A review of the spider genus Porrhomma (Araneae, Linyphiidae)
Author
Růžička, Vlastimil
text
Zootaxa
2018
2018-09-14
4481
1
1
75
journal article
29177
10.11646/zootaxa.4481.1.1
ac892ad5-037a-4486-9fdb-3082b98cbf49
1175-5326
1454736
BFC4982D-BB84-4141-BDFD-203F23CD1585
Porrhomma pallidum
Jackson, 1913
Figs. 45A–F
.
Porrhomma pallidum
—
Jackson (1913)
: p. 38, Pl. II,
Figs. 18
,
32
(descr.
♂
♀
).
P. pallidum affinis
—
Miller & Kratochvíl (1940)
: p. 189, Figs. 12.3, 13.1–2 (descr.
♂
♀
); new synonymy.
Material
examined.
CZECHIA
:
Krkonoše Mts.
National Park, Harrachov,
Mrtvý Vrch Hill
,
1982–1989
, 4 Ƌ
5 ♀
, leg. J. Vaněk. Tisá, Tiské Stěny Rock Walls Reserve,
12 May 1991
, 2 Ƌ 3 ♀,
leg.
F. Růžička. Nižbor
,
Vůznice Reserve
, 14
Jun
–2
Jul 1993, 1
Ƌ
1 ♀
, leg. F. Pojer. Verneřice-Loučky, Bobří Soutěska Gorge Reserve,
1 Jun 1986
–
16 May 1987
, 1 ♀,
19 Oct 1999
, 1 ♂ 1 ♀;
Teplice nad Metují
,
Adršpašsko-Teplické Skály Rocks Reserve
,
24 Oct 1987
,
1 ♂
2 ♀
;
Šumava Mts.
,
Srní
,
Vydra River Valley
,
23 Jul 1992
,
1 ♀
;
Šumava Mts.
,
Stachy-Popelná
,
Obří Zámek Hill
,
6 Oct 1985
–
4 Oct 1986
,
1 ♂
;
Lnáře-Tchořovice
,
30 May 1975
,
1 ♀
; Rokycany-Svojkovice, Žďár Hill,
5 May 1998
, 1 ♀; leg. V.
Růžička. Teplice nad Metují
,
Adršpašsko-Teplické Skály Rocks
,
2006–2009
,
9 ♂
10 ♀
, leg.
R. Mlejnek
(
IECA
)
.
SLOVAKIA
:
Námestovo
,
23 Jun 1971
, 1 Ƌ, leg.
J. Svatoň
(
WSM
)
. UNITED KINGDOM:
Scotland
, Tentsmuir
Coast
,
21 Jun 1966
,
2 ♀
(
AMNH
)
.
Diagnosis.
Females of
P. pallidum
are similar to those of
P. altaica
,
P. egeria
,
P. campbelli
and
P. terrestre
in having the simplest vulva (the spermathecae are formed immediately behind the side loop) but can be distinguished by appendices oriented towards the abdominal wall (
Figs. 45C–F
). On the other hand, males of
P. pallidum
are similar to those of
P. borgesi
,
P. cambridgei
,
P. convexum
,
P. errans
,
P. nekolai
,
P. oblitum
,
P. pygmaeum
and
P. rosenhaueri
in having embolus of middle length with a narrow velum and ARP of the form of a bird head (
Fig. 45B
). Males of
P. pallidum
can be distinguished by the following combination of characters: yellow-brown carapace,
0.60–0.69 mm
wide, eyes normal, Fe I–II with dorsal spines, Mt without spines.
Description.
♀
(from Srní,
Czechia
,
23 Jul 1992
). Carapace yellow-brown,
0.63 mm
wide, PME–PME = 1.3 (
Fig. 45A
). Abdomen pale. Fe I–II with one dorsal spine, Fe I with one prolateral spine. Ti I with one prolateral spine, Ti I–II with one retrolateral spine. Tm Mt I = 0.35, Mt I/CW = 0.88.
FIGURE 43.
A–E.
Porrhomma okhawai
from Tochigi Prefecture, Honshu Island, Japan. A, femur I. B, embolic section. C, epigynum. D–E, vulva, ventral and dorsal. Redrawn after Saito (1977b).
FIGURE 44.
Records of
Porrhomma ohkawai
. Tochigi Prefecture, Honshu Island, Japan.
Spermathecae start at the midway of the ascending part of the copulatory ducts. Main sacks oriented towards abdomen. Appendices oriented towards the abdominal wall (
Figs. 45C–F
).
Ƌ (from Nižbor, Czechia,
14 Jun–2 Jul 1993
). Embolus of middle length with a narrow velum. ARP has the form of a bird head (
Fig. 45B
).
Variation. Ƌ
♀
. Carapace
0.60–0.69 mm
wide. Tm Mt I = 0.30–0.39, Mt I/CW = 0.79–0.92 (n = 37).
Comments.
The subspecies
P. p. affinis
was described by
Miller & Kratochvíl (1940)
according to one male and several females collected in High Tatras,
Slovakia
. The
type
material is not available (Růžička
et al.
2008). I found all details in the structure of copulatory organs to be fully within the frame of the natural variability of
P. pallidum
.
Ecology.
The species occurs under stones in scree slopes, scree forests, in cold habitats such as rock gorges, spruce forests, peat bogs.
Note.
All records of
P. pallidum
in
Altai
Mountains are misidentification and actually refer to
P. altaica
new species
(see above).
Global distribution.
Eurasia after Helsdingen (2017), Mikhailov (2013) and
Tanasevitch (2009)
. See
Fig. 46
.