Aptostichus chiricahua, 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 : 68-69

Aptostichus chiricahua sp. n. Figures 142-145Map 1

Type.

Male holotype (AP645) from Arizona, Cochise County, Portal, 31.91369, -109.1408 1, 1450m, coll. S. Bennett 12.ix.1980; deposited in AMNH.

Etymology.

The specific epithet is a noun taken in apposition from the type locality, the Chiricahua Mountains of southeastern Arizona.

Diagnosis.

Males can be diagnosed on the basis of a unique conformation of the tibia leg I, spination pattern which comprises numerous spines on the prolateral and distal surfaces (Figs 142-144). This spination pattern is most similar to the Channel Islands species Aptostichus nateevansi , however the Aptostichus chiricahua type specimen has considerably more spines, two rows, along the distal, prolateral aspects of the mating clasper tibia. A considerable geographic distance separates Aptostichus chiricahua and Aptostichus nateevansi . The geographical proximate species, Aptostichus edwardabbeyi , has dissimilar mating clasper morphology and has a distinct offset prolateral rastellar spine and thus is a Hesperus group species.

Description of male holotype.

Specimen preparation and condition. Specimen presumably collected live, wandering, preserved in 70% EtOH. Pedipalp, leg I left side removed, stored in vial with specimen; leg IV left side missing. General coloration. Carapace, chelicerae, dark reddish brown 2.5YR 2.5/4. Abdomen yellowish red 5YR 4/6, distinct mottled dorsal markings. Cephalothorax. Carapace 6.25 long, 5.10 wide, hirsute with intermingled thin white, black setae; stout black bristles along fringe; surface smooth, pars cephalica elevated. Fringe, posterior margin with black bristles. Foveal groove deep, straight. Eyes elevated on high mound. AER slightly procurved, PER strongly recurved. PME, AME subequal diameter. Sternum moderately setose, STRl 3.35, STRw 2.88. Posterior sternal sigilla moderate in size, positioned towards margin, not contiguous, anterior sigilla pairs small, oval, marginal. Chelicerae with distinct anterior tooth row comprising 6 teeth, posterior margin with patch of small denticles. Palpal endites with patch of small cuspules on proximal, inner margin, labium with 2 cuspules, LBw 0.94, LBl 0.65. Rastellum consists of 5 stout spines not on prominent mound. Abdomen. Setose, heavy black setae intermingled with fine black setae. Legs. Leg I: 5.60, 3.88, 3.80, 2.48, 2.33; leg IV: 5.55, 2.92. Tarsus I, slender, tarsus IV straight. Light tarsal scopulae on all legs, light scopulae on metatarsus I, II. Tarsus I with single, slightly staggered row of 12 trichobothria. Leg I spination pattern illustrated in Figures 142-144 comprising heavy spination on the patella, tibia, metatarsus; TSp 5, TSr 4, TSrd 3. Pedipalp. Articles slender, lacking distinct spines (Fig. 145). PTw 0.85, PTl 2.57, Bl 1.11. Embolus broad, tapering sharply toward tip, lacking serrations (Fig. 145).

Variation. Known only from the type specimen.

Description of female.

Known only from male specimens.

Material examined.

Known only from the type material.

Distribution and natural history.

Aptostichus chiricahua is known only from a single specimen taken from the type locality in Arizona, Cochise Co., Portal (Map 1). Despite extensive collecting efforts in the area female burrows have never been observed. Based on the paucity of specimens, the species may be quite rare.

Conservation status.

Undetermined but likely to be imperiled given its restricted distribution and rarity in collections.

Species concept applied.

Morphological.

Remarks.

As noted above in the description of Aptostichus nateevansi , Aptostichus chiricahua has a mating clasper that is very similar to the California Channel Island species and thus may be closely related despite the disjunct distribution.