Aptostichus aguacaliente, Bond, Jason E., 2012

Bond, Jason E., 2012, Phylogenetic treatment and taxonomic revision of the trapdoor spider genus Aptostichus Simon (Araneae, Mygalomorphae, Euctenizidae), ZooKeys 252, pp. 1-209 : 112-117

Aptostichus aguacaliente sp. n. Figures 220-227Map 27, 28

Types.

Male holotype and female paratype (AP393) from California, Riverside County, Windy Point, 8km NW of Palm Springs on HWY 111, 33.8964, -116.6251 1, 488m, coll. W. Icenogle 15.i.1969 deposited in CAS.

Etymology.

The specific epithet is a noun in apposition taken from the Agua Caliente Band of the Cahuilla Native American Tribal group of Palm Springs, California.

Diagnosis.

Males (Fig. 220) of this species can be diagnosed on the basis of a unique conformation of the spination pattern of tibia I which consists of 3-5 long spines, sometimes overlapping, and by having a low tibia I apophysis that bears a spine (Figs 221, 223). Females can be distinguished by having a median spermathecal stalk that is sinuous and 8-9 times longer than wide (Figs 225-227). Males and females have features that are similar to Aptostichus hesperus : large sternal sigilla that are mid-ventrally positioned and a rastellum that consists of at least 6 enlarged spines with one offset prolaterally. However, Aptostichus aguacaliente sigilla are not contiguous and this species’ cephalothorax and abdominal coloration is very light (Figs 220, 224). Aptostichus hesperus coloration is much darker with a more distinctive abdominal banding pattern. Aptostichus aguacaliente males also tend to be smaller in size than Aptostichus hesperus males; however there is no discontinuous size difference between females of these two species.

Description of male holotype.

Specimen preparation and condition. Specimen collected live from under debris, preserved 70% EtOH. Coloration slightly faded. Pedipalp, leg I left side removed, stored in vial with specimen. General coloration. Carapace, chelicerae, legs yellowish brown 10YR 5/6. Abdomen uniform very pale brown 10YR 7/4, dark mid dorsal band markings (Fig. 220). Cephalothorax. Carapace 4.40 long, 3.63 wide, generally glabrous with sparse thin setae, stout long black bristles on posterior fringe; pars cephalica elevated. Foveal groove deep, straight. Eyes on low mound. AER straight, PER slightly recurved. PME, AME subequal diameter. Sternum moderately setose, STRl 2.32, STRw 2.10. Posterior sternal sigilla large, positioned centrally, not contiguous, anterior sigilla pairs small, oval, marginal. Chelicerae with distinct anterior tooth row comprising 7 teeth, posterior margin with single row of small denticles. Palpal endites with patch of small cuspules on proximal, inner margin, labium with 2 cuspules, LBw 0.77, LBl 0.48. Rastellum consists of 5 stout spines not on mound. Abdomen. Setose, heavy black setae intermingled with fine black setae. Legs. Leg I: 4.45, 3.20, 2.79, 1.90, 1.55; leg IV: 4.00, 2.00. Light tarsal scopulae on legs I, II. Tarsus I with single, slightly staggered row of 8 trichobothria. Leg I spination pattern illustrated in Figures 221, 223; TSp 4, TSr 2, TSrd 4; mid-ventral metatarsus mating apophysis bearing a single blunt spine. Pedipalp. Articles stout, lacking distinct spines (Fig. 222). PTw 0.87, PTl 1.88, Bl 1.02; palpal bulb long relative to carapace length; embolus slender, with slight distal curvature (Figs 222).

Variation (10). Cl 3.94-5.00, 4.57 ± 0.12; Cw 3.19-4.31, 3.80 ± 0.12; STRl 2.19-2.94, 2.52 ± 0.09; STRw 1.80-2.56, 2.18 ± 0.08; LBw 0.62-0.80, 0.73 ± 0.02; LBl 0.38-0.60, 0.46 ± 0.02; leg I: 4.19-5.38, 4.75 ± 0.13; 2.81-3.75, 3.33 ± 0.10; 2.56-3.38, 2.97 ± 0.09; 1.71-2.16, 1.97 ± 0.05; 1.14-1.74, 1.51 ± 0.06; leg IV: 3.75-4.81, 4.28 ± 0.12; 1.88-2.31, 2.13 ± 0.05; PTl 1.77-2.34, 2.05 ± 0.06; PTw 0.78-0.99, 0.91 ± 0.02; Bl 0.96-1.13, 1.04 ± 0.02; TSp 3-7, 4.50 ± 0.37; TSr 2-7, 4.50 ± 0.5; TSrd 3-5, 3.50 ± 0.22.

Description of female paratype.

Specimen preparation and condition. Female collected live from burrow, prepared in same manner as male holotype. Genital plate removed, cleared in trypsin, stored in microvial with specimen. General coloration. Carapace, legs, chelicerae, dark yellowish brown 10YR 4/6. Abdomen uniform yellowish brown 10YR 5/4, markings similar to male (Fig. 224). Cephalothorax. Carapace 5.75 long, 4.88 wide, glabrous; generally smooth surface, pars cephalica moderately elevated. Fringe lacks setae. Foveal groove deep, procurved. Eye group slightly elevated on low mound. AER slightly procurved, PER slightly recurved. PME-AME subequal diameter. Sternum widest at coxae II/III, moderately setose, STRl 3.64, STRw 3.04. Three pairs of sternal sigilla, anterior pairs small, oval, marginal, posterior pair much larger, oval, mesially positioned but not contiguous. Chelicerae anterior tooth row comprising 8 teeth with posterior margin denticle patch comprising two short rows of teeth. Palpal endites with 55 cuspules concentrated at inner (promargin) posterior heel; labium with 3 cuspules, LBw 1.19, LBl 0.68. Rastellum consist of 6 very stout spines not positioned on mound, one spine offset prolaterally; fringe of short spines along distal promargin extending upward from rastellum. Abdomen. Moderately setose. PLS all 3 segments with spigots. Terminal segment 1/2 length of medial segment, 2 enlarged spigots visible at tip. PMS single segment, with spigots, short with rounded terminus. Legs. Anterior two pairs noticeably more slender than posterior pairs. Leg I 14.19 long. Tarsus I with single staggered row of 12 trichobothria. Legs I, II, with moderately heavy scopulae on tarsi, metatarsi; light scopulae on tarsi III, IV. PTLs 7, TBs 4. Distinct preening comb on retrolateral distal surface (at tarsus - metatarsus joint) of metatarsus III, IV. Spermathecae. 2 simple spermathecal bulbs with long, curved sclerotized median stalk, medial aspect runs parallel to genital lip before turning towards anterior (Figs 225-227). Basal extension lacks well-developed, distinct bulb.

Variation (10). Cl 5.00-6.69, 5.82 ± 0.19; Cw 3.88-5.69, 4.87 ± 0.19; STRl 3.00-4.25, 3.61 ± 0.15; STRw 2.52-3.69, 3.10 ± 0.12; LBw 0.98-1.35, 1.13 ± 0.05; LBl 0.56-0.75, 0.69 ± 0.02; Leg I: 12.19-17.13, 14.40 ± 0.53; ANTd 6-9, 6.80 ± 0.33; PTLs 7-11, 8.70 ± 0.52; TBs 3-5, 4.10 ± 0.28.

Material examined:

United States: California: Imperial Co.: 12.9km SE Niland, between Coachella Canal & Railroad, 33.192, -115.3933 4, 26m, W Icenogle, T Prentice 22.ii.1996 [AP275, 1♀, 1juv, CAS]; Riverside Co.: Carrizo Creek, 6.4km S Palm Desert, 33.6264, -116.4215 3, 1000m, D Bixler 27.ii.68 [AP216, 1juv, AMNH], W Icenogle 28.viii.1968 [AP213, 217, 218, 1♂, 2♀, 28juv, AMNH], 1.iv.1969 [AP219, 4juv, AMNH]; 16km W Chiriaco Summit on I-10, 33.6697, -115.9129 3, 433m, R Vetter 1.iv.1997 [AP204, 205, 2♂, UCR]; 6.1km S Palm Desert, 33.6837, -116.4038 3, 244m, S Telford 24.iii.1962 [AP208, 1♂, CAS]; 6.1km N Rancho Mirage, 33.8271, -116.4088 4, 79m, W Icenogle 16.xi.1968 [AP066, 1♀, AMNH]; Off Gene Autry Rd, Whitewater Flood Plain Preserve, 33.87457, -116.5134 1, 162m, J Bond 5.ii.2004 [MY2504, 1juv, AUMNH]; Palm Springs, Windy Point, 33.8908, -116.6302 1, 325m, J Bond 24.i.1997 [AP720, 1♀, AUMNH]; Palm Springs, Windy Point, 33.8909, -116.6304 1, 378m, J Bond 23.i.1997 [AP1205, 1207, 1220, 1233, 1234, 4juv, 1♀, AUMNH]; Windy Point, 33.8943, -116.6235 1, 306m, J Bond, W Icenogle 28.i.2004 [MY2473, 1juv, AUMNH]; Santa Rosa Mountains, W side Windy Pt, ~1km SSW Tipton Rd & hwy 111 junction, 33.8956, -116.6481 1, 344m, T Prentice 18.ii.2003 [AP1230, 1♂, UCR]; Windy Point, 8km NW Palm Springs on hwy 111, 33.8964, -116.6251 3, 488m, W Icenogle, G Polis 7.ii.1976 [AP224-226, 3♀, CAS], [AP211, 223 1♂, 1♀, AMNH], G Ballmer 18.ii.1989 [AP600, 1♀, UCR], W Icenogle 15.i.1969 [AP210, 214, 228-231, 393, 10♀, 4♂, 27juv, CAS], [AP220, 1♀, AMNH], 13.iii.1968 [AP215, 1♀, AMNH], 27.i.1969, [AP206, 1♂, AMNH], 8.ii.1970 [AP212, 1♂, AMNH], 1.i.1972 [AP209, 4♂, AMNH], M Irwin 15.viii.1968 [AP574, 1juv, AMNH], S Johnson 18.ii.1976 [AP207, 1♂, AMNH], J Bond 16.i.1997 [AP1232, 1♂, AUMNH]; Windy Pt Area, Snow Creek Rd exit off hwy 111, 33.9109, -116.6757 1, 342m, J Bond 5.ii.2004 [MY2502, 2508, 2509, 2515, 2519, 2♀, 3juv., AUMNH]; San Bernardino Co.: N Yucca Valley, NE of Water Canyon, S of Skyline Ranch Rd, 34.1451, -116.4515 1, 1244m, USGS-BRD San Diego Sta. 1.iii.2002 [AP1244, 1♂, CAS]; Granite Mtns Preserve, 34.7844, -115.6579 1, 1317m, R Vetter, J Bond 15.xii.97 [AP680, 1♂, AUMNH].

GenBank accession.

16S-tRNAval-12S: JX103235-JX103242

Distribution and natural history.

Aptostichus aguacaliente is distributed primarily throughout Colorado Desert habitat in the low-lying ridges surrounding the Imperial Valley (Map 27). County records comprise San Bernardino, Riverside, and Imperial. The DM (Map 28) appears to considerably overpredict the occurrence of Aptostichus aguacaliente in areas to the west in Riverside County and into eastern San Diego County but otherwise corresponds to the known distribution. Based on the DM, it was likely that the species was more widely distributed throughout the Imperial Valley and areas to its north prior to the extensive agricultural development that has occurred in the region. Males appear to wander in the late winter, early spring, January–February. Female burrows can be detected during the winter months often after soaking rains when individuals extend their burrow leaving a small mound of soil at the burrow entrance.

Conservation status.

The conservation status of Aptostichus aguacaliente is likely classified as secure. However, the species is presumed to be extirpated from the type locality (Windy Point, Palm Springs) as a consequence of recent construction of a golf course and housing development.

Species concept applied.

Morphological/Phylogenetic.