The spider family Micropholcommatidae (Arachnida: Araneae: Araneoidea): a relimitation and revision at the generic level
Author
Rix, Michael
Western Australian Museum, Welshpool DC, Perth, Australia
Author
Harvey, Mark
Western Australian Museum, Perth, Welshpool, Australia
text
ZooKeys
2010
2010-02-22
36
36
1
321
journal article
22759
10.3897/zookeys.36.306
4db6b327-7482-432e-a5f6-36f91c79fef3
1313–2970
576620
ADCACC88-6C78-4386-8E33-3F98234ECE92
Genus
Micropholcomma
Crosby & Bishop, 1927
Micropholcomma
Crosby & Bishop, 1927: 152
.
Type
species by original designation
Micropholcomma caeligenus
Crosby & Bishop, 1927
.
Roewer, 1942: 392
.
Hickman, 1944: 183
.
Bonnet, 1957: 2905
.
Forster, 1959: 297
.
Hickman, 1981: 65
.
Brignoli, 1983: 374
. Rix, 2008: 343.
Platnick, 2009
.
Microlinypheus
Butler, 1932: 103
.
Type
species by monotypy
Microlinypheus bryophilus
Butler, 1932
.
Roewer, 1942: 617
. Synonymised by
Hickman, 1944: 186
.
Bonnet, 1957: 2885
.
Plectochetos
Butler, 1932: 106
.
Type
species by monotypy
Plectochetos longissimus
Butler, 1932
.
Roewer, 1942: 617
.
Bonnet, 1958: 3707
. Synonymised by
Forster, 1959: 297
.
Affinities
.
The genus
Micropholcomma
appears to be the sister-lineage to
Pua novaezealandiae
from
New Zealand
(
Fig. 4
).
Diagnosis
.
Species of
Micropholcomma
can be distinguished from all other
Micropholcommatini
except
Pua novaezealandiae
by the presence of a normal, non-bifurcate embolus (
Fig. 9A
); and can be distinguished from
Pua
by the presence of a long embolus (length> 5× width) which is usually looped or coiled (
Figs 9A
, 12A, 17B). Other diagnostic characters include the presence (and presumed retention) of posterior tracheae (shared with
Gigiella
) and the presence of a male leg I-pedipalpal stridulatory system (Fig. 21D).
Description
.
Very small, entelegyne
Araneoidea
; total length 0.70 to 1.30.
Cephalothorax
: Carapace without glandular depressions above maxillae; cuticle without glandular pits (Fig. 18C); margins fused to sternum via pleural sclerites. Eight (Fig. 18C), rarely six or (in troglomorphic taxa) fewer eyes present on anterior margin of pars cephalica; AME, if present, smallest. Chelicerae with or without bulging anterior projections in males; promargin with true teeth, a pair of fused setal sockets adjacent to base of fang and single peg tooth in males (Fig. 19F).
Legs and female pedipalp
: Legs three-clawed (
Fig. 20D
), covered with smooth or serrate hair-like setae; femur I of males with prolateral stridulatory denticles (Fig. 18C). Trichobothria present on legs; tibiae each with two or three trichobothria (
Fig. 20C
); metatarsi without trichobothria. Female pedipalp four-segmented (with fused tibiatarsus) or reduced to a vestigial nubbin; claw absent (Figs 19C–D).
Abdomen
: Abdomen oval or globose; anterior sclerite present around epigastric region and petiole; large dorsal scute present on males (Fig. 14), absent (Fig. 16B) or (rarely) present (Fig. 13B) on females; lateral sclerotic strips present on males; posterior sclerotic ring surrounding spinnerets and colulus. Six spinnerets situated posterior to fleshy colulus (
Figs 22A, 22C
,
23
A–B); PMS of
M. bryophilum
with single medial AC gland spigot; PLS of
M. bryophilum
with complete triad. Anterior tracheal system welldeveloped, with relatively large lateral atria and multiple radiating tracheae (Fig. 15B); second tracheal tubes on each side looping mesally and extending through petiole into cephalothorax (Fig. 12D); posterior tracheal spiracle present, tracheae quadritracheate.
Genitalia
: Male pedipalp (Fig. 21) small to large, relatively simple; patella with distally-directed, flanged or hooked ligulate retrolateral apophysis and retrolateral stridulatory ridges; tegulum smooth, with curved evaginated tegular ridge; embolus exposed, long (length> 5× width), usually looped or coiled. Female genitalia (Figs 15A–E) with pair of separate, globular anterior spermathecae; insemination ducts coiled around fertilisation ducts; fertilisation ducts posteriorly-directed.
Distribution
.
Eastern and western mainland
Australia
and
Tasmania
(Fig. 217). Two undescribed female specimens from Rivière Bleue and Mont Mou,
New Caledonia
(QMB
S60522
, QMB S72474) probably also belong in this genus, but males are required to confirm the identification.
Composition
.
Seven described species,
Micropholcomma bryophilum
(
Butler, 1932
)
,
M. caeligenum
Crosby & Bishop, 1927
,
M. linnaei
Rix, 2008
,
M. longissimum
(
Butler, 1932
)
,
M. mirum
Hickman, 1944
,
M. parmatum
Hickman, 1944
,
M. turbans
Hickman, 1981
, and the new species
M. junee
. Undescribed species are also known from throughout the range of the genus.
Nomenclatural
remarks.
The gender of the genus name “
Micropholcomma
” was not specified by
Crosby and Bishop (1927)
, although the
type
species was described with a masculine specific epithet (as
M
. “
caeligenus
”). The name
Micropholcomma
was clearly derived from the theridiid taxon name “
Pholcomma
” Thorell, and as highlighted by
Levi (1964)
, this name should be treated as neuter. To this end,
Brignoli (1983)
and
Davies (1985)
amended the suffix endings of the species names, all of which were previously masculine or feminine.