Aptostichus sierra, 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 : 151-154

Aptostichus sierra sp. n. Figures 332-336Map 34

Types.

Male holotype (AP400) from California, Fresno County, Shaver Lake, 37.1129, -119.3095 5, 1660m, coll. 12.ix.1959; deposited in AMNH.

Etymology.

The specific epithet is a noun taken in apposition from the location of the type locality in the Sierra Nevada mountain range.

Diagnosis.

All known male specimens of the Sierra species group can be distinguished from all other species of Aptostichus by virtue of having a long slender metatarsus I which lacks a ventral/proximal excavated area. Aptostichus sierra males can be distinguished from others in the Sierra species group by virtue of their large size, by having a broader sternum, and unique leg I spination pattern (Figs 333, 334, 336).

Description of male holotype.

Specimen preparation and condition. Specimen presumed to have been collected from pitfall trap, preserved in 70% EtOH. Coloration faded. Pedipalp, leg I left side removed, stored in vial with specimen. Large megaspine on tibia pedipalp left side missing, intact on right side pedipalp tibia. General coloration. Carapace, chelicerae, legs yellowish red 5YR 4/6. Abdomen uniform brown 7.5YR 5/3 dorsally, mottled dorsal chevron pattern (Fig. 332). Cephalothorax. Carapace 5.52 long, 4.50 wide, glabrous with few fine white spines, fine black spines intermingled, stout black bristles along fringe; surface smooth, pars cephalica elevated. Fringe, posterior margin with black bristles. Foveal groove deep, moderately recurved. Eyes on low mound. AER slightly procurved, PER slightly recurved. PME, AME subequal diameter. Sternum moderately setose, STRl 3.07, STRw 2.25. Posterior sternal sigilla small, positioned marginally, not contiguous, anterior sigilla pairs very small, oval, marginal. Chelicerae with distinct anterior tooth row comprising 6 teeth, posterior margin with single row of small denticles. Palpal endites with patch of small cuspules on proximal, inner margin, labium lacks cuspules, LBw 0.31, LBl 0.77. Rastellum consists of 6 stout spines arranged along anterior margin, not on prominent mound. Abdomen. Setose, heavy black setae intermingled with fine black setae. Legs. Leg I: 4.90, 3.36, 3.92, 2.68, 0.00; leg IV: 5.20, 2.75. Tarsi strongly bent. Light tarsal scopulae on all legs I, II; metatarsus I with light scopulate distally. Tarsus I with single, slightly staggered row of 17 trichobothria. Leg I spination pattern illustrated in Figures 333, 334, 336; TSp 18 with numerous additional spines dorsally, TSr 5, TSrd 0. Tibia I long relative to femur I; distal retrolateral spines absent. Metatarsus not anteverted, lacks a distinct mid–ventral mating apophysis, proximal excavation of metatarsus I. Metatarsus, tarsus I long, tarsus I lacks spines (Figs 333, 334). Pedipalp. Palpal tibia short, width slightly less than half-length. Retrolateral surface has at least one large spine, with numerous smaller, ventral elongate spines. Palpal bulb very short (Bl/Cl 13.95), pyriform. Embolus intermediate width with slight curvature at midpoint, not serrated distally (Fig. 335). PTw 0.82, PTl 1.97, Bl 0.77.

Variation. Known only from the type specimen.

Description of female.

Known only from male specimens.

Material examined.

Known only from the type specimen.

Distribution and natural history.

Aptostichus sierra is known only from the type specimen from Fresno County, collected in a pitfall trap in September. The habitat type is characterized as Sierran Steppe, Mixed Coniferous Forest, and Alpine Meadow.

Conservation status.

The conservation status of Aptostichus sierra is likely to be characterized as imperiled due to its rarity and restricted distribution.

Species concept applied.

Morphological.

Remarks.

Despite extensive searching in the areas around the type locality over the past decade, I have been unable to recover a single Aptostichus sierra specimen. This species is either very rare or I have been unable to pinpoint its exact microhabitat.