Aptostichus nateevansi, 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 : 65-67

Aptostichus nateevansi sp. n. Figures 134-141Map 1

Types.

Male holotype (AP420) from California, Los Angeles County, Santa Catalina Island, Toyon Bay, 33.37079, -118.34963 4, 1m, coll. S. Bennett 1.xi.87, deposited in CAS. Male (AP429) and female (AP421) paratypes from California, Los Angeles County, San Clemente Island, 32.878, -118.46417 4, 500m, coll. R. Felger, P. Regal 2.v.65 and J. Scott 1.vi.38; deposited in CAS and AMNH respectively.

Etymology.

The specific epithet is patronym in honor of Nathaniel Evans in recognition of the Evans family support of biodiversity research at East Carolina University, Greenville, North Carolina.

Diagnosis.

Males (Fig. 134) can be distinguished having a distinctive row of spines on the prolateral surface of patella I (Figs 136, 138, 139). Females can be tentatively distinguished from all species, except some Aptostichus atomarius individuals, by having a large number of anterior margin denticles (ANTd= 8).

Description of male holotype.

Specimen preparation and condition. Specimen preserved in 75% ethanol, coloration faded. Pedipalp, leg I left side removed stored in vial with specimen. General coloration. Carapace, chelicerae, legs dark reddish brown 5YR 3/4. Abdomen uniform reddish brown 5YR 4/3 dorsally, ventrum, spinnerets pale yellow. Cephalothorax. Carapace 6.44 long, 5.44 wide, hirsute with thin white setae, stout black bristles along fringe; surface smooth, pars cephalica elevated slightly. Fringe, posterior margin with black bristles. Foveal groove deep, moderately straight to slightly recurved. Eyes on low mound. AER straight, PER slightly recurved. PME, AME subequal diameter. Sternum moderately setose, STRl 3.44, STRw 2.75. Posterior sternal sigilla small, heavily sclerotized, positioned towards mid sternum, not contiguous, anterior sigilla pairs small, oval, marginal. Chelicerae with distinct anterior tooth row comprising 8 teeth, posterior margin with single row of small denticles. Palpal endites with patch of small cuspules on proximal, inner margin, labium lacks cuspules, LBw 1.36, LBl 0.68. Rastellum consists of five stout spines arranged along anterior margin. Abdomen. Setose, heavy black setae intermingled with fine black setae. Legs. Leg I: 5.94, 4.06, 4.06, 2.44, 2.28; leg IV: 5.88, 3.06. Light tarsal scopulae on legs I, II. Tarsus I with single, slightly staggered row of 12 trichobothria. Leg I spination pattern illustrated in Figures 135-139; TSp 8, TSr 7, TSrd 5; numerous spines on patella prolateral surface. Pedipalp. Articles slender, lacking distinct spines (Fig. 140). PTw 0.84, PTl 2.70, Bl 1.28. Embolus slender, tapering gradually toward tip, lacks serrations (Fig. 140).

Variation (2). Cl 6.31-6.44, Cw 5.19-5.44, STRl 3.29-3.44, STRw 2.75-2.79, LBw 0.95-1.36, LBl 0.65-0.68, leg I: 5.45-5.94, 3.7-4.06, 3.75-4.06, 2.25-2.44, 2.25-2.28; leg IV: 5.35-5.88, 2.75-3.06; PTl 2.50-2.70, PTw 0.84-0.92, Bl 1.28-1.28, TSp 5-8, TSr 4-7, TSrd 5-5.

Description of female paratype.

Specimen preparation and condition. Female collected from burrow, prepared in same manner as male holotype. Genital plate removed stored in microvial with specimen. Color. Carapace, legs, chelicerae, dark reddish brown 2.5YR 2.5/4; abdomen uniform reddish brown dorsally 5YR 4/4, ventral aspect, spinnerets pale yellow. Cephalothorax. Carapace 7.39 long, 6.50 wide, lightly hirsute; 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 4.50, STRw 3.94. Three pairs of sternal sigilla, anterior pairs small, oval, marginal, posterior pair larger, oval, mesially positioned. Chelicerae anterior tooth row comprising 8 teeth with posterior margin denticle patch. Palpal endites with 48 cuspules concentrated at inner (promargin) posterior heel; labium with 6 cuspules, LBw 1.34, LBl 0.84. Rastellum consists of 5 very stout spines positioned along the anterior margin, not on mound; 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 17.76 long. Tarsus I with single staggered row of 11 trichobothria. Legs I, II with moderately heavy scopulae on tarsi, metatarsi. PTLs 9, TBs 3. Distinct preening combs lacking on legs III, IV. Spermathecae. Intermediate sized median stalk with larger terminal bulb; median stalk heavily sclerotized along its entire length. Basal extension well developed as distinct auxiliary bulb (Fig. 141).

Variation (2). Cl 7.00-7.39, Cw 5.70-6.50, STRl 4.25-4.50, STRw 3.70-3.94, LBw 1.26-1.34, LBl 0.84-0.85, Leg I: 17.45-17.76, ANTd 8-8, PTLs 9-12, TBs 3-4.

Material examined.

United States: California: Alameda Co.: Sunol Regional Wilderness Area, 37.5202, -121.8261 3, 220m, M Thompson 31.xii.1980 [AP610, 1♂, AMNH]; Los Angeles Co.: Toyon Bay, Santa Catalina Island, 33.3708, -118.3496 4, 1m, S Bennett 27.x.1979 [AP419, 1♂, CAS], 1.xi.1981 [AP420, 1♂, AMNH]; San Clemente Island, 32.878, -118.4641 6, 500m, J Scott 1.vi.1938, [AP421, 1♀, AMNH), R Felger, P Regal 2.v.1965 [AP429, 1♂, AMNH], A Menke 14.v.1973, [AP543, 1♀, AMNH), J Doyen 21.v.1972 [AP544, 1juv, CAS].

Distribution and natural history.

Aptostichus nateevansi is known primarily from Los Angeles County, Channel Islands of Santa Catalina and San Clemente (see comments below regarding the Alameda County specimen). The primary habitat is California coastal chaparral forest and shrub.

Conservation status.

Few specimens of this species have ever been collected, and none within the last quarter century; it is known from only a few localities. The Catalina Island Conservancy manages most of Santa Catalina Island and the United States Navy owns San Clemente Island which may afford the species some protection. Nevertheless, I would consider the status of this species likely imperiled due to low abundance and rarity in collections.

Species concept applied.

Morphological.

Remarks.

Despite the geographical distance that separate the type locality and Alameda County, the anomalous specimen from the Sunol Regional Wilderness area is placed as part of the Aptostichus nateevansi species construct because the mating clasper and somatic morphology of the specimen is indistinguishable from those of other specimens. I have little doubt that this is a related, yet disjunct sister species (like Aptostichus chiricahua , below), but have chosen to conservatively wait until more specimens are available to set the Alameda County specimen aside as a separate species.