Taxonomic revision of the tarantula genus Aphonopelma Pocock, 1901 (Araneae, Mygalomorphae, Theraphosidae) within the United States
Author
Hamilton, Chris A.
Author
Hendrixson, Brent E.
Author
Bond, Jason E.
text
ZooKeys
2016
560
1
340
http://dx.doi.org/10.3897/zookeys.560.6264
journal article
http://dx.doi.org/10.3897/zookeys.560.6264
1313-2970-560-1
F4C1691C13584FA9A031E305DEE2B6A2
Taxon classification Animalia Araneae Theraphosidae
Aphonopelma anax (Chamberlin, 1940)
Figures 9, 10, 11, 12, 13, 14, Suppl. material 4
Dugesiella anax
Chamberlin, 1940: 34; male holotype and female allotype from Kingsville, Kleberg Co., Texas, 27.515869 -97.856109 5, elev. 58ft., no collecting date, coll. Prof. J.C. Cross; 3 female paratypes from Harlingen, Cameron Co., Texas, 26.190631 -97.696103 5, elev. 40ft., 1939, coll. Bryce Brown; deposited in AMNH. [examined]
Rhechostica anax
Raven, 1985: 149.
Aphonopelma anax
Smith, 1995: 71.
Aphonopelma breenei
Smith, 1995: 78; female holotype from Harlingen, Cameron Co., Texas, 26.190631 -97.696103 5, elev. 40ft., 1939, coll. Bryce Brown; deposited in AMNH. [examined] syn. n.
Diagnosis.
Aphonopelma anax
(Fig. 9) is a member of the
Hentzi
species group and can be identified by a combination of morphological, molecular, and geographic characteristics. Nuclear DNA identifies
Aphonopelma anax
as a phylogenetically distinct monophyletic lineage (Fig. 8), supported as the sister lineage to
Aphonopelma hentzi
, and closely related to
Aphonopelma armada
. Male
Aphonopelma anax
can be distinguished from geographically proximate species by their unique palpal bulbs - stout and wide with distinct keels on the embolus (Fig. 10). Females can be distinguished from geographically proximate species by their unique spermathecae - short, wide, slightly rounded, without capitate bulbs (Figs 12-13). Significant measurements that distinguish male
Aphonopelma anax
from its closely related phylogenetic and syntopic species are Cl, M3, and F4. Male
Aphonopelma anax
can be distinguished by possessing a larger F4/M4 (≥0.94; 0.94-1.04) than
Aphonopelma armada
(≤0.92; 0.86-0.92); a larger Cl/M1 (≥1.36; 1.36-1.63) than
moderatum
(≤1.30; 1.13-1.30) and
Aphonopelma moellendorfi
sp. n. (≤1.31; 1.10-1.31); and a larger F1/M3 (≥1.28; 1.28-1.43) than
Aphonopelma gabeli
(≤1.24; 1.18-1.24). There are no significant measurements that separate male
Aphonopelma anax
from
Aphonopelma hentzi
. Significant measurements that distinguish female
Aphonopelma anax
from its closely related phylogenetic and syntopic species are P1 and T3. Female
Aphonopelma anax
can be distinguished by possessing a larger P1/T3 (≥13.88; 13.88-19.15) than
Aphonopelma armada
(≤13.84; 9.93-13.84) and
Aphonopelma moderatum
(≤13.12; 8.14-13.12). There are no significant measurements that separate female
Aphonopelma anax
from
Aphonopelma gabeli
or
Aphonopelma hentzi
. Females of
Aphonopelma moellendorfi
are unknown and cannot be compared.
Figure 9.
Aphonopelma anax
(Chamberlin, 1940) specimens, live photographs. Female (L) - APH_0524; Male (R) - APH_3122.
Figure 10.
Aphonopelma anax
(Chamberlin, 1940).
A-I
male specimen, APH_0924 A dorsal view of carapace, scale bar = 5mm B prolateral view of coxa I C dorsal view of femur III D ventral view of metatarsus III, scale bar = 4mm E ventral view of metatarsus IV, scale bar = 4mm F prolateral view of L pedipalp and palpal tibia, scale bar = 3mm G dorsal view of palpal bulb H retrolateral view of palpal bulb, scale bar = 1mm I prolateral view of tibia I (mating clasper), scale bar = 6mm.
Figure 11.
Aphonopelma anax
(Chamberlin, 1940).
A-E
female specimen, APH_0857 A dorsal view of carapace, scale bar = 8mm B prolateral view of coxa I C ventral view of metatarsus III, scale bar = 4mm D ventral view of metatarsus IV, scale bar = 5.5mm E prolateral view of L pedipalp and palpal tibia.
Figure 12.
Aphonopelma anax
(Chamberlin, 1940).
A-H
cleared spermathecae A
anax
allotype B
breenei
holotype C
harlingenum
paratype D APH_0056 E APH_0529 F APH_0857 G APH_0858 H APH_0859.
Figure 13.
Aphonopelma anax
(Chamberlin, 1940).
A-E
cleared spermathecae A APH_0871 B APH_0899 C APH_0902 D APH_1278 E APH_1280.
Descriptions.
Male and female originally described by
Chamberlin (1940)
.
Redescription of male exemplar
(APH_0924; Fig. 10). Specimen preparation and condition: Specimen collected live crossing road, preserved in 80% ethanol; deposited in AUMNH; original coloration faded due to preservation. Left legs I, III, IV, and left pedipalp removed for measurements and photographs; stored in vial with specimen. Right leg III removed for DNA and stored at -80°C in the AUMNH (Auburn, AL). General coloration: Generally black or faded to brown. Cephalothorax: Carapace 19.10 mm long, 18.28 mm wide; densely clothed with brown/golden iridescent pubescence appressed to surface; fringe covered in long setae not closely appressed to surface; foveal groove medium deep and straight to slightly procurved; pars cephalica region rises gradually from foveal groove, gently arching anteriorly toward ocular area; AER
slightly
procurved, PER recurved; normal sized chelicerae; clypeus extends forward on a very slight curve; LBl 2.96, LBw 2.94; sternum hirsute, clothed with short length black, densely packed setae. Abdomen: Densely clothed in short black pubescence with numerous longer, lighter setae interspersed (generally red or orange in situ); dense dorsal patch of black Type I urticating bristles (
Cooke et al. 1972
). Legs: Thick and hirsute; densely clothed in short black/brown pubescence. Metatarsus I slightly curved. F1 18.77; F1w 4.74; P1 8.10; T1 14.69; M1 13.41; A1 9.23; F3 15.19; F3w 4.61; P3 6.75; T3 12.07; M3 13.77; A3 9.42; F4 18.58; F4w 4.8; P4 8.16; T4 14.50; M4 19.51; A4 11.15; femur III is normal - not noticeably swollen or wider than other legs. All tarsi fully scopulate. Extent of metatarsal scopulation: leg III (SC3) = 68.9%; leg IV (SC4) = 43.4%. Two ventral spinose setae on metatarsus III; six ventral spinose setae on metatarsus IV. Coxa I: Prolateral surface a mix of fine, hair-like and medium tapered setae. The interior face of the retrolateral branch of the tibial apophyses possesses a very large megaspine that projects anteriorly. Pedipalps: Hirsute; densely clothed in the same setal color as the other legs, with numerous longer ventral setae; one spinose seta at the apical, prolateral femur and three spinose setae on the prolateral tibia; PTl 9.45, PTw 2.90. When extended, embolus tapers and rapidly curves up and to the retrolateral side near apex; embolus wide and thick, with smooth dorsal and ventral keels.
Variation (11).Cl 14.371-21.97 (17.885
+/-
0.7), Cw 13.32-19.84 (16.557
+/-
0.62), LBl 1.96-2.96 (2.341
+/-
0.09), LBw 2.16-3.02 (2.711
+/-
0.08), F1 14.1-19.3 (16.839
+/-
0.55), F1w 3.52-5.1 (4.392
+/-
0.15), P1 6.12-8.1 (7.105
+/-
0.22), T1 11.32-15.71 (13.314
+/-
0.39), M1 9.69-13.43 (11.878
+/-
0.4), A1 6.9-9.6 (8.499
+/-
0.28), L1 length 48.47-65.97 (57.635
+/-
1.73), F3 11.39-16.14 (13.868
+/-
0.48), F3w 3.41-5.03 (4.132
+/-
0.16), P3 4.86-7.65 (6.035
+/-
0.27), T3 7.91-12.16 (10.428
+/-
0.43), M3 9.89-14.89 (12.572
+/-
0.49), A3 6.93-9.45 (8.291
+/-
0.27), L3 length 41.32-59.2 (51.194
+/-
1.82), F4 13.52-19.31 (16.56
+/-
0.58), F4w 3.22-4.83 (4.094
+/-
0.17), P4 5.5-8.16 (6.647
+/-
0.26), T4 11.15-15.56 (13.676
+/-
0.41), M4 13.66-19.69 (17.13
+/-
0.58), A4 8.1-11.15 (9.504
+/-
0.3), L4 length 52.79-72.08 (64.171
+/-
1.92), PTl 7.187-10.136 (8.709
+/-
0.27), PTw 2.246-3.32 (2.882
+/-
0.09), SC3 ratio 0.607-0.805 (0.713
+/-
0.02), SC4 ratio 0.351-0.524 (0.44
+/-
0.02), Coxa 1 setae = thick tapered, F3 condition = normal/slightly swollen.
Redescription of female exemplar
(APH_0857; Figs 11-13). Specimen preparation and condition: Specimen collected live from burrow, preserved in 80% ethanol; deposited in AUMNH; original coloration faded due to preservation. Left legs I, III, IV, and pedipalp removed for photographs and measurements; stored in vial with specimen. Right leg III removed for DNA and stored at -80°C in the AUMNH (Auburn, AL). Genital plate with spermathecae removed and cleared, stored in vial with specimen. General coloration: Faded black and light brown, medium length, dense setae cover body. Cephalothorax: Carapace 21.37 mm long, 18.26 mm wide; densely clothed with light brown pubescence closely appressed to surface; fringe densely covered in long setae; foveal groove medium deep and straight; pars cephalica region rises from thoracic furrow more steeply than male, gently arching anteriorly toward ocular area; AER procurved, PER strongly recurved; clypeus extends forward on a slight curve; LBl 2.67, LBw 3.35; sternum hirsute, clothed with light black/dark brown, me
dium
length dense setae. Abdomen: Densely clothed dorsally in short black setae with numerous longer, lighter setae interspersed (generally red or orange in situ); dense dorsal patch of black Type I urticating bristles (
Cooke et al. 1972
); ventral side with short, dense black setae. Spermathecae: Paired and separate, possessing dual bulges with the smaller near the interior, with wide bases that are not fused. Legs: Thick and hirsute; densely clothed in a mix of short black/brown pubescence setae. Coxa I: Prolateral surface a mix of fine, hair-like and thick tapered setae. F1 16.02; F1w 4.88; P1 7.53; T1 12.06; M1 9.18; A1 7.54; F3 12.72; F3w 4.56; P3 6.76; T3 9.29; M3 10.09; A3 7.54; F4 16.53; F4w 4.73; P4 7.08; T4 13.31; M4 13.26; A4 8.79. All tarsi fully scopulate. Extent of metatarsal scopulation: leg III (SC3) = 64.4%; leg IV (SC4) = 47.3%. Two ventral spinose setae on metatarsus III; seven ventral spinose setae on metatarsus IV. Pedipalps: Densely clothed in the same setal color as the other legs; one spinose seta on the apical, prolateral femur and five spinose setae on the prolateral tibia.
Variation (13).Cl 16.06-23.8 (20.27
+/-
0.79), Cw 14.9-21.73 (17.951
+/-
0.62), LBl 2.45-3.79 (2.878
+/-
0.1), LBw 2.71-4.3 (3.478
+/-
0.15), F1 13.12-18.14 (15.181
+/-
0.45), F1w 3.87-5.8 (4.945
+/-
0.18), P1 5.61-8.59 (7.196
+/-
0.26), T1 9.76-13.56 (11.616
+/-
0.35), M1 7.0-10.98 (8.911
+/-
0.31), A1 5.73-8.34 (7.138
+/-
0.19), L1 length 42.75-59.3 (50.042
+/-
1.47), F3 10.94-14.63 (12.375
+/-
0.37), F3w 3.36-5.13 (4.268
+/-
0.17), P3
5.1
-7.72 (6.179
+/-
0.23), T3 7.45-10.56 (8.816
+/-
0.28), M3 8.27-12.05 (9.918
+/-
0.34), A3 6.52-8.84 (7.398
+/-
0.18), L3 length 38.67-53.7 (44.687
+/-
1.26), F4 13.27-18.66 (15.654
+/-
0.49), F4w 3.61-5.31 (4.514
+/-
0.17), P4 5.34-8.4 (6.55
+/-
0.28), T4 9.72-13.98 (12.038
+/-
0.35), M4 10.37-16.15 (13.621
+/-
0.46), A4 7.01-9.83 (8.373
+/-
0.25), L4 length 45.86-66.63 (55.723
+/-
1.74), SC3 ratio 0.644-0.763 (0.706
+/-
0.01), SC4 ratio 0.368-0.474 (0.433
+/-
0.01), Coxa 1 setae = thick tapered. Spermathecae variation can be seen in Figures 12-13.
Material examined.
United States: Texas: Bexar: Hollywood Park, 220 Mecca, 29.59413 -98.47946 2, 934ft., [APH_0033, 2/6/2006, 1♂, Connor Shannon, Ryan Tubbesing, AUMNH]; Cameron: 2100 W. San Marcelo Blvd #158, Brownsville, 25.95835 -97.500489 2, 21ft., [APH_0523, 20/5/2009, 1♂, Lilia Perez, AUMNH]; Brownsville, 25.901747 -97.497484 5, 26ft., [APH_2045, 4/1963, 1♀, 1♂, Ted Beimler, AMNH]; Brownsville, field NE Coffeeport Rd, 25.948055 -97.480915 1, 19ft., [APH_0459-0462, 9/4/09, 1♀, 3 juv, Brent E. Hendrixson, AUMNH]; Harlingen, 26.190631 -97.696103 5, 39ft., [APH_2043, 15/11/1939, 1♀, B. Brown, AMNH]; [APH_2044, 1939, 1♀, Bryce Brown, AMNH]; Harlingen, Dixieland Park, 26.16825 -97.72063 1, 43ft., [APH_1273-1275, 12/5/11, 3 juv, Brent E. Hendrixson, Kate Hall, Austin Deskewies, Alexis Guice, AUMNH]; Harlingen, McKelvey Park, 26.180254 -97.679291 1, 35ft., [APH_0463, 9/4/09, 1 juv, Brent E. Hendrixson, AUMNH]; [APH_1271-1272, 11/5/11, 2 juv, Brent E. Hendrixson, Kate Hall, Austin Deskewies, Alexis Guice, AUMNH]; Harlingen, S of town, 26.145617 -97.661717 5, 41ft., [APH_0924, 2006, 1♂, Dave Moellendorf, AUMNH]; Laguna
Vista
, 26.100864 -97.290234 5, 12ft., [AUMS_2355, 4/1998, 1♂, R.G. Breene, AUMNH]; [AUMS_2583, 4/1998, 1♂, R.G. Breene, AUMNH]; [AUMS_2609, 1998, 1♂, R.G. Breene, AUMNH]; [AUMS_2613, unknown, 1♀, R.G. Breene, AUMNH]; [AUMS_2690, 4/1998, 2♂, R.G. Breene, AUMNH]; [AUMS_2695, 4/1998, 1♀, R.G. Breene, AUMNH]; [AUMS_3268-3269, 3/1998, 2♂, R.G. Breene, AUMNH]; [AUMS_3271, 4/1998, 1♂, R.G. Breene, AUMNH]; [AUMS_3274, 4/1998, 1♂, R.G. Breene, AUMNH]; [AUMS_3315, 4/1998, 1♂, R.G. Breene, AUMNH]; Laguna Vista, Roloff Park, 26.10243 -97.291 1, 3ft., [APH_0455-0458, 9/4/09, 2♀, 2 juv, Brent E. Hendrixson, AUMNH]; Los Fresnos, 26.071744 -97.476373 5, 23ft., [AUMS_2688, 1999, 1♀, R.G. Breene, AUMNH]; South Padre Island, 26.076567 -97.16315 5, 4ft., [APH_0858, 2006, 1♀, Dave Moellendorf, AUMNH]; DeWitt: between Cuero and Westhoff on Hwy 87, 29.1221 -97.410817 1, 303ft., [APH_0859-0861, 9/2008, 3♀, Chris A. Hamilton, AUMNH]; [APH_0947, 9/2008, 1♂, Chris A. Hamilton, AUMNH]; Dimmit: 6.7 miles E Maverick County Line on US-277, 28.625443 -100.004038 1, 659ft., [APH_0473, 11/4/2009, 1 juv, Brent E. Hendrixson, AUMNH]; Chaparral Wildlife Management Area, Blocker Pond, 28.3125 -99.40694 1, 570ft., [APH_0025, 12/3/2002, 1♂, Brent E. Hendrixson, WTAMU Herp Class, AUMNH]; 3 miles NW Catarina on US-83, 28.37472 -99.64806 1, 560ft., [APH_0042, 12/3/2000, 1 juv, Brent E. Hendrixson, AUMNH]; Duval: 4.4 miles E Hwy-339 on FM-2295, 27.58835 -98.33743 1, 340ft., [APH_1270, 11/5/11, 1 juv, Brent E. Hendrixson, Kate Hall, Austin Deskewies, Alexis Guice, AUMNH]; 5.3 miles SE Webb County Line on Hwy-44, 27.907752 -98.723635 1, 497ft., [APH_0529, 3/6/09, 1♀, Brent E. Hendrixson, Courtney Dugas, Sloan Click, AUMNH]; S of San Diego, TX on Hwy-359, 27.733177 -98.262366 1, 339ft., [APH_0584, 14/6/2009, 1 juv, Brent E. Hendrixson, Courtney Dugas, Sloan Click, AUMNH]; Fayette: La Grange, 29.914417 -96.866267 1, 330ft., [APH_0804-0806, 5/2008, 3♀, Chris A. Hamilton, AUMNH]; [APH_0808, 5/2008, 1♀, Chris A. Hamilton, AUMNH]; [APH_0809, 5/2008, 1♀, Chris A. Hamilton, AUMNH]; [APH_0898, 5/2008, 1♂, Chris A. Hamilton, AUMNH]; La Grange, S side of river, 29.874417 -96.850383 1, 345ft., [APH_0811, 7/2008, 1♀, Chris A. Hamilton, AUMNH]; [APH_0810, 5/2008, 1♀, Chris A. Hamilton, AUMNH]; [APH_0899, 5/2008, 1♂, Chris A. Hamilton, AUMNH]; [APH_0901, 5/2008, 1♂, Chris A. Hamilton, AUMNH]; La Grange, on FM155, 29.859333 -96.848033 1, 348ft., [APH_0900, 5/2008, 1♂, Chris A. Hamilton, AUMNH]; La Grange, rest stop on Hwy 77, 29.843383 -96.9091 1, 377ft., [APH_0902-0903, 5/2008, 1♀, 1♂, Chris A. Hamilton, AUMNH]; Gonzales: 6.1 miles SE of Gonzales, 29.497194 -97.380048 5, 328ft., [APH_2658, 18/6/1956, 1♂, W. McAlister, AMNH]; Harris: Houston, 29.760193 -95.36939 6, 43ft., [APH_2650, 6/1959, 1♂, Mrs. Emilie Steude, AMNH]; Jim Hogg: 0.9 miles E Zapata County Line on FM-2687, 26.939665 -98.941918 1, 526ft., [APH_1131, 15/3/2010, 1 juv, Brent E. Hendrixson, Gerri Wilson, Thomas Martin, AUMNH]; 2.0 miles N Starr County Line on FM-649, 26.81392 -98.855998 1, 625ft., [APH_1130, 15/3/2010, 1 juv, Brent E. Hendrixson, Gerri Wilson, Thomas Martin, AUMNH]; Karnes: Karnes City, 28.885483 -97.902683 1, 411ft.,
[
APH_0864-0866, 9/2008, 2♀, 1 juv, Chris A. Hamilton, AUMNH]; [APH_0952, 9/2008, 1♂, Chris A. Hamilton, AUMNH]; Kleberg: Kingsville, S Brahma Blvd, 27.4806 -97.855767 1, 77ft., [APH_0856-0857, 9/2008, 2♀, Chris A. Hamilton, AUMNH]; Kingsville, 27.515869 -97.856109 5, 56ft., [APH_2046, 27/6/1970, 1♂, Gillaspy, AMNH]; Kingsville, field at high school, along Caesar Ave across street from cemetery, 27.506531 -97.879785 1, 65ft., [APH_0579-0583, 13/6/2009, 4 juv, Brent E. Hendrixson, Courtney Dugas, Sloan Click, AUMNH]; La Salle: Cotulla, 28.436934 -99.235032 1, 437ft., [APH_3129, 2013, 1♂, Roger Birkhead, AUMNH]; Los Angeles, 28.460017 -98.9999 1, 391ft., [APH_0871, 2008, 1♀, Sky Stevens, AUMNH]; Maverick: 4.2 miles SW Zavala County Line on Hwy-57, 28.88947 -100.16539 2, 711ft., [APH_1458, 24/1/2012, 1 juv, Stanley A. Schultz, AUMNH]; 4.6 miles E/SE Eagle Pass (jct US-57) on US-277, 28.69567 -100.39303 1, 833ft., [APH_0055, 17/7/2006, 1♂, Brent E. Hendrixson, AUMNH]; [APH_0058, 17/7/2006, 1♀, Brent E. Hendrixson, AUMNH]; [APH_0084, 17/7/2006, 1♀, Brent E. Hendrixson, AUMNH]; 9.0 miles NE US-57 on FM-481, 28.928198 -100.262798 1, 787ft., [APH_1149-1150, 17/3/2010, 2 juv, Brent E. Hendrixson, Gerri Wilson, Thomas Martin, AUMNH]; McMullen: 1.25 miles N FM-3445 on TX-16, 28.520536 -98.547662 1, 300ft., [APH_1117, 14/3/2010, 1 juv, Brent E. Hendrixson, Gerri Wilson, Thomas Martin, AUMNH]; Nueces: Corpus Christi, Meldo Park, approx. 2 blocks SW Santa Fe St on Brawner Parkway, 27.747437 -97.379802 1, 41ft., [APH_0577-0578, 13/6/2009, 2 juv, Brent E. Hendrixson, Courtney Dugas, Sloan Click, AUMNH]; Starr: San Carlos, Hwy 649 ~ 2 miles N of 2686 junction, 26.720783 -98.8468 1, 411ft., [APH_0889, 18/4/2008, 1♀, Christian Cox, Corey Roelke, AUMNH]; Washington: 2301 Running Valley Lane, Washington, 30.225692 -96.160138 1, 224ft., [APH_3123, 13/6/2013, 1♂, Chuck Matula, AUMNH]; 5 miles west of Carmine, 30.140828 -96.759342 5, 433ft., [APH_2660, 27/6/1960, 2♀, W. McAlister, AMNH]; Brenham, 30.145467 -96.43435 5, 323ft., [APH_0968, 6/2006, 1♂, Dave Moellendorf, AUMNH]; Chappell Hill, 1/4 mile S of intersection of Old Chappell Hill Rd and Pulaski School Rd, 30.1577 -96.288344 1, 282ft., [APH_3121, 20/5/2013, 1♂, Todd Burch, AUMNH]; [APH_3122, 30/5/2013, 1♂, Todd Burch, AUMNH]; Webb: 0.8 miles NW Hwy-44 on US-83, 28.03711 -99.54681 1, 820ft., [APH_1285, 13/5/2011, 1♂, Brent E. Hendrixson, Kate Hall, Austin Deskewies, Alexis Guice, AUMNH]; 1.1 miles SW Duval County Line on US-59, 27.786023 -98.818769 1, 451ft., [APH_0524-0528, 3/6/09, 3♀, 2 juv, Brent E. Hendrixson, Courtney Dugas, Sloan Click, AUMNH]; 3.2 miles W FM-2895 on TX-359, 27.454855 -99.136257 1, 511ft., [APH_1125, 15/3/2010, 1 juv, Brent E. Hendrixson, Gerri Wilson, Thomas Martin, AUMNH]; 3.6 miles NW I-35 on US-83, 27.80051 -99.46291 1, 760ft., [APH_1281-1282, 13/5/2011, 2 juv, Brent E. Hendrixson, Kate Hall, Austin Deskewies, Alexis Guice, AUMNH]; 4.3 miles E Loop-20 on US-59 at Los Tios Creek, 27.56159 -99.39045 1, 470ft., [APH_1280, 13/5/2011, 1 juv, Brent E. Hendrixson, Kate Hall, Austin Deskewies, Alexis Guice, AUMNH]; 5.1 miles SE La Salle County Line on Hwy-44, 28.012456 -99.195109 1, 454ft., [APH_0530-0531, 3/6/2009, 2 juv, Brent E. Hendrixson,
Courtney
Dugas, Sloan Click, AUMNH]; Wharton: El Campo, 29.19405 -96.2617 1, 90ft., [APH_0800-0803, 7/2008, 4♀, Chris A. Hamilton, AUMNH]; Zapata: 2.0 miles NW FM-2687 on US-83, 26.80362 -99.142 1, 410ft., [APH_1277-1279, 13/5/2011, 1♂, 2 juv, Brent E. Hendrixson, Kate Hall, Austin Deskewies, Alexis Guice, AUMNH]; Mexico: Nuevo Leon:
Canon
de la Huasteca, 25.61484 -100.47585 1, 2600ft., [APH_0056, 24/7/2006, 1♀, Brent E. Hendrixson, AUMNH].
Distribution and natural history.
In the United States,
Aphonopelma anax
is widely distributed throughout South Texas (Fig. 14). We only sampled a single individual from western Nuevo Leon but the species distribution model predicts suitable habitat for
this
species throughout northeastern Mexico in Coahuila, Nuevo Leon, and Tamaulipas. The vast majority of specimens were collected at elevations between sea level and 300 meters along the Western Gulf Coastal Plain (Fig. 1I) or Southern Texas Plains Level III Ecoregions, but other samples were obtained from the Texas Blackland Prairies, East Central Texas Plains, South Central Plains, and the very southern edge of the Edwards Plateau. The specimen from Nuevo Leon (at Huasteca Canyon near Monterrey) was collected at an elevation of approximately 850 meters. This species has been observed in syntopy with
Aphonopelma moderatum
(burrows located fewer than 50 centimeters from each other) at several different locations near the Rio Grande from Eagle Pass (Maverick County) to Rio Grande City (Starr County).
Aphonopelma anax
may also be found alongside
Aphonopelma armada
and
Aphonopelma hentzi
. Burrows are typical of that for North American tarantulas (i.e., circular and generally covered by a thin veil of silk) and specimens can be readily collected by pouring a small amount of water into their burrows. In extreme South Texas,
Aphonopelma anax
is probably active year-round; however, in more northern populations, spiders likely plug their burrows for short periods of time during the winter. The breeding period appears to be restricted to spring and early summer (April-July); adult males have been observed in large numbers at night along roads following heavy bouts of rain (United States Border Patrol 2009, pers. comm.).
Figure 14.
Aphonopelma anax
(Chamberlin, 1940). A distribution of known specimens B predicted distribution; warmer colors (red, orange, yellow) represent areas of high probability of occurrence, cooler colors (blue shades) represent areas of low probability of occurrence.
Conservation status.
Aphonopelma anax
is very common throughout its distribution. Extensive fieldwork near Edinburg and McAllen (Hidalgo County) suggests that some local populations of
Aphonopelma anax
have probably been extirpated due to extensive agriculture in the Lower Rio Grande Valley, but overall the species is fairly abundant throughout South Texas. These spiders appear to thrive in a variety of anthropogenic settings including golf courses, residential lawns, city parks, roadside picnic areas, and mowed highway shoulders. The status of
Aphonopelma anax
is likely secure.
Remarks.
Aphonopelma anax
is one of the largest and most robust
Aphonopelma
within the United States. This species exhibits size variation within males and females across their distribution, with northern populations generally smaller and the southern populations representing the largest tarantulas in the United States. Other important ratios that distinguish males:
Aphonopelma anax
possess a smaller M1/F4 (≤0.75; 0.69-0.75) than
Aphonopelma moderatum
(≥0.80; 0.80-0.88) and
Aphonopelma moellendorfi
(≥0.81; 0.81-0.88). No other ratios distinguish female
Aphonopelma anax
from their syntopic or closely related phylogenetic species. For both males and females, certain morphometrics have potential to be useful though due to the amounts of variation, small number of specimens, and the small differences between species none are claimed to be significant at this time (see Suppl. material 2). During evaluation of traditional PCA morphospace, males of
Aphonopelma anax
separate from
Aphonopelma moderatum
,
Aphonopelma moellendorfi
, and
Aphonopelma gabeli
along PC1~2, but do not separate from
Aphonopelma armada
or
Aphonopelma hentzi
. Females separate from
moderatum
along PC1~2, but do not separate from
Aphonopelma armada
,
Aphonopelma gabeli
,
Aphonopelma hentzi
. Females of
Aphonopelma moellendorfi
are unknown at this time and cannot be compared. Interestingly,
Aphonopelma anax
males separate from
Aphonopelma gabeli
,
Aphonopelma moderatum
, and
Aphonopelma moellendorfi
in three-dimensional PCA morphospace (PC1~PC2~PC3), but do not separate from
Aphonopelma armada
and
Aphonopelma hentzi
.
Aphonopelma anax
females separate from
Aphonopelma armada
and
Aphonopelma
moderatum
, but do not separate from
Aphonopelma gabeli
and
Aphonopelma hentzi
. PC1, PC2, and PC3 explain ≥87% of the variation in male analyses and ≥96% of the variation in female analyses.
It is important to note the tremendous amount of variation that can be observed in the shape of the spermathecae from numerous populations of
Aphonopelma anax
(Figs 12-13). Previous taxonomic work considered this amount of variation to represent differences between species (e.g.,
Smith 1995
differentiated his new species
Aphonopelma breenei
from
Aphonopelma anax
on the basis of its spermathecae) (
Smith 1995
) but our samples demonstrate that the shape of spermathecae is quite variable and is not useful for differentiating these two species. The spermathecae are however useful for distinguishing
Aphonopelma anax
from other members of the
Hentzi
species complex (
Aphonopelma armada
and
Aphonopelma hentzi
). This information was used to place
Aphonopelma harlingenum
(whose type locality is surrounded by
Aphonopelma anax
) into synonymy with
Aphonopelma hentzi
and not
Aphonopelma anax
. It is also important to note that the paratype of
Aphonopelma harlingenum
that is found in the same jar as the
Aphonopelma harlingenum
holotype is a female of
Aphonopelma anax
(see spermathecae in Fig. 12C). Additionally, as seen in the spermathecae, we find that palpal bulb variation is extreme both across and within
Aphonopelma
species - an unfortunate finding that further enforces our idea that these traditionally used morphological characters are ineffective species delimiters. Unless these characters are extreme autapomorphies (i.e.
Aphonopelma anax
spermathcae and palpal bulbs,
Aphonopelma gabeli
spermathecae) that can be used in conjunction with other evidence to determine species boundaries in this group of spider, they should not be regarded as taxonomically informative.
Mitochondrial DNA (CO1) identifies
Aphonopelma anax
as a polyphyletic group with respect to
Aphonopelma armada
and
Aphonopelma hentzi
(Fig. 7). A second lineage of
Aphonopelma anax
is sister to a lineage of
Aphonopelma hentzi
; both of these lineages were previously identified as putative cryptic species (
Hamilton et al. 2014
). The AE data demonstrate that CO1 is not effective at accurately delimiting species boundaries within this group. Finally, we examined the holotype and freshly collected topotypic material of
Aphonopelma breenei
. Our morphological and molecular analyses fail to recognize this species as a separate, independently evolving lineage. As a consequence, we consider
Aphonopelma breenei
a junior synonym of
Aphonopelma anax
.