Transfer of the Namibian Argistes africanus Simon, 1910 (Araneae: Liocranidae) to Afroceto Lyle & Haddad, 2010 (Trachelidae), with a new synonym
Author
Haddad, Charles R.
text
Zootaxa
2019
2019-03-27
4571
3
446
450
journal article
27825
10.11646/zootaxa.4571.3.13
1af03d39-60ed-46dc-b422-7706bcca43f9
1175-5326
2612677
74CC2368-236C-48BB-8DAD-6348832E263D
Afroceto africana
(
Simon, 1910
)
comb. nov.
Figs 1–8
Argistes africanus
Simon, 1910
: 201
[subadult
♀
holotype
:
NAMIBIA
: Lüderitzbucht, leg. Schultze, ZMB 27144—examined].
Afroceto arca
Lyle & Haddad, 2010
: 339
, figs 3, 4, 43–49 (
♀
♂
),
syn. nov.
Remarks.
Although both the original description of
Argistes africanus
(
Simon 1910
)
and the eighth publication in the series on the Arachnida
types
in ZMB (
Moritz & Fischer 1988
) indicated that the
type
specimen is a female, detailed examination showed that it is, in fact, a subadult female without a developed epigyne (
Figs 1–3
). The
type
shares a number of characters with the trachelid
Afroceto arca
(
Figs 4–6
), which is the only representative of the genus that has been recorded from
Namibia
to date (
Lyle & Haddad 2010
;
Lyle 2015
;
World Spider Catalog 2018
). It, together with the
type
species
A. martini
(Simon, 1897)
and
A. plana
Lyle & Haddad, 2010
, are the only three of the 16 described
Afroceto
that have been recorded outside of
South Africa
and the enclave of
Lesotho
.
FIGURES 1–6.
Morphology of
Afroceto africana
(Simon, 1910)
comb. nov.
: 1–3. Holotype subadult female of
Argistes africanus
Simon, 1910
; 4–6. Female of
Afroceto arca
Lyle & Haddad, 2010
syn. nov.
: 1, 4. Habitus, dorsal view; 2, 5. Carapace, dorsal view; 3, 6. Abdomen, ventral view. Scale bars: 1 mm.
FIGURES 7–8.
Morphology of
Afroceto africana
(Simon, 1910)
comb. nov.
female: 7. Sternum and mouthparts; 8. Epigyne, ventral view. Scale bars: 0.5 mm.
Despite its poor condition, the type of
Argistes africanus
shows traces of a branched chevron marking dorsally on the abdomen, a feature unique to
Afroceto arca
and
A. corcula
Lyle & Haddad, 2010
amongst members of that genus (see
Lyle & Haddad 2010
: figs 1–22). The general carapace shape, proportions and eye arrangement of the two species are also similar (compare
Figs 2 and 5
), as are the proportions of the ovoid abdomen and general structure of the spinnerets (compare
Figs 3 and 6
). The characteristic ventral markings of
A. arca
(
Fig. 6
) are not evident in the faded
holotype
of
Argistes africanus
(
Fig. 3
), nor did
Simon (1910)
mention them in the original description, only describing the dorsal and lateral markings and indicating the venter as “clay-coloured”: “
Abdomen longe oblongum, superne cinereo testaceum, maculis nigris triseriatis, medianis subtriquetris, lateralibus longis et obliquis, ornatum, subtus albo-testaceum
.”
The only known record of
Afroceto
from
Namibia
to date (
Lyle & Haddad 2010
) is a single male specimen from Vogelfederberg [
23°03'S
,
14°59'E
], which is approximately
400 km
north of Lüderitzbucht [modern Lüderitz,
26°38'S
,
15°09'E
], the
type
locality of
Argistes africanus
(
Fig. 9
). The two localities are separated by the Namib Desert, one of the most hostile places on earth, but to the east of this desert are relatively arid but more hospitable Nama Karoo and Savanna habitats. Considering the widespread distribution of
Afroceto arca
in
South Africa
, including the latter two vegetation
types
(
Lyle & Haddad 2010
), it is likely that the two species are conspecific.
Argistes africanus
is hereby transferred to
Afroceto
as
A. africana
(
Simon, 1910
)
comb. nov.
, and proposed as a senior synonym of
A. arca
syn. nov.
.
Description.
See
Lyle & Haddad (2010)
for description of both sexes.
Diagnosis.
Afroceto africana
comb. nov.
is a typical member of the genus, which is characterized from other Afrotropical
Trachelidae
by their relatively large size, the presence of several strong prolateral spines on the anterior femora, a dorsal scutum in males (usually absent in females), and the presence of many long ventral cusps on the anterior legs of males (and sometimes females too, but not including
A. africana
comb. nov.
; see
Lyle & Haddad 2010
). The genus has a shield-shaped sternum and slightly bulging chelicerae (
Fig. 7
), as do most Afrotropical trachelids.
Afroceto africana
comb. nov.
can be easily recognized from congeners by the distinct shape of the epigyne, with a broad, anteriorly arched, strongly sclerotised atrium that has a generalized keyhole shape (
Fig. 8
), and the males with a short, distally coiled embolus (see
Lyle & Haddad 2010
: figs 46–49).
New records.
SOUTH AFRICA
:
Eastern Cape
:
Nearly
7 km
S of Hogsback
on R345, isolated tree, roadside,
32°38.831'S
,
26°55.375'E
,
715 m
a.s.l.
, 1.×.2011, leg.
J. Neethling
& C. Luwes (canopy fogging),
1♂
1♀
(
NCA 2012
/1641)
.
Free State
:
Brandfort district
,
Amanzi Private Game Reserve
,
28°35.428'S
,
26°26.067'E
,
1425 m
a.s.l.
,
17.XII.2016
, leg.
C. Haddad
(hand collecting around buildings),
2♂
(
NCA 2016
/3036);
Brandfort district
,
Krugersdrift Dam
,
28°42'S
,
25°55'E
,
1.I.1987
, leg.
Museum
staff (in canal),
1♀
(
NMBA 9057
)
;
Fauresmith district
,
Farm Boschrand
,
29°56'S
,
24°48'E
,
22.III.2005
, leg.
L. Lotz
(sweeping, beating),
1♀
(
NMBA 10
007);
Luckhoff district
,
Farm Bankfontein
,
30°04.421'S
,
24°53.017'E
,
22.I.2015
, leg.
C. Haddad
(hand collecting,
Nama Karoo
veld),
2♀
(
NCA 2015
/1669);
Same
locality,
2.IV.2015
, leg.
University
of the
Free State
students (sifting leaf litter, riparian woodland),
1♀
(
NCA 2015
/2442);
Kalkfontein Dam Nature Reserve
,
29°31.285'S
,
25°16.662'E
,
15.I.2014
, leg.
Y. Marusik
(sifting leaf litter),
2♂
(
NCA 2014
/1069);
Same
locality,
29°31.072'S
,
25°16.091'E
,
28.I.2014
, leg.
N. Josling
(in garden amongst plants),
6♂
1♀
(
NCA 2015
/1910);
Same
locality,
29°31.071'S
,
25°16.069'E
,
6.II.2014
, leg.
N. Josling
(amongst flowers in garden),
1♂
(
NCA 2015
/1981);
Same
locality,
29°31.072'S
,
25°16.091'E
,
12.XI.2013
, leg.
N. Josling
(in wasp nest),
1♀
(
NCA 2015
/1993)
.
Western Cape
:
Jacobsbaai
,
34°21.430'S
,
19°07.557'E
,
8.V.2010
, leg.
C. Haddad
(on wall of house at night),
1♀
(
TMSA 23787
)
;
Matjiesfontein
,
33°13.783'S
,
20°34.818'E
,
900 m
a.s.l.
,
15.X.2015
, leg.
Z. Mbo
(sifting leaf litter),
1♀
(
NCA 2016
/ 2363)
.
Distribution.
Afroceto africana
is widespread in the more mesic Grassland, Nama Karoo and Fynbos habitats of southern Africa, with only a few sporadic records from the moister eastern parts of
South Africa
(
Fig. 9
). All of the new records reported here fall within the known distribution range of the species.