Corresponding author: Joel Ledford (
Academic editor: J. Miller
The spider genus
While
Recent studies on
Several geological areas are recognized on the Edward’s Plateau, however most of the subterranean diversity is known from caves along the heavily faulted Balcones Escarpment (
This study revises the taxonomy of
A resurgence of interest in Texas cave biology, driven largely by conservation efforts, has produced a wealth of new
Voucher specimens for the study are deposited at the California Academy of Sciences (CASC), the Texas Memorial Museum (TMM), the Museum of Texas Tech University (TTU) and the Essig Museum, University of California, Berkeley (UCB).
Due to the sensitive nature of cave locations and in the spirit of respecting the rights of property owners and encouraging future research, precise locality information is not provided. Unless otherwise noted, all cave locations are limited to within 2 kilometers. Specimens used in this study along with their voucher codes are listed in
Distribution maps were produced using Arc GIS 10.0 (Environmental Systems Research Institute, CA). Karst faunal region boundaries were derived from shape files provided by Zara Environmental (K. O’Connor) through the U.S. Fish and Wildlife Service.
Prior to examination with a Leo 1450VP Scanning Electron Microscope, all structures were cleaned with a fine brush or ultrasonicator and critical point dried. Best results were obtained by gradually dehydrating the specimen in increasing concentrations of ethanol for 24-48 hours prior to critical point drying. Dried specimens were then mounted on pin mount SEM stubs (Ted Pella Inc., Redding, USA) on copper-backed tape. Specimens were sputter coated for 120 seconds using a Denton Vacuum Sputter Coater. Large structures were photographed using a Nikon DMX1200 camera attached to a Leica MZ 16 stereomicroscope. Images were then montaged using Helicon Focus v. 4.2.1 (
Vulvae were carefully excised and placed in a pancreatin solution for 24-48 hours to digest extraneous tissue (
Descriptions follow the format of
List of Anatomical Abbreviations used in the text and figures.
|
|
---|---|
AER | Anterior Eye Row |
AME | Anterior Median Eyes |
At | Atrium |
E | Embolus |
PME | Posterior Median Eyes |
RS | Retrolateral Sclerite |
RTS | Retrolateral Tibial Sclerite |
SH | Spermathecal Head |
SS | Spermathecal Stalk |
TS | Palpal Tarsus |
VS | Ventral Sclerite |
Detailed protocols for the extraction, amplification and sequencing of DNA are reported in
Bayesian analysis was performed using MrBayes v. 3.1.2 (
Aligned data matrices and trees will be made available online in TreeBASE (
Summary tree statistics and conditions for each analysis.
|
|
|
|
---|---|---|---|
Concatenated | Parsimony, PAUP* v.4b10 | 1000 iterations, heuristic search with TBR | 130 trees, 8124 steps |
COI (full partitions) | Likelihood, RAxML v.7.0.4 | 1000 non-parametric bootstrap replicates | -lnL 16062.90 |
Histone 3 (full partitions) | -lnL 2910.70 | ||
28s rDNA | -lnL 20318.74 | ||
Three-gene concatenated | -lnL 34742.79 | ||
Two-gene concatenated (COI, 28s) | -lnL 34550.09 | ||
COI (full partitions) | Bayesian, Mr. Bayes v.3.1.2 | 20,000,000 generations, burnin= 25% | sdsf 0.003 |
COI (1st and 2nd, 3rd positions) | sdsf 0.003 | ||
COI (unpartitioned) | sdsf 0.003 | ||
Histone 3 (full partitions) | sdsf 0.004 | ||
Histone 3 (1st and 2nd, 3rd positions) | sdsf 0.01 | ||
Histone 3 (unpartitioned) | sdsf 0.03 | ||
28s rDNA | sdsf 0.008 | ||
Three-gene concatenated | 50,000,000 gen, burnin= 25% | sdsf 0.05 | |
Two-gene concatenated (COI, 28s) | 20,000,000 gen, burnin= 25% | sdsf 0.01 |
Primer sequences, source and annealing temperatures. Optimized annealing temperatures in bold.
|
|
|
|
|
|
|
|
---|---|---|---|---|---|---|---|
COI | 1718 | 5-ggA ggA TTT ggA AAT TgA TTA gTT CC-3 |
|
2568 | 5-gCT ACA ACA TAA TAA gTA TCA Tg-3 |
|
44-50, |
COI | 1751 | 5 -gAg CTC CTg ATA TAg CTT TTC C-3 |
|
2568 | 5-gCT ACA ACA TAA TAA gTA TCA Tg-3 |
|
44-50, |
COI | PMT1 | 5-GGT CAA CAA ATC ATA AAG ATA TTG G-3 |
|
2568 | 5-gCT ACA ACA TAA TAA gTA TCA Tg-3 |
|
44-50, |
COI | 1490-ONO | 5-CW ACA AAY CAT ARR GAT ATT GG-3 |
|
2568 | 5-gCT ACA ACA TAA TAA gTA TCA Tg-3 |
|
44-50, |
COI | 2309 | 5-TTT ATg CTA TAg TTg gAA TTg g-3 |
|
2776 | 5-ggA TAA TCA gAA TAN CgN CgA gg-3 |
|
44-50, |
28srDNA | ZX1 | 5-ACC CGC TGA ATT TAA GCA TAT-3 |
|
ZR2 | 5-CCG AAG TTT CCC TCA GGA TAG C-3 |
|
50-60, |
28srDNA | 28sOCS | 5-CGT GAA ACT GCT CAG AGG-3 |
|
28sC | 5-GGC GAA AGA CTA ATC GAA CC-3 |
|
50-60, |
Histone 3 | H3af | 5-ATG GCT CGT ACC AAG CAG ACV GC-3 |
|
H3ar | 5-ATA TCC TTR GGC ATR ATR GTG AC-3 |
|
48-55, |
Histone 3 | H3nf | 5-ATG GCT CGT ACC AAG CAG AC-3 |
|
H3nr | 5-ATR TCC TTG GGC ATG ATT GTT AC-3 |
|
48-55, |
Exemplars for each
Putativesynapomorphies for
In contrast to other leptonetine genera, the palpal morphology of
The ventral sclerite (VS) is a single, spine-like projection that extends approximately half the length of the embolus. The position and length of the VS ranges from elongate and mesal as in
The retrolateral tibial spine (RTS) is recurved to straight and ranges from short, occupying less than half the length of the palpal tarsus (RTS,
Examination of female genitalia using compound microscopy revealed relatively little variation among species and in most cases female specimens appear nearly identical in structural details (
Results of phylogenetic analyses follow
Tree topologies are identical to
Four clades recovered by analyses are identified as species-groups in the discussion: 1) the
Among the most interesting results of the phylogenetic analyses is the contrast in branch lengths between
Although most
Biogeographic relationships within
The majority of species described by
Karst faunal regions (KFR’s) were originally developed as tools to aid the recovery of endangered karst invertebrates by identifying geologically independent regions that had a relatively high proportion of endemic species (Veni, 1992, 1994). Although an evolutionary model was not explicitly proposed, the inherent reasoning is that the present distribution of the karst invertebrate fauna can be explained by the fragmented geology of the region (
While the distribution of
Following the arguments of
The key presented here relies heavily on fine details of the male and female genitalia, some features of which are not visible using conventional light microscopy or without special preparation techniques. Scanning electron and compound light microscopy is essential for positive identification and the females of most species are not diagnosable in the absence of associated males.
1 | Male palpal tarsus tapering apically, rarely with weak division ( |
2 |
– | Male palpal tarsus with strong apical division ( |
15 |
2 | Bulb bearing a prominent ventral sclerite (VS, |
3 |
– | Bulb lacking a ventral sclerite ( |
9 |
3 | Ventral sclerite elongate (VS, |
4 |
– | Ventral sclerite elongate; embolus shape irregular, with sculpture, bifurcation, or large basal tooth along margin (E, |
6 |
4 | Ventral sclerite short, occupying less than the width of the embolus (VS, |
|
– | Ventral sclerite elongate, occupying at least 0.50× length of apical portion of bulb (VS, |
5 |
5 | Base of embolus sharply curved, projecting ventrally ( |
|
Notes. |
||
– | Base of embolus weakly curved, projecting anteriorly, often with an apical cleft (E, |
|
6 | Depigmented, blind spiders (faint eyespots may be present under high magnification); length femur I at least 1.90× carapace length; retrolateral tibial spine short to elongate; embolus narrowly or broadly bifurcate, with or without large basal tooth | 7 |
– | Pigmented, large-eyed spiders with dark patterns surrounding the ocular area; length femur I 1.0–1.5× carapace length; retrolateral tibial spine short, occupying less than 0.5× length of palpal tarsus; embolus broad, with prominent basal tooth | |
7 | Embolus bifurcate, with sharp lobes (E, |
8 |
– | Embolus bifurcate, with rounded lobes (E, |
|
8 | Embolus broad, with distinct basal tooth (E, |
|
– | Embolus narrow, bifurcate (E, |
|
Dist. Known from three caves in the Onion Creek watershed of Barton Springs, Travis County, Texas ( |
||
9 | Embolus rounded to rectangular, lacking basal tooth and with minimal sculpture along margins (E, |
10 |
– | Embolus rounded to rectangular, with prominent basal tooth (E, |
13 |
10 | Embolus oval or tapering apically (E, |
11 |
– | Embolus rectangular to gently curved along its base, flush with apical portion of bulb; retrolateral tibial spine short to elongate | 12 |
11 | Eyes reduced, lacking pigmentation near ocular area ( |
|
– | Eyes large and darkly pigmented near ocular area ( |
|
12 | Embolus rectangular, folded apically (E, |
|
– | Embolus rectangular and gently curved along its base (E, |
|
13 | Eyes and pigmentation variable, greatly reduced in one species ( |
14 |
– | Eyes large and darkly pigmented near ocular area ( |
|
14 | Eyes and pigment greatly reduced, only faint eyespots present ( |
|
– | Eyes and pigment normal, with dark marking surrounding ocular area ( |
|
15 | Embolus with distinctive basal tooth, shape rectangular to bifurcate (E, |
16 |
– | Embolus smooth along margins, shape oval to subquadrate, with weakly developed basal swelling or absent (E, |
17 |
16 | Eyes and pigment greatly reduced ( |
|
– | Eyes and pigment variable ( |
|
17 | Embolus oval, with or without apical fold (E, |
18 |
– | Embolus rectangular, tapering apically, with weak basal swelling (E, |
|
18 | Eyes and pigment reduced ( |
|
– | Eyes and pigment normal ( |
Images of habitat and cave entrances for
Live images of
Map of the study area, with an inset highlighting the distribution of
Three gene concatenated Bayesian phylogeny from
Three gene concatenated maximum likelihood phylogeny from
Three gene concatenated parsimony phylogeny from
Bayesian gene tree, cytochrome oxidase I (COI) from
Bayesian gene tree, histone 3 (H3) from
Bayesian gene tree, 28s rDNA (28s) from
General morphology of
Spinneret morphology for male
Species of
Total length 1.0-1.98. Carapace depigmented to orange-brown; oval and covered by fine, irregular sculpturing which refracts light producing a distinctive iridescence (
Nineteen species, ten of which are described in this paper:
Central to West Texas (
Female holotype from Cobb Cave (= Cobb’s Caverns), 15 miles north of Georgetown, Williamson County, Texas, 31-March-1963, J. Reddell, D. McKenzie,
Cobb Cave is also known as Cobb’s Caverns and is located on the Cobb Ranch in Northern Williamson County (
Complete description of female in
Known only from two caves in Williamson County, Texas (
An egg-sac for this species was found with a female specimen from Corn Cobb’s Cave (
Male holotype from Grapevine Cave, 7 miles west of Wimberly, Hays County, Texas, 18-Nov-2009, J. Ledford, K. O’Connor,
This species is named in honor of Martin Archambault, fellow caver and friend who helped collect many leptonetids in Texas and Mexico.
This species is known only from Burnett Ranch Cave and Grapevine Cave in southwestern Hays County (
Individuals for this species were collected throughout Grapevine Cave, however, most specimens were encountered at the base of the cave’s vertical entrance in the twilight area under stones. They were collected in fine sheet webs similar to other
Male holotype from Up the Creek Cave, Camp Bullis, Bexar County, Texas, 10-September-1998, J. Cokendolpher, J. Reddell, J. Krejca, M. Reyes,
Two female specimens from Hills and Dale’s Pit are tentatively assigned to this species based on the similarity of the female genitalia and by having identical COI and 28s rDNA sequences to specimens collected in Up the Creek Cave.
Complete description in
Known from two caves in Bexar County, Up the Creek Cave on Camp Bullis and Hills and Dale’s Pit (
Male holotype from Heidrich’s Cave, New Braunfels, 20-June-1938, Comal County, Texas, 20-June-1938,
Heidrich’s Cave was the name used by
Complete description in
Caves and surface localities in Hays and Comal Counties (
Male holotype from Lost Gold Cave, 13 miles SW of Austin, Travis County, Texas, 27-May-1963, J. Reddell and B. Frank,
Complete description in
Known from three caves in Travis County, Texas (
Individuals collected in Stark’s North Mine were found in small sheet webs at the base of chalk walls, rotting wood and breakdown material.
Female holotype from Shultz Cave, 2mi. E. of Volente, Travis County, Texas, 21-August-1963, B. Russell,
Shultz Cave is commonly referred to as MacDonald Cave and is located approximately 2.5mi. NE of Volente in Travis County. Although the male for this species was not available to
Complete description of female in
Known from caves and surface localities in Travis and Williamson Counties, Texas (
Male holotype and female from Emerald Sink, Val Verde County, Texas, 3-November-1984, J. Reddell, M. Reyes,
The species name is taken in apposition to the type locality.
Known only from Emerald Sink, Val Verde County, Texas (
Male holotype from Fawcett’s Cave, Devil’s River State Natural Area, Val Verde County, Texas, 10-November-2009, J. Ledford, J. Kennedy, M. Sanders, T. Garot, K. Wardlaw,
The species name is taken in apposition to the type locality and honors the Fawcett family, who owned Fawcett’s Cave and the surrounding Fawcett Ranch prior to its transition as a State Natural Area in 1988.
Specimens from Fawcett’s Cave were originally considered by
Known only from Fawcett’s Cave in the Devil’s River State Natural Area, Val Verde County, Texas (
Individuals of
Male holotype from Litterbarrel Cave, 5mi. southeast of Comstock, Val Verde County, Texas, 1-September-1974, S. Sweet, M. Reaka,
This species is named in honor of Andy Grubbs, a remarkable collector of several new
The coloration of this specimen has likely been affected by its preservation conditions.
Known only from Litterbarrel Cave, Val Verde County, Texas (
Male holotype from Madla’s Cave, Bexar County, Texas, 18-December-2003, K. White,
This species name is taken in apposition to the type locality and honors the Madla family, owners of Madla’s Cave and the surrounding property.
Although the majority of records for this species are from caves, a small series of individuals have been collected from leaf litter near the entrance to Madla’s Cave that are genetically identical to specimens within the cave. The somatic morphology of the species (large, darkly pigmented eyes;
Eyes large, ocular area enclosed in a dark pattern (
Known only from Madla’s Cave in Bexar County, Texas (
Female holotype from Government Canyon Bat Cave, 5 miles SW Helotes, Bexar County, Texas, 11-August-1965, J. Reddell, J. Fish (AMNH, examined).
Complete description of female in
One adult male specimen was collected for DNA extraction and scanning electron microscopy in November 2009. Although only a single male was found, immature and female specimens were commonly observed in small sheet webs under breakdown material and at the base of walls on opposite sides of the cave entrance.
Known only from Government Canyon Bat Cave, Bexar County, Texas (
Male holotype from Tooth Cave, Travis County, Texas, 30-March-1965, J. Reddell,
Complete description in
Known from caves in Travis and Williamson Counties, Texas (
Individuals in Geode Cave and Tooth Cave were observed suspended beneath sheet webs at the bases of stable rocks and breakdown material (
Male holotype from Fern Cave, Hays County, Texas, 26-May-1989, A. Grubbs, J. Reddell, M. Reyes,
This species is named in honor of Kathleen O’ Connor, fellow caver and biologist who helped collect many exciting
A single adult male collected from Cathy’s Cave, Hays County, Texas shares the genitalic morphology of
Known only from two caves in Hays County, Texas (
Male holotype from Peep in the Deep Cave, Fort Hood, Bell County, Texas, 8-May-1998, J. Reddell, M. Reyes,
Complete description in Cokendolpher (2001: 46). Habitus of male and female in
Caves of Fort Hood, Bell County, Texas and surface localities in Blanco, Burnett, Travis and Williamson Counties, Texas (
Female holotype from District Park Cave, Travis County, Texas, 19-November-2009, J. Ledford, M. Sanders,
This species is named in honor of Mark Sanders, fellow caver, biologist, and collector of several
The only known adult male for
Three individuals were found deep in District Park Cave in fine sheet webs under loose rocks. The single male individual was found wandering among loose rocks in Whirlpool Cave.
Known from three caves in Travis County, Texas (
Male holotype from Constant Sorrow Cave, Camp Bullis, Bexar County, Texas, 6-March-2001, G. Veni,
This species is named in honor of Peter Sprouse, fellow caver, biologist and collector of several
Known from two caves in Bexar County, Texas (
Male holotype from Oriente Milestone Molasses Bat Cave, 20 miles NE of Del Rio, Val Verde County, Texas, 25-January-1964, J. Reddell, McKenzie, Porter,
Complete description in
Known from caves and surface localities in Bandera, Uvalde and Val Verde Counties, Texas (
Male holotype from 400 Foot Cave, Glass Mountains, Brewster County, Texas,
This species name is derived from the Spanish name for the Glass Mountains “Sierra del Vidrio” in West Texas. The name is to be treated as a noun in apposition.
Known only from 400 foot Cave, Brewster County, Texas (
Male holotype from Lithic Ridge Cave, Government Canyon State Natural Area, Bexar County, Texas, 6-November-2002, Engelhard, J. Krejca,
This species is named in honor of Kemble White, fellow caver, geologist and collector of many
Several individuals of
Known from caves in Bexar and Medina Counties, Texas (
Morphology of
General morphology of
Female genitalia for
Female genitalia for
Female genitalia for
Distribution map showing morphotypes within
Distribution map for
Distribution map for
Distribution map for
Distribution map for
Distribution map for
Distribution map for undetermined
Distribution of
Distribution of
We thank the members of the Evolab at U.C. Berkeley, Griswold lab, California Academy of Sciences, Hedin lab, San Diego State University and the Susan Masta lab, Portland State University. George Roderick and Rosemary Gillespie provided invaluable support and guidance. Norman Platnick, Darrell Ubick and Jeremy Miller provided many helpful discussions about leptonetid spiders. Peter Sprouse, Jean Krejca and Mark Sanders provided photos of leptonetids, cave coordinates and helpful discussions about cave biology. Anthea Carmichael, Sarah Crews and Sean Schoville provided invaluable assistance in the lab. Jeremy Brown and the Bodega Phylogenetics Workshop provided instruction on phylogenetic methods. Giovanni Maki provided help with the figures and Tamas Szuts provided help with imaging. Mark Sanders, Kathleen O’ Connor, James Reddell and Peter Sprouse provided specimens and help in the field. The amazing Jim “Crash” Kennedy and Kerr Wardlaw facilitated access to Fawcett’s Cave at the Devil’s River State Natural Area. Permits were kindly facilitated through Cyndee Watson, U.S. Fish and Wildlife Service, David Riskind, Texas Parks and Wildlife, Kimble White, SWCA Environmental Consultants and Kathleen O’Connor, Zara Environmental. This study was supported by a National Science Foundation Doctoral Dissertation Improvement Grant (DDIG-0909872), the Exline-Frizzell fund at the California Academy of Sciences, the Walker Fund at U.C. Berkeley, the National Speleological Society (NSS general research grant) and the University of California. A draft of this manuscript was critically reviewed by Jeremy Miller and Darrell Ubick. Constructive feedback from Mark Harvey and Norman Platnick helped improve the manuscript.