A new trapdoor spider species from the southern Coast Ranges of California (Mygalomorphae, Antrodiaetidae, Aliatypus coylei, sp. nov,), including consideration of mitochondrial phylogeographic structuring
Author
Hedin, Marshal
Author
Carlson, Dave
text
Zootaxa
2011
2963
55
68
journal article
10.5281/zenodo.201647
273a0d8d-e7a3-4f10-a202-06f60a756251
1175-5326
201647
Aliatypus coylei
new species
Figs 1–5
Type
material.
Male
holotype
from Arroyo Seco Gorge, W of Arroyo Center, Monterey County, California,
36.2332°N
,
121.4921°W
, collected
12 October 2003
, M. Hedin & J. Starrett (MY999, CASENT9039430).
COI
GenBank
JN034076
, MorphBank images 588043-47. Female
paratype
from Carmel Valley Road,
1.25 km
N of intersection with Tassajara Road, Monterey County, California,
36.4068°N
,
121.5918°W
, collected
25 November 2003
, J. Starrett (MY1013, CASENT9039431).
COI
GenBank
JN034075
, MorphBank images 588033-34.
Etymology.
Patronym honoring mentor and friend Dr. Fred Coyle, in recognition of his rigorous and inspirational systematic research conducted on mygalomorph spiders, including the genus
Aliatypus
.
Diagnosis
(
Figs 2–4
). Males are distinguished from those of other
Aliatypus
species by the following combination of characters—sternum like
A. thompsoni
Coyle
and species of the
A. erebus
group, with relatively large, relatively closely-spaced posterior sternal sigilla (
Coyle 1974, figs 60–64
). This shape is best captured by the CL/PSL and SW/PSS ratios (
Table 2
). The shape of the
A. coylei
palpal tibia (banana-shaped) is unlike the above species, except for
A. torridus
(
Coyle 1974, fig. 91
). This shape is best captured by the PTX/PTL ratio (
Table 2
). Leg I segments of
A. coylei
males are relatively longer than
A. torridus
males (CL/IFL ratio,
Table 2
).
Females are distinguished from those of other
Aliatypus
species by the following combination of characterssternum most like species of the
A. erebus
group, with relatively large posterior sternal sigilla (
Coyle 1974, figs 74–77
), but not as closely spaced as those of
A. thompsoni
(see PSL/PSS ratio,
Table 2
).
Aliatypus coylei
also differs from
A. thompsoni
in having few ensiform macrosetae on metatarsus I, in possessing a thoracic pit, and in the shape of the seminal receptacles. Females of
A. coylei
are relatively short-legged, again like members of the
A. erebus
group (e.g., CL/IVTL ratio,
Table 2
), and possess similar-shaped seminal receptacles (
Coyle 1974, figs 174– 194
). Of the species in the
A. erebus
group,
A. erebus
and
A. torridus
are most likely to be confused with
A. coylei
(
A. trophonius
Coyle
is diminutive, and
A. plutonis
Coyle
is known only from far southern California). Although CL/PSL and SW/PSL ratios may be useful in distinguishing
A. coylei
from
A. erebus
and
A. torridus
(see
Table 2
), these morphological characters are unlikely to be strictly diagnostic. If genomic resources are available, the following amino acid changes in the COI reference alignment can be used to separate
A. coylei
from all members of the
A. erebus
group: position 15 (Phe in
A. coylei
, Ser
in
A. erebus
group members), position 17 (Val, Glu), position 153 (Ile, Val), position 294 (Tyr, Asn), and position 310 (Cys, Asn).
TABLE 2.
Comparison of informative character ratios in
Aliatypus
.
Females CL/IVTL CL/PSS CL/PSL SW/PSS SW/PSL PSL/PSS
A. californicus
group 2.3–2.9 4.7–8.3 12.1–33.2 2.6–4.4 6.5–16.2 0.2–0.7
A. aquilonius
2.5–2.8 4.4–6.8 17.5–41 2.3–3.4 8.8–20 0.1–0.4
A. gulosus
2.9–3.3 4.8–6.3 13.5–22.2 2.6–3.4 7.1–13.7 0.2–0.4
A. thompsoni
2.6–3.1 12.7–31.6 6.5–10.9 6.6–18.4 3.3–5.7 1.3–4.1
A. erebus
3.0–3.5 7.7–14.7 6.5–9.8 4.3–8.5 3.8–5.3 0.8–2.0
A. torridus
3.1–3.4 8–10 8.3–10 4.4–5.4 4.6–5.4 0.8–1.1
A. coylei
3.1 9.3 10.8 4.9 5.7 0.9
Notes.
Male and female data for species other than
A. coylei
are from Tables 1 & 2 of
Coyle (1974)
. All measurements in millimeters.
Males CL/IFL |
CL/PPL |
PTT/PTL |
PTX/PTL |
CL/PSL |
SW/PSS |
A. californicus
group 0.9–1.2
|
1.3–1.9 |
0.2–0.3 |
0.7–0.8 |
13.6–24.4 |
2.2–4.3 |
A. aquilonius
0.9–1
|
1.3–1.4 |
0.2 |
0.7 |
24.3–34.1 |
2.2–2.5 |
A. gulosus
0.9–1
|
1.3–1.5 |
0.2 |
0.4–0.5 |
22.1–30.7 |
2.2–2.9 |
A. thompsoni
0.8–0.9
|
1.3–1.6 |
0.2–0.3 |
0.7–0.8 |
8–10.7 |
5.9–12.5 |
A. erebus
1.2–1.3
|
1.6–2.0 |
0.4 |
0.7–0.8 |
8.8–13.4 |
3.3–5.4 |
A. torridus
1–1.1
|
1.6–1.9 |
0.3 |
0.6–0.7 |
10.3–14.4 |
3.4–4.1 |
A. coylei
0.9
|
1.3 |
0.2 |
0.5 |
12.3 |
3.8 |
Holotype
male (
Fig. 2
).
Carapace
3.7 long, 3.2 wide, pars cephalica 2.2 long. Thoracic groove slightly oval, pit-like, anterior edge recurved. Cluster of postocular setae forming small backwards-pointing triangle.
Leg I
IFL 4.2, ITL 2.7, IML 2.6, ITarL 1.5. Dorsal setae on tibia and metatarsus mostly appressed, ventral ensiform macrosetae on tibia and metatarsus numerous, tibial dorsal macrosetae erect.
Pedipalp
PFL 4.7, PPL 2.8, PTL 3.9, PTX 2.0, PTT 0.7, PED 1.0, PCA 0.4. Tibia elongate, roughly banana-shaped, hirsute. Palpal bulb with loosely looped sperm reservoir, base of embolus relatively distant from base of inner conductor sclerite (ICS).
Sternum
SL 2.2, SW 1.9, posterior sternal sigilla moderately close (PSS 0.5), oval-shaped, faint.
Abdomen
tergite II large, tergite III subequal to tergite II, boundary indistinct; tergite I minute.
Paratype
female (
Figs 3–4
).
Carapace
6.5 long, 4.9 wide, pars cephalica 4.2 long. Thoracic groove pit-like, anterior edge slightly recurved. Cluster of postocular setae forming small backwards-pointing triangle.
Chelicerae
with row of 2 retrolateral macroteeth, 6 prolateral macroteeth, 7–8 intermediate microteeth.
Leg I
IFL 4.0, ITL 2.4, IML 1.8, ITarL 1.0, 11 ensiform macrosetae on metatarsus.
Leg IV
(right) IVFL 4.1, IVTL 2.1, IVML 3.2, IVTarL 1.4.
Pedipalp
tarsus with 7 ensiform macrosetae on prolateral surface, 3 ensiform macrosetae on retrolateral surface. Sternum SL 4.2, SW 3.4, posterior sternal sigilla well separated (PSS = 0.7), large (PSL = 0.6), oval-shaped. Seminal receptacles with relatively large bulbs as compared to stalk diameter, stalks short, with single bend.
Other records.
The species is known from 20 other geographic locations, represented by
28 adult
specimens (Table 1). Two other locations are represented only by immature specimens (sites 3 and 23, Table 1); DNA analyses indicate that these immatures are
A. coylei
specimens.
FIGURE 1.
A) Adult female
Aliatypus coylei
(MY4194), Harlan Mountain Road, Gabilan Range, San Benito County; B)
Aliatypus
trapdoor, Harlan Mountain Road, Gabilan Range, San Benito County; C) Known distribution of
Aliatypus coylei
.
Site numbers correspond to Table 1; some geographically adjacent sites are represented by a single white circle. Regional records of other
Aliatypus
species as follows: red dots =
A. janus
, blue dots =
A. torridus
(records from Coyle 1974, Coye & Icenogle 1994; Satler
et al. in review
; personal observations). San Luc = Santa Lucia Range, Gab = Gabilan Range, Diablo = Diablo Range.
FIGURE 2.
Male holotype, MY999 (CASENT9039430), W of Arroyo Center (site 19): A) carapace and abdomen, viewed dorsally, B) left pedipalp, viewed retrolaterally, C) left leg I, viewed retrolaterally, D) sternum and chelicerae, viewed ventrally, E) palpal bulb, viewed ventrally. Scale bar A–D = 1 mm, E = 0.5 mm.
Geographic variation.
A male from site 9 (Table 1) is smaller-bodied than the
holotype
male, but otherwise conforms to the
holotype
in shape of palpal tibia, details of the bulb, and shape of sternal sigilla. Female specimens vary noticeably in shape of the seminal receptacles, although most possess relatively large bulbs, with short, narrow stalks. An exception is MY2671 from site 24 (Table 1), with seminal receptacles not unlike
A. gulosus
Coyle
, with straight, short stalks leading to bulbs of only slightly larger diameter (
Fig. 3
L). Specimens from several sites include more stalk bends than the
holotype
female (e.g.,
Fig. 3
E, G, J, K). The general characteristics of sternal sigilla morphology (large, fairly close together, diverging oblong shape) is similar among female specimens, with minor exceptions. For example, specimen MY374 from site 12 (Table 1) has relatively widely spaced, less elongate posterior sigilla (
Fig. 4
B). Several other females have irregular-shaped sigilla (e.g.,
Figs 4
D, E).
Distribution.
Most records are from the southern Coast Ranges, including the Gabilan, Diablo,
Santa Lucia
, and La Panza Ranges. Two isolated records are from further south in California, with a record from the Transverse Ranges (site 23, Table 1,
Fig. 1
), and a record from the Santa Monica Mountains (site 24, Table 1,
Fig. 1
).
Natural history.
Consistent with the relatively broad geographic distribution of this species, populations have been found in several habitat
types
including coastal redwood forest, Monterey Pine forest, mixed
Pinus sabiniana
/
Quercus
woodland, and habitats dominated by
Adenostemma
/
Arctostaphylos
chaparral scrub. Essentially all collections are from more mesic microhabitats within these larger habitat
types
, including north-facing ravines, shaded banks, and shaded roadcuts. Burrows have been found on essentially vertical banks (e.g., sites 1, 5, 13, 15), but also on shallower slopes (e.g., sites 10, 12, 22). Many burrows were characterized by almost a complete absence of silk. Adult females have been collected throughout the year; two adult male specimens were collected from burrows in October (Table 1).