San Pedro Rd at Pt San Pedro Rd, 37.9974, -122.4571 1, 20m, A Stockman 15.vi.05 [MY3357, 1juv, AUMNH; MY3358, 1♀, CAS]; Merced Co.: Dinosaur Pt Rd, 0.8km SE HWY 152, 37.0649, -121.2102 1, 412m, A Stockman 7.vi.05 [MY3284, 1juv, AUMNH]; Dinosaur Pt Rd, 2.7km SE of Hwy 152, 37.067, -121.1941 1 305m, A Stockman 7.vi.05 [MY3279, 1juv, AUMNH]; Monterey Co.: Hwy 198, 10.9km E Hwy 25, 36.1988, -120.7381 1, 696m, A Stockman 9.vi.05 [MY3308, 1♀, 12juv, AUMNH]; Maher Rd, ~2.4km S San Miguel Canyon Rd, 36.8333, -121.6761 1, 52m, A Stockman 11.vi.05 [MY3325-27, 3♀, AUMNH]; San Juan Canyon S Salinas, 36.8307, -121.5377 1, 102m, J Bond 8.xii.05 [MY3464, 3465, 2♀, AUMNH]; Napa Co.: Chiles Pope Valley Rd, just S Pope Valley, 38.5963, -122.3997 1, 250m, M Hedin, J Ledford 31.i.08 [MY3639, 1juv, AUMNH]; Hwy 121, 1.9km S jct w/Hwy 128 at Moskowite Corners, along Capel Creek, 38.432, -122.2073 1, 250m, M Hedin, J Ledford 31.i.08 [MY3640, 1♂, AUMNH]; N side Howell Mountain, 38.5998, -122.4392 5, 235m, H Leech 3.xi.83 [AP414, 1♂, CAS]; Hwy 128, 3.2km W Monticello Dam, 38.4952, -122.1236 1, 143m, A Stockman 13.vi.05 [MY3342, 1♀, AUMNH]; San Benito Co.: ~2.25km from Pinnacles Natl Monument entrance, 36.4872, -121.2233 1, 502m, J Bond 7.v.97 [AP779-81, 2♀, 1juv, AUMNH]; ~2km before Pinnacles Natl Monument entrance, 36.4544, -121.2219 1, 470m, J Bond 3.iv.96 [AP717, 738, 1♀, 1juv, AUMNH; AP734, 1♀, CAS]; ~6km from Pinnacles Natl Monument entrance Hwy 146, 36.4323, -121.2275 1, 4m, J Bond, W Bond 27.vii.08 [MY3740, 1♀, AUMNH]; Pinnacles Natl Monument, 36.4872, -121.2066 1, 475m, J Bond 3.iv.96 [AP731, 1juv, AUMNH]; Pinnacles Natl Monument, ~2.25km from entrance, 36.4873, -121.2233 1, 475m, J Bond 3.iv.96 [AP747, 1♀, AUMNH]; Pinnacles Natl Monument, W Chaparral ranger station, 36.4893, -121.2119 1, 439.9m, J Starrett 1.vii.03 [MY2272, 1♀, AUMNH]; San Juan Canyon Rd/G1, 17km S Hwy 156, near Fremont Peak SP entrance, 36.7602, -121.502 4, 850m, A Stockman 7.vi.05 [MY3291, 1♀, AUMNH]; San Juan Canyon Rd vic. Fremont Peak St Park, 36.7858, -121.4607 1, 549m, M Hedin, P Paquin, J Starrett 5.iv.03 [MY731, 1♀, AUMNH]; Hwy 25, N Hwy 146, ~2.4km N Gloria Rd, 36.5796, -121.1906 1, 398m, A Stockman 8.v.05 [MY3301, 1♀, AUMNH]; San Juan Canyon Rd/G1, 3.2km S Hwy 156, 36.8166, -121.5264 1, 130m, A Stockman 8.vi.05 [MY3295-97, 2♀ 1 juv., AUMNH]; San Juan Canyon Rd/G1, 12.2km S Hwy 156, 36.7852, -121.4632 1, 566m, A Stockman 8.vi.05 [MY3292, 3294 2juv, AUMNH; MY3293, 1♀, AMNH]; vic Hollister Hills, S of Hollister, 36.7716, -121.4112 1, 220m, M Hedin, J Starrett, D Leavitt, D Carlson, B Keith 27.iii.2011 [MY3795, 4012, 2♀, AUMNH]; New Idria Rd, Griswold Hills, Griswold Canyon, 36.5417, -120.8342 1, 420 m, M Hedin, J Starrett, D Leavitt, D Carlson, B Keith 28.iii.2011 [MY4010, 1♀, AUMNH]; New Idria Rd, 0.8km N New Idria mine site, 36.4235, -120.6674 1, 725m, M Hedin, J Starrett, D Leavitt, D Carlson, B Keith 29.iii.2011 [MY4003, 1♀, AUMNH]; Panoche Rd, E Panoche Pass, W Llanada, 36.6190, -120.9771 1, 40m, M Hedin, J Starrett, D Leavitt, D Carlson, B Keith 28.iii.2011 [MY3791, 4008, 4011, 2♀, 1juv, AUMNH]; San Francisco Co.: San Francisco, 37.75, -122.45 7, 230m, R Schick 1.ix.61 [AP166, 1♂, AMNH]; 23.i.34 [AP473, 1♀, AMNH]; San Joaquin: 6mi W Tracy, 37.7426, -121.5566 5, 80m, J McSwain 30.iii.49 [AP154, 1♂, AMNH]; San Mateo Co.: ~1.6km W Woodside city limit, 37.4416, -122.2416 1, 88m, J Bond 3.v.97 [AP765-68, 1♀, 3juv, AUMNH]; Alpine Rd, 4km E Pescadero Rd, 37.291, -122.2294 1, 314m, A Stockman 13.v.05 [MY3107-09, 3♀, AUMNH]; Half Moon Bay, 37.4611, -122.440 5, 17m, W Lange 21.ii.40 [AP444, 1♀, AMNH]; Highway 84 on way to La Honda, 37.3988, -122.2594 1, 257m, J Bond 4.v.97 [AP770-71, 2juv, AUMNH]; Hillsborough, swimming pool along Summit Dr, 37.5728, -122.3854 5, 146m, B Thompson 25.ix.72 [AP159, 1♂, CAS]; Hwy 92, 1.5km E HWY 1, 37.4845, -122.3992 1, 76m, A Stockman 2.vi.05 [MY3247-49, 3♀, AUMNH]; San Mateo, 37.5568, -122.3177 7, 60m, 31.xii.38 [AP474, 1♀, AMNH]; Santa Clara Co.: 14.5km W Morgan Hill, 1.6km Loma Prieta mountain peak, along Casa Loma Rd, Llagas Creek ravine, 37.1427, -121.7812 4, 250m, W Icenogle 10.x.70 [AP273, 1♀, 164juv, CAS]; Alum Rock St Park, 37.397, -121.797 3, 200m, W Icenogle 11.x.70 [AP187, 1♀, 59juv. AMNH]; 8.x.78 [AP261, 1♀, CAS]; 11.xi.70 [AP264, 1♀, 14juv, AMNH]; 8.x.70 [AP478, 1♀, 32juv, CAS]; 30.vii.71 [AP488, 1♂, AMNH]; Bear Creek Rd, ~0.4km W jct w/ hwy 17, 37.1887, -121.9954 1, 213m, M Hedin, P Paquin, J Starrett 5.iv.03 [MY725, 1♀, AUMNH]; Guadalupe Creek, 37.1777, -121.87479 3, 228m, D Ubick 17.ii.76 [AP448, 1juv, CAS]; Marsh Rd, ~0.8km S Calaveras Reservoir, ~6.4km E Milpitas, 37.4501, -121.8138 5, 240m, W Icenogle 7.x.70 [AP199, 1♀, 1juv, CAS; AP254, 1♀, 52juv, AUMNH]; Marsh Rd, 0.8km S Calaveras Reservoir, 1.6km NE intersection Marsh & Felter Rds, 37.4468, -121.8099 4, 274m, W Icenogle 7.x.70 [AP466, 1♀, 87juv, AUMNH]; Congress Springs Rd/Hwy 9, 37.2609, -122.0985 1, 492m, A Stockman 13.v.05 [MY3095-99, 3♀, 2juv, AUMNH]; East Dunne Rd, 37.1519, -121.5865 1, 226m, A Stockman, P Marek 26.i.06 [MY3486, 1juv, AUMNH; MY3487, 1♀, CAS]; Leavesley Rd just E Roop Rd, 37.0574, -121.5188 1, 235m, A Stockman, P Marek 24.i.06 [MY3473, 3476-78 2♀, 1 juv., AUMNH]; Uvas Rd/G8, 7.2km S Croy Rd, 37.0599, -121.6778 1, 126m, A Stockman 11.vi.05 [MY3328-30, 2♀, 1juv, AUMNH]; Alum Rock Park, trail near Quail Hollow bridge, 37.3934, -121.8157 1, 137m, A Stockman, P Marek 25.i.06 [MY3481-83, 1♀, 2juv, AUMNH]; East Dunne Rd, SW Henry Coe State Park, vic Anderson Lake, 37.1496, -121.5909 1, 230m, M Hedin, J Starrett, D Carlson 27.iii.2010 [MY3811, 1♀, AUMNH]; Santa Cruz Co.: Ben Lomond Area, 37.077, -122.084 3, 100m, Father Koenig 1.xi.64 [AP170, 1♂, AMNH]; Hwy 9, S Brookdale, 37.1037, -122.1048 1, 130m, M Hedin, R Keith, S Thomas, J Starrett 11.iii.06 [MY3536, 1juv, AUMNH]; Mt Madonna County Park, along Mt Madonna road, 0.72km from jct Pole Line Rd, 37.0116, -121.7208 1, 455m, J Bond, M van der Merwe 15.xii.99 [MY705, 706 2♀, AUMNH]; University of California Kresge College, 36.99, -122.06 3, 227m, M Ramirez 14.x.83 [AP158, 1♂, CAS]; Bear Creek Rd 10km E Hwy 9, 37.1767, -122.063 1, 445m, A Stockman 4.vi.05 [MY3258, 1♀, AUMNH]; Henry Cowell Redwoods SP, Hwy 9, 1.8km S entrance, 37.0309, -122.0648 1, 161m, A Stockman 15.v.05 [MY3121, 1♀, AUMNH]; Hwy 35, 3.2km S of Hwy 9, 37.27828, -122.14957 1, 747m, A. Stockman 13.v.05 [MY3100, 1♀, AUMNH]; Swanton Rd, 6.3km from S entrance off hwy 1, S Swanton, 37.0644, -122.2277 1, 17m, J Bond, A Stockman, D Beamer 17.iii.05 [MY3066, 3067 1♀, 1juv, AUMNH]; Sonoma Co.: Bennett Valley Rd, 4.3km W Sonoma Mountain Rd, 38.4163, -122.661 1, 94m, A Stockman 14.vi.05 [MY3353, 1juv, AUMNH]; Mark W Springs Rd, 7.2km E Old Redwood Hwy, 38.5401, -122.7209 1, 129m, A Stockman 14.vi.05 [MY3352, 1juv, AUMNH]; Stanislaus Co.: Del Puerto Canyon Rd, 22.8km W I-5, 37.4245, -121.3425 1, 304m, A Stockman 6.vi.05 [MY3275, 1juv, AUMNH]; Del Puerto Canyon Rd, 5.9km W I-5, 37.47373, -121.236 1, 101m, A Stockman 6.vi.05 [MY3267, 3268 1♀, 1juv, AUMNH].

Variation, males (5). Cl 5.50-6.88, 6.18 ± 0.28; Cw 4.50-5.94, 5.16 ± 0.25; STRl 3.03-3.60, 3.39 ± 0.13; STRw 2.54-3.19, 2.83 ± 0.12; LBw 0.83-1.11, 0.93 ± 0.05; LBl 0.41-0.60, 0.53 ± 0.04; leg I: 5.00-6.38, 5.55 ± 0.27; 3.25-4.38, 3.72 ± 0.21; 3.28-4.44, 3.81 ± 0.21; 2.16-3.00, 2.50 ± 0.15; 1.98-2.45, 2.28 ± 0.10; leg IV: 5.00-6.31, 5.65 ± 0.28; 2.63-3.44, 2.94 ± 0.14; PTl 2.37-2.88, 2.61 ± 0.11; PTw 0.80-1.00, 0.89 ± 0.04; Bl 1.07-1.34, 1.22 ± 0.05; TSp 3-5, 3.6 ± 0.4; TSr 0-5, 3.00 ± 0.84; TSrd 4-6, 4.80 ± 0.37.

Variation, females (5). Cl 6.38-8.63, 7.27 ± 0.37 [6.88]; Cw 5.25-6.40, 5.82 ± 0.25 [5.75]; STRl 3.50-5.31, 4.19 ± 0.31; STRw 3.01-4.50, 3.64 ± 0.25; LBw 1.19-1.38, 1.25 ± 0.03; LBl 0.62-0.93, 0.79 ± 0.05; Leg I: 14.00-19.88, 16.44 ± 0.98; ANTd 6-9, 8.20 ± 0.58; PTLs 14-24, 19.40 ± 1.60; TBs 2-6, 3.80 ± 0.66.

GenBank accessions.

16S-tRNAval-12S: EU569898-EU569900, EU569905, EU569923-EU569926, EU569959-EU569963, EU569992-EU570007, EU570016-EU570018, EU570032-EU570037, JX103401-JX103421; 18S (partial)-ITS1-5.8S-ITS2: EU569884-EU569887; EU569895, EU569896.

Distribution and natural history.

Aptostichus stanfordianus is distributed widely throughout the Coastal Ranges of central California, bounded to the east by the Central Valley (Map 10). The greatest concentration of populations appears to be centered in the Santa Cruz Mountains and the Diablo and Gabilan Ranges with additional populations in the Sonoma and Howell Mountains to the north. The DM for Aptostichus stanfordianus (Map 11) corresponds closely to the known distribution of the species with the exception of areas of high probability of occurrence that overlaps considerably with the predicted distribution of Aptostichus angelinajolieae but likewise is separated from this species by an area of low probability of occurrence across the Salinas Valley. Also, populations found on the eastern facing slopes of the Coastal Range are found in areas of a low probability of occurrence. Like Aptostichus angelinajolieae , this species is found along damp, north-facing steep banks and road cuts. Populations of this species are found in a number of ecoregion types including California coastal chaparral and shrub, coastal range open woodland and shrub, coniferous forest, coastal steppe, mixed forest and redwood forest. Males have been collected early fall through late winter ( September–March).

Conservation status.

Aptostichus stanfordianus is widespread and abundant throughout its distribution and thus is likely classified as secure. Nevertheless, its distribution throughout the San Francisco Bay region has likely resulted in its extirpation from many localities; specimens from Smith’s (1908) type locality have not been collected in many years.

Species concept applied.

Cohesion (sensu Bond and Stockman 2008). Based on the evidence available at the time, Bond and Stockman (2008) considered the two Aptostichus stanfordianus clades to comprise a single ecologically interchangeable species; that is, the two sister lineages (no longer retained as such in our more recent analysis, see comments below) overlapped in their predicted distributions and thus were ecologically equivalent (not adaptively diverged).

Remarks.

Although cohesion species concept criteria were applied in the formulation of this species the subsequent addition of molecular data for more populations seems to have clouded the picture. The new data indicate that Aptostichus stanfordianus , as currently delineated, may comprise at least two distinct, unrelated lineages, within the Atomarius Sibling Species Complex (Fig. 28). As such the current diagnosis and delimitation will require reconsideration in the future if these two lineages remain genealogically exclusive under further scrutiny.