Difference between revisions of "Aptostichus killerdana"

Latest revision as of 09:53, 20 December 2012

Taxonavigation

Ordo: Araneae
Familia: Euctenizidae
Genus: Aptostichus

Name

Aptostichus killerdana Bond, 2012 sp. n. – Wikispecies link – Killerdana Trapdoor Spider’ ZooBank link – Pensoft Profile

Types

Female holotype and male paratype (AP432) from California, Orange County, Salt Creek, 2.4km North of Dana Point, 33.4819, -117.72063, 21m, coll. W. Icenogle 14.xi.1969, deposited in the AMNH.

Etymology

The specific epithet is a noun in apposition taken from the name of the legendary surf break, “Killer Dana”, that once graced the shore of Dana Point. The break was destroyed in the mid 1960’s by the construction of the breakwater for Dana Point Harbor.

Diagnosis

Males can be distinguished from other known related species of Aptostichus (e.g., Aptostichus cahuilla) by virtue of a unique tibia I TSrd spination pattern that comprises only a few spines (Fig. 210). In contrast, the spination pattern of Aptostichus cahuilla is formed of many overlapping distal spines. Females (Fig. 213) can be distinguished on the basis of having long median spermathecal stalks that do not curve as extensively and a median bulb that is larger (Fig. 214) than that of Aptostichus cahuilla; specimens also tend to have a larger number of labial cuspules (> 3).

Description of female holotype

Specimen preparation and condition. Female collected live from burrow, preserved in 70% EtOH. Genital plate removed, cleared in trypsin, stored in microvial with specimen. General coloration. Carapace, legs, chelicerae, dark yellowish brown 10YR 4/6. Abdomen lighter in color with distinct mottled striping (Fig. 213), ventral aspect, spinnerets pale yellow. Cephalothorax. Carapace 4.75 long, 4.10 wide, generally glabrous with few light dark, thin setae; smooth surface, pars cephalica moderately elevated. Fringe lacks setae, with dark purple coloration along margins. Foveal groove deep, slightly procurved to straight. Eye group elevated on low mound. AER slightly procurved, PER slightly recurved. PME, AME subequal diameter. Sternum widest at coxae II/III, moderately setose, STRl 3.08, STRw 2.65. Three pairs of sternal sigilla anterior pairs small, oval, marginal, posterior small, somewhat irregular shaped/elongate, positioned at midpoint from margin to center. Chelicerae anterior tooth row comprising 6 teeth with posterior margin denticle patch comprising two rows. Palpal endites with 28 cuspules concentrated at the inner (promargin) posterior heel; labium with 7 cuspules, LBw 0.97, LBl 0.51. Rastellum consists of 7 stout spines not positioned on mound, one spine separated laterally; 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 10.63 long. Tarsus I with single staggered row of 11 trichobothria. Pedipalp, leg I moderately heavy scopulae, lighter on leg II; extends to distal aspect of leg I tibia, only on tarsus, metatarsus of leg II; sparse scopulae on tarsus of legs III, IV. PTLs 16, TBs 3. Rudimentary preening comb on retrolateral distal surface (at tarsus - metatarsus joint) of metatarsus III, VI. Spermathecae. Simple, small spermathecal bulbs with elongate sclerotized stalk, with small laterally basal extension (Fig. 214).
Variation (3). Cl 4.20-4.85, 4.60±0.20; Cw 3.45-4.10, 3.88±0.22; STRl 2.70-3.18, 2.99±0.15; STRw 2.00-2.65, 2.38±0.2; LBw 0.80-1.00, 0.92±0.06; LBl 0.50-0.60, 0.54±0.03; Leg I: 9.10-10.75, 10.16±0.53; ANTd 5-6, 5.67±0.33; PTLs 9-16, 11.33±2.33; TBs 2-3, 2.67±0.33.

Description of male paratype

Specimen preparation and condition. Specimen collected live from burrow, preserved in 70% EtOH but subsequently dried; generally in poor condition. Pedipalp, leg I left side removed, stored in vial with specimen, molt removed from burrow bottom. Cephalothorax. Carapace 4.24 long, 3.56 wide, lightly hirsute with thin white spines, stout black bristles along fringe; surface smooth, pars cephalica elevated. Fringe, posterior margin with black bristles. Foveal groove deep, slightly recurved, almost forming a pit. Eyes on low mound. AER slightly procurved, PER slightly recurved. PME, AME subequal diameter. Sternum moderately setose, STRl 2.50, STRw 2.10. Posterior sternal sigilla positioned at margin, not contiguous, anterior sigilla pairs 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 with 5 cuspules, LBw 0.82, LBl 0.43. Rastellum consists of 5 stout spines not on prominent mound. Abdomen. Setose, heavy black setae intermingled with fine black setae. Legs. Leg I: 4.12, 3.10, 2.70, 1.75, 1.58; leg IV: 4.05, 2.10. Light tarsal scopulae on legs I, II. Tarsus I with single, slightly staggered row of 13 trichobothria. Leg I spination pattern illustrated in Figures 210, 211; TSp 3, TSr 1, TSrd 3. Pedipalp. Articles stout, lacking distinct spines (Fig. 212). PTw 0.9, PTl 1.9, Bl 1.1. Embolus slender, with slight curvature at tip (Fig. 212).
Variation. Known only from the type specimen.

Material examined

United States: California: Orange Co.: Salt Creek 2.4km N Dana Pt, 33.4819, -117.72063, 21m, W Icenogle 14.xi.1969 [AP432, 1♀, 1♂, AMNH], 12.xi.1969 [AP604, 1♀, 2juv, AMNH], 14.xi.1969 [AP606, 1♀, 10juv, CAS], S Johnson 15ii.1971 [AP607, 1♀, 1juv, AMNH].

Distribution and natural history

Aptostichus killerdana is known only from the type locality in Orange County. The species was collected from a relatively low-lying, riparian habitat in the time interval from 1969-1971. Some point thereafter the area was developed and is now Monarch Beach Golf Links; the habitat was cleared and is now a golf course. Although classified as California coastal chaparral and scrub, photographs of the area prior to development seem to indicate that it was a relatively unique and pristine coastal riparian habitat. The location was also the southernmost known locality for Apomastus kristenae Bond, 2004, likewise a species that seems to have extirpated from the area. Extensive sampling in the low-lying areas around and above the golf resort has to date proven unsuccessful.

Species concept applied

Aptostichus killerdana is presumed extinct.

Original Description

• Bond, J; 2012: Phylogenetic treatment and taxonomic revision of the trapdoor spider genus Aptostichus Simon (Araneae, Mygalomorphae, Euctenizidae) ZooKeys, 252: 1-209. doi

Images

Figures 210–214. Aptostichus killerdana sp. n. (AP432) from Orange County. 210–212 male paratype; scale bars = 1.0mm 210 retrolateral aspect, leg I [806062] 211 prolateral aspect, leg I [806066] 212 retrolateral aspect, pedipalp [806068] 213, 214 female holotype 213 habitus [806070] 214 cleared spermathecae [806703]; scale bar = 0.1mm.  Maps 25, 26. Aptostichus killerdana sp. n. (filled square), Aptostichus serrano sp. n. (filled circles), Aptostichus chemehuevi sp. n. (filled triangles). 25 known distributions 26 predicted distribution of Aptostichus serrano; cooler colors–blue shades–represent areas of high probability of occurrence, warmer colors–yellow and orange shades–represent areas of low probability of occurrence.